Next Issue
Volume 2, December
Previous Issue
Volume 2, June
 
 

Crystals, Volume 2, Issue 3 (September 2012) – 37 articles , Pages 730-1365

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
495 KiB  
Article
Fluoride Ion as Ligand and Hydrogen Bond Acceptor: Crystal Structures of Two Dinuclear CuII Complexes Built on a Diazecine Template
by Juan Olguín, Sylvain Bernès and Laura Gasque
Crystals 2012, 2(3), 1357-1365; https://doi.org/10.3390/cryst2031357 - 18 Sep 2012
Cited by 5 | Viewed by 6303
Abstract
Two dinuclear CuII complexes based on a diazecine ligand were characterized by X-ray diffraction, one of which includes the rare CuII–F bond, resulting from dissociation of a BF4 ion. The F ligands actively participate in the crystal [...] Read more.
Two dinuclear CuII complexes based on a diazecine ligand were characterized by X-ray diffraction, one of which includes the rare CuII–F bond, resulting from dissociation of a BF4 ion. The F ligands actively participate in the crystal structure, behaving as acceptors for hydrogen bonding. Full article
Show Figures

Graphical abstract

336 KiB  
Article
Temperature-Dependent Ordering of the Methyl Group in the Crystal Structure of 5-(2-Chlorophenyl)-7-ethyl-1H-thieno [2,3-E][1,4]diazepin-2(3H)-one
by Grzegorz Dutkiewicz, Maciej Kubicki, Alaloor S. Dayananda, Hemmige S. Yathirajan and Andagar R. Ramesha
Crystals 2012, 2(3), 1347-1356; https://doi.org/10.3390/cryst2031347 - 18 Sep 2012
Cited by 41 | Viewed by 5176
Abstract
5-(2-Chlorophenyl)-7-ethyl-1H-thieno[2,3-e][1,4]diazepin-2(3H)-one, a close analogue of clotiazepam (full agonist at GABA receptor), crystallizes in monoclinic P21/c space group with a = 15.6941(6) Å, b = 10.7909(4) Å, c = 8.6586(3) Å, and β = 102.184(4)° (at 125 [...] Read more.
5-(2-Chlorophenyl)-7-ethyl-1H-thieno[2,3-e][1,4]diazepin-2(3H)-one, a close analogue of clotiazepam (full agonist at GABA receptor), crystallizes in monoclinic P21/c space group with a = 15.6941(6) Å, b = 10.7909(4) Å, c = 8.6586(3) Å, and β = 102.184(4)° (at 125 K). Seven-Membered diazepine ring has approximate mirror plane of symmetry, planar thieno and phenyl rings are almost perpendicular to one another, dihedral angle between their mean planes is 84.11(5)°. N–H···O hydrogen bonds connect molecules into centrosymmetric dimers which are further expanded into 3D crystal structure with the help of weaker C–H···O and C–H···π interactions. The methyl group is disordered at room temperature, but it gets gradually ordered at lower temperatures and becomes fully ordered at approximately 200 K. The changes in structure with temperature were studied between 125 and 380 K. The unit cell volume—as expected—increases almost monotonically when the temperature rises, but one of the parameters shortens significantly. Full article
Show Figures

Figure 1

3681 KiB  
Review
Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands
by Kyuya Yakushi
Crystals 2012, 2(3), 1291-1346; https://doi.org/10.3390/cryst2031291 - 18 Sep 2012
Cited by 44 | Viewed by 10285
Abstract
This paper reviews charge ordering in the organic conductors, β″-(BEDT-TTF) (TCNQ), θ-(BEDT-TTF)2X, and α-(BEDT-TTF)2X. Here, BEDT-TTF and TCNQ represent bis(ethylenedithio)tetrathiafulvalene and 7,7,8,8-tetracyanoquinodimethane, respectively. These compounds, all of which have a quarter-filled band, were evaluated using infrared and Raman spectroscopy [...] Read more.
This paper reviews charge ordering in the organic conductors, β″-(BEDT-TTF) (TCNQ), θ-(BEDT-TTF)2X, and α-(BEDT-TTF)2X. Here, BEDT-TTF and TCNQ represent bis(ethylenedithio)tetrathiafulvalene and 7,7,8,8-tetracyanoquinodimethane, respectively. These compounds, all of which have a quarter-filled band, were evaluated using infrared and Raman spectroscopy in addition to optical conductivity measurements. It was found that β″-(BEDT-TTF)(TCNQ) changes continuously from a uniform metal to a charge-ordered metal with increasing temperature. Although charge disproportionation was clearly observed, long-range charge order is not realized. Among six θ-type salts, four compounds with a narrow band show the metal-insulator transition. However, they maintain a large amplitude of charge order (Δρ~0.6) in both metallic and insulating phases. In the X = CsZn(SCN)4 salt with intermediate bandwidth, the amplitude of charge order is very small (Δρ < 0.07) over the whole temperature range. However, fluctuation of charge order is indicated in the Raman spectrum and optical conductivity. No indication of the fluctuation of charge order is found in the wide band X = I3 salt. In α-(BEDT-TTF)2I3 the amplitude of charge order changes discontinuously from small amplitude at high temperature to large amplitude (Δρmax~0.6) at low temperature. The long-range charge-ordered state shows ferroelectric polarization with fast optical response. The fluctuation of multiple stripes occurs in the high-temperature metallic phase. Among α-(BEDT-TTF)2MHg(SCN)4 (X = NH4, K, Rb, Tl), the fluctuation of charge order is indicated only in the X = NH4 salt. α′-(BEDT-TTF)2IBr2 shows successive phase transitions to the ferroelectric state keeping a large amplitude of charge order (Δρmax~0.8) over the whole temperature range. It was found that the amplitude and fluctuation of charge order in these compounds is enhanced as the kinetic energy (bandwidth) decreases. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

622 KiB  
Article
Structural and Electrical Properties of the τ-(P-S,S-DMEDT-TTF)2 (AuCl2) (AuCl2)y Compound with (y ≈ 0.9)
by Vassilis Psycharis, George A. Mousdis, Keizo Murata and George C. Papavassiliou
Crystals 2012, 2(3), 1283-1290; https://doi.org/10.3390/cryst2031283 - 03 Sep 2012
Cited by 10 | Viewed by 5620
Abstract
The compound τ-(P-S,S-DMEDT-TTF)2(AuCl2) (AuCl2)y (where P-S,S-DMEDT-TTF is the compound pyrazino-(S,S)-dimethyl-ethylenedithio-tetrathiofulvale) crystallizes in the non-centrosymmetric space group I-42d, with a = 7.3260(1) Å and [...] Read more.
The compound τ-(P-S,S-DMEDT-TTF)2(AuCl2) (AuCl2)y (where P-S,S-DMEDT-TTF is the compound pyrazino-(S,S)-dimethyl-ethylenedithio-tetrathiofulvale) crystallizes in the non-centrosymmetric space group I-42d, with a = 7.3260(1) Å and c = 67.5487(12) Å (RT data) and remains tetragonal in the temperature range from RT to 100 K. This compound is a quasi-two-dimensional material and the relation of the lattice of the order part of the structure created by the donor molecules with that of the disordered anion lattice revealed by intense diffusion streaks give a value of y ≈ 0.9. In contrast to the Br and I analogs or the related compounds which contain the compound ethylenedioxy-S,S-dimethylenedithiotetrathiafulvalene (abbreviated as EDO-S,S-DMEDT-TTF) as donor and which exhibit anisotropic metallic behavior down to low temperature, this compound is anisotropic semiconductor in the same temperature range. The appearance of satellites on the diffraction images recorded below 110 K indicates a structural change. Resistivity measurements show that this material is a semiconductor with anisotropy σac of ca. 400–1400 at room temperature. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

2835 KiB  
Review
Electronic Principles of Hydrogen Incorporation and Dynamics in Metal Hydrides
by Nenad Ivanović, Nikola Novaković, Ivana Radisavljević, Ljiljana Matović and Jasmina Grbović Novaković
Crystals 2012, 2(3), 1261-1282; https://doi.org/10.3390/cryst2031261 - 30 Aug 2012
Cited by 2 | Viewed by 9833
Abstract
An approach to various metal hydrides based on electronic principles is presented. The effective medium theory (EMT) is used to illustrate fundamental aspects of metal-hydrogen interaction and clarify the most important processes taking place during the interaction. The elaboration is extended using the [...] Read more.
An approach to various metal hydrides based on electronic principles is presented. The effective medium theory (EMT) is used to illustrate fundamental aspects of metal-hydrogen interaction and clarify the most important processes taking place during the interaction. The elaboration is extended using the numerous existing results of experiment and calculations, as well as using some new material. In particular, the absorption/desorption of H in the Mg/MgH2 system is analyzed in detail, and all relevant initial structures and processes explained. Reasons for the high stability and slow sorption in this system are noted, and possible solutions proposed. The role of the transition-metal impurities in MgH2 is briefly discussed, and some interesting phenomena, observed in complex intermetallic compounds, are mentioned. The principle mechanism governing the Li-amide/imide transformation is also discussed. Latterly, some perspectives for the metal-hydrides investigation from the electronic point of view are elucidated. Full article
(This article belongs to the Special Issue Hydrogen Storage Alloys)
Show Figures

Figure 1

755 KiB  
Short Note
[Pr2(pdc)3(Hpdc)(H2O)4]n·n(H3hp)·8n(H2O), a One-Dimensional Coordination Polymer Containing PrO6N3 Tri-Capped Trigonal Prisms and PrO8N Mono-Capped Square Anti-Prisms (H2pdc = Pyridine 2,6-Dicarboxylic Acid, C7H5NO4; 3hp = 3-Hydroxy Pyridine, C5H5NO)
by Shahzad Sharif, Onur Sahin, Islam Ullah Khan, Orhan Büyükgüngör and William T. A. Harrison
Crystals 2012, 2(3), 1253-1260; https://doi.org/10.3390/cryst2031253 - 27 Aug 2012
Cited by 3 | Viewed by 6826
Abstract
The synthesis, structure and some properties of the one-dimensional coordination polymer, [Pr2(pdc)3(Hpdc)]n·n(H3hp)·8n(H2O), (H2pdc = pyridine 2,6-dicarboxylic acid, C7H5NO4; 3hp = 3-hydroxypyridine, C5 [...] Read more.
The synthesis, structure and some properties of the one-dimensional coordination polymer, [Pr2(pdc)3(Hpdc)]n·n(H3hp)·8n(H2O), (H2pdc = pyridine 2,6-dicarboxylic acid, C7H5NO4; 3hp = 3-hydroxypyridine, C5H5NO) are described. One of the Pr3+ ions is coordinated by two O,N,O-tridentate pdc2− ligands and one tridentate Hpdc anion to generate a fairly regular PrO6N3 tri-capped trigonal prism, with the N atoms acting as the caps. The second Pr3+ ion is coordinated by one tridentate pdc2− dianion, four water molecules and two monodentate bridging pdc2− ligands to result in a PrO8N coordination polyhedron that approximates to a mono-capped square-anti-prism. The ligands bridge the metal-atom nodes into a chain, which extends in the [100] direction. The H3hp+ cation and uncoordinated water molecules occupy the inter-chain regions and an N–HLO and numerous O–HLO hydrogen bonds consolidate the structure. The H3hp+ species appears to intercalate between pendant pdc rings to consolidate the polymeric structure. Crystal data: 1 (C33H43N5O29Pr2), Mr = 1255.54, triclinic, (No. 2), Z = 2, a = 13.2567(1) Å, b = 13.6304(2) Å, c = 13.6409(2) Å, α = 89.695(1)°, β = 63.049(1)°, γ = 86.105(1)°, V = 2191.16(5) Å3, R(F) = 0.033, wR(F2) = 0.084. Full article
Show Figures

Figure 1

181 KiB  
Short Note
One-Pot Synthesis and Crystal Structure of Methyl 5-Hydroxy-1-phenyl-1H-pyrazole-3-carboxylate
by Aamer Saeed, Ifzan Arshad and Ulrich Flörke
Crystals 2012, 2(3), 1248-1252; https://doi.org/10.3390/cryst2031248 - 27 Aug 2012
Cited by 5 | Viewed by 6142
Abstract
The title compound, Methyl 5-Hydroxy-1-Phenyl-1H-Pyrazole-3-Carboxylate (C11H10N2O3), was prepared by a one-pot, two-component reaction of an equimolar mixture of phenyl hydrazine and dimethyl acetylene dicarboxylate (DMAD) at reflux temperature for 2 h in a [...] Read more.
The title compound, Methyl 5-Hydroxy-1-Phenyl-1H-Pyrazole-3-Carboxylate (C11H10N2O3), was prepared by a one-pot, two-component reaction of an equimolar mixture of phenyl hydrazine and dimethyl acetylene dicarboxylate (DMAD) at reflux temperature for 2 h in a mixture of toluene and dichloromethane as solvent. C11H10N2O3 was crystallized from an ethanol solution in monoclinic space group P21/c with unit cell dimensions a = 9.5408(16), b = 9.5827(16), c = 11.580(2) Å, β = 105.838(3)°, V = 1018.5(3) Å3, Z = 4. Full article
Show Figures

Figure 1

316 KiB  
Article
Crystal and Molecular Structure Studies of Ethyl 4-(4-Hydroxyphenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate and Ethyl 4-(3-Bromophenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate
by Manpreet Kaur, Jerry P. Jasinski, Ray J. Butcher, Hemmige S. Yathirajan, Anil N. Mayekar and Badiadka Narayana
Crystals 2012, 2(3), 1239-1247; https://doi.org/10.3390/cryst2031239 - 27 Aug 2012
Cited by 1 | Viewed by 6223
Abstract
The crystal and molecular structures of the title compounds, ethyl 4-(4-hydroxyphenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate (I) and ethyl 4-(3-bromophenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate (II), are reported and confirmed by single crystal X-ray diffraction data. Compound (I), C26H24O5, crystallizes from [...] Read more.
The crystal and molecular structures of the title compounds, ethyl 4-(4-hydroxyphenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate (I) and ethyl 4-(3-bromophenyl)-6-(6-methoxy-2-naphthyl)-2-oxocyclohex-3-ene-1-carboxylate (II), are reported and confirmed by single crystal X-ray diffraction data. Compound (I), C26H24O5, crystallizes from a methanol solution in the monoclinic C2/c space group with eight molecules in the unit cell. The unit cell parameters are: a = 25.4114(5) Å, b = 8.47440(10) Å, c = 20.6921(4) Å, β = 108.328(2)° and V = 4229.92(13) Å3. Disorder is observed throughout the entire molecule with an occupancy ratio 0.690(2):0.310(2). Compound (II), C26H23O4Br, crystallizes from an ethyl acetate solution in the monoclinic P21/c spacegroup with four molecules in the unit cell. The unit cell parameters are a = 17.8991(9) Å, b = 11.4369(6) Å, c = 10.8507(5) Å, β = 92.428(4)° and V = 2219.25(19) Å3. Disorder is observed in the cyclohexenone ring and the carboxylate group with an occupancy ratio 0.830(6):0.170(6). Weak O–H...O (I) or C–H...O (II) intermolecular interactions are observed which influence crystal packing stability. These chalcone derivative types of molecules are important in their ability to act as activated unsaturated systems in conjugated addition reactions of carbanions in the presence of basic catalysts which exhibit a multitude of biological activities. Full article
Show Figures

Figure 1

1031 KiB  
Article
Organic Semiconductors and Conductors with tert-Butyl Substituents
by Toshiki Higashino, Yuto Akiyama, Hirotaka Kojima, Tadashi Kawamoto and Takehiko Mori
Crystals 2012, 2(3), 1222-1238; https://doi.org/10.3390/cryst2031222 - 22 Aug 2012
Cited by 19 | Viewed by 7174
Abstract
Tetrathiafulvalene (TTF), pentacene, and quarterthiophene with tert-butyl substituents are synthesized, and the crystal structures and the transistor properties are investigated. The tetracyanoquinodimethane (TCNQ) complex of tert-butyl TTF constructs highly one-dimensional segregated columns with tetragonal crystal symmetry. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Graphical abstract

2977 KiB  
Article
Electronic Structure of Cu(tmdt)2 Studied with First-Principles Calculations
by Shoji Ishibashi and Kiyoyuki Terakura
Crystals 2012, 2(3), 1210-1221; https://doi.org/10.3390/cryst2031210 - 21 Aug 2012
Cited by 6 | Viewed by 5940
Abstract
We have studied the electronic structure of Cu(tmdt)2, a material related to single-component molecular conductors, by first-principles calculations. The total energy calculations for several different magnetic configurations show that there is strong antiferromagnetic (AFM) exchange coupling along the crystal a-axis. The [...] Read more.
We have studied the electronic structure of Cu(tmdt)2, a material related to single-component molecular conductors, by first-principles calculations. The total energy calculations for several different magnetic configurations show that there is strong antiferromagnetic (AFM) exchange coupling along the crystal a-axis. The electronic structures are analyzed in terms of the molecular orbitals near the Fermi level of isolated Cu(tmdt)2 molecule. This analysis reveals that the system is characterized by the half-filled pdσ(−) band whose intermolecular hopping integrals have strong one-dimensionality along the crystal a-axis. As the exchange splitting of the band is larger than the band width, the basic mechanism of the AFM exchange coupling is the superexchange. It will also be shown that two more ligand orbitals which are fairly insensitive to magnetism are located near the Fermi level. Because of the presence of these orbitals, the present calculation predicts that Cu(tmdt)2 is metallic even in its AFM state, being inconsistent with the available experiment. Some comments will be made on the difference between Cu(tmdt)2 and Cu(dmdt)2. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

945 KiB  
Communication
Synthesis and Crystal Structure of Benzyl [(1S)-1-(5-amino-1,3,4-oxadiazol-2-yl)-2-phenylethyl]carbamate
by Reik Löser, Martin Nieger and Michael Gütschow
Crystals 2012, 2(3), 1201-1209; https://doi.org/10.3390/cryst2031201 - 20 Aug 2012
Cited by 3 | Viewed by 5453
Abstract
The conversion of Z-phenylalanine hydrazide with cyanogen bromide resulted in the formation of the corresponding 2-amino-1,3,4-oxadiazole by spontaneous cyclization of the intermediary cyanohydrazide. The molecular structure of the product was confirmed by single crystal X-ray diffraction. Crystals of the title compound where obtained [...] Read more.
The conversion of Z-phenylalanine hydrazide with cyanogen bromide resulted in the formation of the corresponding 2-amino-1,3,4-oxadiazole by spontaneous cyclization of the intermediary cyanohydrazide. The molecular structure of the product was confirmed by single crystal X-ray diffraction. Crystals of the title compound where obtained from a saturated solution in a mixture of petroleum ether and ethyl acetate and belong to the monoclinic space group P21 with unit cell parameters a = 9.8152(2) Å, b = 9.6305(2) Å, c = 9.8465(2) Å, β = 116.785(1)°. The asymmetric unit contains one molecule. Full article
Show Figures

Graphical abstract

1278 KiB  
Review
Theories on Frustrated Electrons in Two-Dimensional Organic Solids
by Chisa Hotta
Crystals 2012, 2(3), 1155-1200; https://doi.org/10.3390/cryst2031155 - 20 Aug 2012
Cited by 53 | Viewed by 9888
Abstract
Two-dimensional quarter-filled organic solids are a promising class of materials to realize the strongly correlated insulating states called dimer Mott insulator and charge order. In their conducting layer, the molecules form anisotropic triangular lattices, harboring geometrical frustration effect, which could give rise to [...] Read more.
Two-dimensional quarter-filled organic solids are a promising class of materials to realize the strongly correlated insulating states called dimer Mott insulator and charge order. In their conducting layer, the molecules form anisotropic triangular lattices, harboring geometrical frustration effect, which could give rise to many interesting states of matter in the two insulators and in the metals adjacent to them. This review is concerned with the theoretical studies on such issue over the past ten years, and provides the systematic understanding on exotic metals, dielectrics, and spin liquids, which are the consequences of the competing correlation and fluctuation under frustration. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Graphical abstract

516 KiB  
Short Note
APA2[Zn3(HPO4)4(H2O)2], a Layered Zincophosphate Featuring Template-to-Framework N–H⋯O and “Synergic” Framework-to-Template O–H⋯N Hydrogen Bonds and C–H⋯O Interactions (APA = 2-Amino-1-phenyleneammonium, C6H9N2+)
by Joel C. Aughey, William T. A. Harrison and Alexandra M. Z. Slawin
Crystals 2012, 2(3), 1146-1154; https://doi.org/10.3390/cryst2031146 - 16 Aug 2012
Cited by 1 | Viewed by 6416
Abstract
The crystal structure of APA2[Zn3(HPO4)4(H2O)2] (APA = 2-amino-1-phenylene-ammonium, C6H9N2+) (1), as prepared by a predominantly non-aqueous synthesis, is described and compared to related compounds. [...] Read more.
The crystal structure of APA2[Zn3(HPO4)4(H2O)2] (APA = 2-amino-1-phenylene-ammonium, C6H9N2+) (1), as prepared by a predominantly non-aqueous synthesis, is described and compared to related compounds. 1 is built up from an alternating array of ZnO4 and HPO4 tetrahedra sharing vertices as Zn–O–P bonds to generate infinite anionic sheets. Within these sheets, polyhedral 4-, 6- and 8-rings are apparent. The negative charge of the inorganic layer is balanced by singly-protonated APA template cations and water molecules are also present. The components are linked by Nt–H⋯Of, Of–H⋯Ow, Ow–H⋯Of and Of–H⋯Nt (t = template, f = framework, w = water) hydrogen bonds: the last of these represents an unusual framework-to-template interaction. Weak Ct–H⋯Of links may also play a role in consolidating the structure. Crystal data: 1 (C12H26N4O18P4Zn3), Mr = 834.36, monoclinic, C2/c (No. 15), Z = 4, a = 20.194 (8) Å, b = 8.682 (3) Å, c = 15.123 (6) Å, β = 91.510 (11)°, V = 2650.5 (17) Å3, R(F) = 0.048, wR(F2) = 0.112. Full article
Show Figures

Figure 1

1391 KiB  
Article
The Short Series of the Oxygen-Poor Lanthanide Oxide Selenides M10OSe14 with M = La–Nd
by Frank A. Weber, Christian M. Schurz, Susanne Frunder, Charlotte F. Kuhn and Thomas Schleid
Crystals 2012, 2(3), 1136-1145; https://doi.org/10.3390/cryst2031136 - 16 Aug 2012
Cited by 8 | Viewed by 5263
Abstract
Single crystals and phase pure samples of oxygen-poor ternary lanthanide oxide selenides with the composition M10OSe14 (M = La–Nd; tetragonal, I41/acd; a = 1592.0–1559.8 pm, c = 2106.5–2062.9 pm) could be obtained by reacting [...] Read more.
Single crystals and phase pure samples of oxygen-poor ternary lanthanide oxide selenides with the composition M10OSe14 (M = La–Nd; tetragonal, I41/acd; a = 1592.0–1559.8 pm, c = 2106.5–2062.9 pm) could be obtained by reacting the corresponding metals, selenium and selenium dioxide as oxygen source. Their crystal structures are isotypic with Pr10OS14 and thus contain isolated [OM4]10+ tetrahedra (d(O2–M3+) = 243–248 pm) embedded in a complex anionic {[M6Se14]10–} lanthanide selenide matrix (d(M3+–Se2–) = 288–358 pm). All three crystallographically independent M3+ cations exhibit eight contacts to chalcogenide anions (O2– and/or Se2–) resulting in the formation of bicapped trigonal prismatic coordination polyhedra. The optical band gaps of the oxide selenides M10OSe14 amount to values between 1.89 and 2.04 eV indicating wide band-gap semiconductors. Full article
Show Figures

Figure 1

1343 KiB  
Review
1H and 195Pt NMR Study of the Parallel Two-Chain Compound Per2[Pt(mnt)2]
by Elizabeth L. Green, Lloyd L. Lumata, James S. Brooks, Phil Kuhns, Arneil Reyes, Stuart E. Brown and Manuel Almeida
Crystals 2012, 2(3), 1116-1135; https://doi.org/10.3390/cryst2031116 - 16 Aug 2012
Cited by 3 | Viewed by 6897
Abstract
1H and 195Pt NMR are used to probe the spin ½ anion chain in the quasi-one-dimensional conductor Per2[Pt(mnt)2], which exhibits nearly simultaneous charge density wave (CDW) and spin-Peierls (SP) transitions at low temperatures (Tc ~ 8 [...] Read more.
1H and 195Pt NMR are used to probe the spin ½ anion chain in the quasi-one-dimensional conductor Per2[Pt(mnt)2], which exhibits nearly simultaneous charge density wave (CDW) and spin-Peierls (SP) transitions at low temperatures (Tc ~ 8 K). Below Tc the [Pt(mnt)2] chain forms a spin-singlet state that is evident in 1H NMR spectra and spin relaxation (1/T1) rates; however minority unpaired Pt spins may remain in the SP ground state. With increasing magnetic field, the SP and CDW order parameters decrease in unison, indicating they are coupled up to a critical field Bc ~ 20 T. Above Bc, the spin singlet evolves into a spin-polarized configuration. The 195Pt NMR signals vanish as either Tc or Bc are approached from within the SP ground state, suggesting the hyperfine field of the Pt nucleus is significantly stronger than at the proton sites. Simulations yield a consistent picture of the angular, temperature, and magnetic field-dependent spectral features. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Graphical abstract

273 KiB  
Article
Synthesis, Characterization and Crystal Structures of 3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carboxamide and 3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide
by Jerry P. Jasinski, James A. Golen, Seranthimata Samshuddin, Badiadka Narayana and Hemmige S. Yathirajan
Crystals 2012, 2(3), 1108-1115; https://doi.org/10.3390/cryst2031108 - 15 Aug 2012
Cited by 11 | Viewed by 6142
Abstract
Two new pyrazoline derivatives, 3,5-bis(4-fluorophenyl)-4,5-dihydropyrazole-1-carboxamide (1) and 3,5-bis(4-fluorophenyl)-4,5-dihydropyrazole-1-carbothioamide (2), were synthesized by reacting 4,4'-difluoro chalcone with semicarbazide hydrochloride and thiosemicarbazide in ethanolic sodium hydroxide solution. Both the compounds were confirmed by single crystal X-ray diffraction data and supported by [...] Read more.
Two new pyrazoline derivatives, 3,5-bis(4-fluorophenyl)-4,5-dihydropyrazole-1-carboxamide (1) and 3,5-bis(4-fluorophenyl)-4,5-dihydropyrazole-1-carbothioamide (2), were synthesized by reacting 4,4'-difluoro chalcone with semicarbazide hydrochloride and thiosemicarbazide in ethanolic sodium hydroxide solution. Both the compounds were confirmed by single crystal X-ray diffraction data and supported by IR, NMR, and mass spectral data. In 1, crystal packing is stabilized by N–H…O hydrogen bonds and weak N–H...N, N–H…F and C–H…F intermolecular interactions. In 2, only weak N–H…F and N–H…S intermolecular interactions are observed. Crystal data: C16H13F2N3O, (1), Mr = 301.29, monoclinic, C2/c, a = 17.6219(6) Å, b = 10.8735(3) Å, c = 15.3216(5) Å, β = 102.864(3)°, V = 2862.11(16) Å3, Z = 8, T = 173 K, R(F) = 0.0511, wR(F2) = 0.1333; C16H13F2N3S, (2), Mr = 317.35, monoclinic, P21/c, a = 14.339(2) Å, b = 11.1478(17) Å, c = 9.541(2)(5) Å, β = 107.007(18)°, V = 1458.5(5) Å3, Z = 4, T = 173 K, R(F) = 0.0413, wR(F2) = 0.0959. Full article
Show Figures

Figure 1

1346 KiB  
Article
Synthesis, Structures and Properties of Molecular Conductors Based on Bis-Fused Donors Composed of (Thio)Pyran-4-ylidene-1,3-dithiole and Tetraselenafulvalene
by Ken-ichi Ishidzu, Minoru Ashizawa, Masaki Watanabe, Takashi Shirahata and Yohji Misaki
Crystals 2012, 2(3), 1092-1107; https://doi.org/10.3390/cryst2031092 - 09 Aug 2012
Cited by 4 | Viewed by 6055
Abstract
Bis-fused donors composed of (thio)pyran-4-ylidene-1,3-dithiole and tetraselenafulvalene (1a, 2a) and their bis(methylthio) derivatives (1b, 2b) were synthesized. Cyclic voltamograms of all the donors consisted of four pairs of one-electron redox waves, and it was suggested that a [...] Read more.
Bis-fused donors composed of (thio)pyran-4-ylidene-1,3-dithiole and tetraselenafulvalene (1a, 2a) and their bis(methylthio) derivatives (1b, 2b) were synthesized. Cyclic voltamograms of all the donors consisted of four pairs of one-electron redox waves, and it was suggested that a positive charge of 1+• and 2+• distributed mainly on the (thio)pyran-4-ylidene-1,3-dithiole moiety. X-ray structure analysis revealed that (1b)PF6(C6H5Cl)0.5 and (2b)PF6(C6H5Cl) formed one-dimensional conducting stacks in which the donors were dimerized or tetramerized. In those salts, intramolecular charge disproportionation of the donors was suggested by X-ray structure analysis and density functional theory (DFT) calculation with UB3LYP/6-31G(d) basis function. A tight-binding band calculation suggested that these materials were band insulators. All the donors gave highly conducting TCNQ (7,7,8,8-tetracyanoquinodimethane) complexes and I3 salts (σrt = 0.3–19 S cm−1 on a compressed pellet) with very low activation energies of 0.017–0.040 eV, while single crystals of (1b)PF6(C6H5Cl)0.5 and (2b)PF6(C6H5Cl) exhibited semiconductive behavior with large activation energies (Ea = 0.16–0.22 eV). Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

625 KiB  
Short Note
[KDy(Hptc)3(H3ptc)]n·2n(Hbipy)·5n(H2O), a Layered Coordination Polymer Containing DyO6N3 Tri-Capped Trigonal Prisms (H3ptc = Pyridine 2,4,6-Tricarboxylic Acid, C8H5NO6; Bipy = 2,2'-Bipyridine, C10H8N2)
by Shoaib Anwar, Irfana Mariam, Islam Ullah Khan, Ejaz, William T. A. Harrison and Sohail Anwar
Crystals 2012, 2(3), 1084-1091; https://doi.org/10.3390/cryst2031084 - 03 Aug 2012
Cited by 1 | Viewed by 6311
Abstract
The synthesis, structure and properties of the bimetallic layered coordination polymer, [KDy(C8H3NO6)3(C8H5NO6)]n·2n(C10H9N2)·5n(H2O) = [KDy(Hptc)3 [...] Read more.
The synthesis, structure and properties of the bimetallic layered coordination polymer, [KDy(C8H3NO6)3(C8H5NO6)]n·2n(C10H9N2)·5n(H2O) = [KDy(Hptc)3(H3ptc)]n·2n(Hbipy)·5n(H2O), are described. The Dy3+ ion is coordinated by three O,N,O-tridentate doubly-deprotonated pyridine tri-carboxylate (Hptc) ligands to generate a fairly regular DyO6N3 tri-capped trigonal prism, with the N atoms acting as the caps. The potassium ion is coordinated by an O,N,O-tridentate H3ptc molecule as well as monodentate and bidentate Hptc ligands to result in an irregular KNO9 coordination geometry. The ligands bridge the metal-atom nodes into a bimetallic, layered, coordination polymer, which extends as corrugated layers in the (010) plane, with the mono-protonated bipyridine cations and water molecules occupying the inter-layer regions: Unlike related structures, there are no dysprosium–water bonds. Many O–HLO and N–HLO hydrogen bonds consolidate the structure. Characterization and bioactivity data are described. Crystal data: C52H42DyKN8O29, Mr = 1444.54, triclinic, (No. 2), Z = 2, a = 9.188(2) Å, b = 15.7332(17) Å, c = 19.1664(19) Å, α = 92.797(6)°, β = 92.319(7)°, γ = 91.273(9)°, V = 2764.3(7) Å3, R(F) = 0.029, wR(F2) = 0.084. Full article
Show Figures

Figure 1

1621 KiB  
Review
Photoinduced Phase Transition in Strongly Electron-Lattice and Electron–Electron Correlated Molecular Crystals
by Tadahiko Ishikawa, Ken Onda and Shin-ya Koshihara
Crystals 2012, 2(3), 1067-1083; https://doi.org/10.3390/cryst2031067 - 27 Jul 2012
Cited by 1 | Viewed by 7255
Abstract
Strongly electron-lattice- and electron-electron-correlated molecular crystals, such as charge transfer (CT) complexes, are often sensitive to external stimuli, e.g., photoexcitation, due to the cooperative or competitive correlation of various interactions present in the crystals. These crystals are thus productive targets for studying photoinduced [...] Read more.
Strongly electron-lattice- and electron-electron-correlated molecular crystals, such as charge transfer (CT) complexes, are often sensitive to external stimuli, e.g., photoexcitation, due to the cooperative or competitive correlation of various interactions present in the crystals. These crystals are thus productive targets for studying photoinduced phase transitions (PIPTs). Recent advancements in research on the PIPT of CT complexes, especially Et2Me2Sb[Pd(dmit)2]2 and (EDO-TTF)2PF6, are reviewed in this report. The former exhibits a photoinduced insulator-to-insulator phase transition with clearly assigned spectral change. We demonstrate how to find the dynamics of PIPT using this system. The latter exhibits a photoinduced hidden state as an initial PIPT process. Wide energy ranged time-resolved spectroscopy can probe many kinds of photo-absorption processes, i.e., intra-molecular and inter-molecular electron excitations and intramolecular and electron-molecular vibrations. The photoinduced spectral changes in these photo-absorption processes reveal various aspects of the dynamics of PIPT, including electronic structural changes, lattice structural changes, and molecular deformations. The complexities of the dynamics of the latter system were revealed by our measurements. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Graphical abstract

309 KiB  
Article
Crystal and Molecular Structures of Two 2-Aminothiophene Derivatives
by Maciej Kubicki, Grzegorz Dutkiewicz, Hemmige S. Yathirajan, Pankaj Dawar, Andagar R. Ramesha and Alaloor S. Dayananda
Crystals 2012, 2(3), 1058-1066; https://doi.org/10.3390/cryst2031058 - 27 Jul 2012
Cited by 11 | Viewed by 5317
Abstract
The crystal and molecular structures of two 2-aminothiophene derivatives, potential allosteric enhancers at the human A1 adenosine receptor, are reported. (2-Amino-4,5,6,7-tetrahydro-1-benzothiophen-3-yl)(phenyl)methanone (1) crystallizes in the orthorhombic space group Pna21 (a = 9.2080(4) Å, b = 14.0485(7) Å, c [...] Read more.
The crystal and molecular structures of two 2-aminothiophene derivatives, potential allosteric enhancers at the human A1 adenosine receptor, are reported. (2-Amino-4,5,6,7-tetrahydro-1-benzothiophen-3-yl)(phenyl)methanone (1) crystallizes in the orthorhombic space group Pna21 (a = 9.2080(4) Å, b = 14.0485(7) Å, c = 10.3826(6) Å), and (2-amino-5-ethylthiophen-3-yl)(2-chlorophenyl)methanone (2) crystalizes in the monoclinic P21/c space group with unit cell parameters a = 10.6092(8) Å, b = 10.8355(8) Å, c = 11.1346(9) Å, β = 98.643(6)Å. In both molecules the intramolecular N–H···O=C hydrogen bonds close six-membered planar rings and significantly influence the molecular conformation. Intermolecular N–H···O bonds connect the molecules in infinite chains along a in case of 1, and along b in 2; in each case the appropriate unit cell axis is approximately 10 Å long. Full article
Show Figures

Figure 1

382 KiB  
Review
Magnetic and Electric Properties of Organic Conductors Probed by 13C-NMR Using Selective-Site Substituted Molecules
by Shinji Hirose, Masaki Misawa and Atsushi Kawamoto
Crystals 2012, 2(3), 1034-1057; https://doi.org/10.3390/cryst2031034 - 27 Jul 2012
Cited by 11 | Viewed by 7012
Abstract
Quasi-One and quasi-two dimensional organic conductors consisting of TTF derivatives such as BEDT-TTF (bis-(ethylene-dithio)-tetra-thia-fulvalene) and TMTCF (C = S; TMTTF: tetra-methyl-tetra-thia-fulvalene, C = Se; TMTSF: tetra-methyl-tetra-selena-fulvalene) have been well investigated in condensed matter physics because of interest in the emerging [...] Read more.
Quasi-One and quasi-two dimensional organic conductors consisting of TTF derivatives such as BEDT-TTF (bis-(ethylene-dithio)-tetra-thia-fulvalene) and TMTCF (C = S; TMTTF: tetra-methyl-tetra-thia-fulvalene, C = Se; TMTSF: tetra-methyl-tetra-selena-fulvalene) have been well investigated in condensed matter physics because of interest in the emerging electric and magnetic properties, such as the spin density wave, charge order, superconductivity, anti-ferromagnetism, and so on. To probe the electronic state, nuclear magnetic resonance (NMR) is one of the most powerful tools as the microscopic magnetometer. A number of 13C-NMR studies have been performed of the double-site central 13C=13C bond substituted molecules. However, problems with the coupled spin system of 13C=13C complicated the interpretation for observations on NMR. Therefore, single-site 13C-enriched molecules are desired. We summarize the problem of Pake doublet and the preparation of the single-site 13C-susbstituted BEDT-TTF and TMTCF molecules. We also demonstrate the superiority of 13C-NMR of the single-site 13C-susbstituted molecule utilizing the hyperfine coupling tensor. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

2719 KiB  
Article
Halogen Interactions in 2,4,5-Tribromoimidazolium Salts
by Carmen Froschauer, Volker Kahlenberg, Gerhard Laus and Herwig Schottenberger
Crystals 2012, 2(3), 1017-1033; https://doi.org/10.3390/cryst2031017 - 27 Jul 2012
Cited by 7 | Viewed by 7039
Abstract
The crystal structures of 2,4,5-tribromo-1-(prop-2-ynyl)imidazole and seven new 1,3-dialkyl-2,4,5-tribromoimidazolium salts (R1 = propenyl, propynyl, dibromopropenyl; R2 = Me, Et) with halogen-containing anions (tetrafluoroborate, hexafluorophosphate, triflimide) were determined. The structures revealed halogen...halogen and anion...π interactions. Contacts of the type Br...Br, Br...F, [...] Read more.
The crystal structures of 2,4,5-tribromo-1-(prop-2-ynyl)imidazole and seven new 1,3-dialkyl-2,4,5-tribromoimidazolium salts (R1 = propenyl, propynyl, dibromopropenyl; R2 = Me, Et) with halogen-containing anions (tetrafluoroborate, hexafluorophosphate, triflimide) were determined. The structures revealed halogen...halogen and anion...π interactions. Contacts of the type Br...Br, Br...F, Br...O, Br...N, F...F, H...Br, H...F, F...π and O...π were identified. Specific interactions were quantified by Hirshfeld surface analysis. Full article
Show Figures

Graphical abstract

508 KiB  
Review
Theoretical Studies on Phase Transitions in Quasi-One-Dimensional Molecular Conductors
by Hideo Yoshioka, Yuichi Otsuka and Hitoshi Seo
Crystals 2012, 2(3), 996-1016; https://doi.org/10.3390/cryst2030996 - 19 Jul 2012
Cited by 14 | Viewed by 7794
Abstract
A review is given for recent theoretical studies on phase transitions in quasi-one-dimensional molecular conductors with a quarter-filled band. By lowering temperature, charge transfer salts exhibit a variety of transitions accompanying symmetry breaking, such as charge ordering, lattice dimerization, antiferromagnetic transition, spin-Peierls distortion, [...] Read more.
A review is given for recent theoretical studies on phase transitions in quasi-one-dimensional molecular conductors with a quarter-filled band. By lowering temperature, charge transfer salts exhibit a variety of transitions accompanying symmetry breaking, such as charge ordering, lattice dimerization, antiferromagnetic transition, spin-Peierls distortion, and so on. Analyses on microscopic quasi-one-dimensional models provide their systematic understandings, by the complementary use of different analytical and numerical techniques; they can reproduce finite-temperature phase transitions, whose results can be directly compared with experiments and give feedbacks to material design. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

441 KiB  
Review
Paramagnetic Metal—Antiferromagnetic Insulator Transition in π-d System λ-BETS2FeCl4, BETS = Bis(ethylenedithio)tetraselenafulvalene
by Hiroshi Akiba, Kazuo Shimada, Naoya Tajima, Koji Kajita and Yutaka Nishio
Crystals 2012, 2(3), 984-995; https://doi.org/10.3390/cryst2030984 - 17 Jul 2012
Cited by 5 | Viewed by 6695
Abstract
Quasi-two-dimensional organic conductor λ-BETS2FeCl4 (BETS = bis(ethylenedithio)tetraselenafulvalene) transforms from a paramagnetic metal (PM) to an antiferromagnetic insulator (AFI) at a transition temperature, TMI, of 8.3 K under zero magnetic field. To understand the mechanism of this PM-AFI phase [...] Read more.
Quasi-two-dimensional organic conductor λ-BETS2FeCl4 (BETS = bis(ethylenedithio)tetraselenafulvalene) transforms from a paramagnetic metal (PM) to an antiferromagnetic insulator (AFI) at a transition temperature, TMI, of 8.3 K under zero magnetic field. To understand the mechanism of this PM-AFI phase transition, we studied the thermodynamic properties of λ-BETS2FeCl4. We observed, below TMI, a six-level Schottky hump in its specific heat and a broad shoulder in its magnetic susceptibility. Just below the transition temperature TMI, about 80% of 3d spin degree of freedom is sustained. These temperature dependences clarify that π and 3d spins do not cooperatively form the AF order at TMI. In λ-BETS2FexGa1−xCl4 system, the increasing Fe 3d spin density enhances the internal magnetic field caused by π spin antiferromagnetic (AF) ordering, although the 3d spin itself maintains large entropy against the AF ordering. It was confirmed that the Fe 3d spin provided favorable conditions for this mysterious PM-AFI phase transition in the π electron system. We propose that this phase transition originates from the magnetic anisotropy introduced by the π-d interaction, which suppressed the low dimensional fluctuation in the π spin system. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

876 KiB  
Article
1,5-Diaminopentane As A Structure-Directing Agent for Zincophosphate Networks: Zn3(PO4)2(C5H14N2)2·3H2O and C5H16N2·Zn3(PO4)2(HPO4)·H2O
by William T.A. Harrison and William R. Currie
Crystals 2012, 2(3), 974-983; https://doi.org/10.3390/cryst2030974 - 16 Jul 2012
Cited by 6 | Viewed by 6966
Abstract
The crystal structures of two zincophosphate networks prepared in the presence of 1,5-diaminopentane (dap) are described. In Zn3(PO4)2(C5H14N2)2·3H2O (1) the dap forms Zn–N coordinate bonds [...] Read more.
The crystal structures of two zincophosphate networks prepared in the presence of 1,5-diaminopentane (dap) are described. In Zn3(PO4)2(C5H14N2)2·3H2O (1) the dap forms Zn–N coordinate bonds to generate an unusual three-dimensional “hybrid” framework constructed from ZnO3N, ZnO2N2 and PO4 tetrahedra with three different types of elongated channels occupied by water molecules. In C5H16N2·Zn3(PO4)2(HPO4)·H2O; (2) the doubly-protonated H2dap acts in a more typical way to template double layers of vertex-sharing ZnO4, PO4 and HPO4 tetrahedra incorporating 10-rings and interacts with the inorganic component via N–H O hydrogen bonds. Crystal data: 1 (C10H34N4O11P2Zn3), Mr = 644.46, monoclinic, C2 (No. 4), Z = 4, a = 25.302 (7) Å, b = 4.9327 (13) Å, c = 19.808 (6) Å, b = 107.377 (8)°, V = 2359.4 (12) Å3, R(F) = 0.054, wR(F2) = 0.139. 2 (C5H19N2O13P3Zn3), Mr = 604.24, monoclinic, P21/c (No. 14), Z = 4, a = 11.3275 (15) Å, b = 8.3235 (11) Å, c = 18.588 (2) Å, b = 96.979 (3)°, V = 1739.6 (4) Å3, R(F) = 0.056, wR(F2) = 0.119. Full article
Show Figures

Figure 1

210 KiB  
Communication
Simple and Efficient One-Pot Synthesis, Spectroscopic Characterization and Crystal Structure of Methyl 5-(4-Chlorobenzoyloxy)-1-phenyl-1H-pyrazole-3-carboxylate
by Imtiaz Khan and Jonathan M. White
Crystals 2012, 2(3), 967-973; https://doi.org/10.3390/cryst2030967 - 16 Jul 2012
Cited by 7 | Viewed by 5192
Abstract
A facile one-pot synthesis of methyl 5-(4-chlorobenzoyloxy)-1-phenyl-1H-pyrazole-3-carboxylate (4) is described. The title compound was efficiently synthesized by the reaction of phenyl hydrazine, dimethyl acetylenedicarboxylate and 4-chlorobenzoyl chloride in dichloromethane under reflux in good yield. The structure of the target compound was [...] Read more.
A facile one-pot synthesis of methyl 5-(4-chlorobenzoyloxy)-1-phenyl-1H-pyrazole-3-carboxylate (4) is described. The title compound was efficiently synthesized by the reaction of phenyl hydrazine, dimethyl acetylenedicarboxylate and 4-chlorobenzoyl chloride in dichloromethane under reflux in good yield. The structure of the target compound was deduced by modern spectroscopic and analytical techniques and unequivocally confirmed by a single crystal X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P 21 21 21 with cell parameters a = 6.6491(3) Å, b = 7.9627(6) Å, c = 30.621(5) Å, α = β = γ = 90° and Z = 4. The crystal packing of the compound (4) is stabilized by an offset π-stacking between the planar benzoyl-substituted diazole moieties. Full article
Show Figures

Figure 1

1414 KiB  
Article
Preparation and Crystal Structure of Diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II)
by Manuel Joas, Thomas M. Klapötke and Jörg Stierstorfer
Crystals 2012, 2(3), 958-966; https://doi.org/10.3390/cryst2030958 - 10 Jul 2012
Cited by 9 | Viewed by 7694
Abstract
The crystal structure of the coordination polymer diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II) was determined by X-ray diffraction. The copper atoms are connected to chains over the bridging 5,5'-bistetrazolato ligand. The energetic properties of the [...] Read more.
The crystal structure of the coordination polymer diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II) was determined by X-ray diffraction. The copper atoms are connected to chains over the bridging 5,5'-bistetrazolato ligand. The energetic properties of the compound were investigated, such as thermal behavior and sensitivities (shock, friction, electrical spark). Full article
Show Figures

Figure 1

636 KiB  
Article
Metallic One-Dimensional Conductors Composed of Axially Ligated (Phthalocyanato)CoIII with Supramolecular Cations of A(EtOH)4 (A = Na and K)
by Yasuhiro Tanaka, Manabu Ishikawa, Naoko Watanabe, Yukihiro Takahashi, Toshio Naito and Tamotsu Inabe
Crystals 2012, 2(3), 946-957; https://doi.org/10.3390/cryst2030946 - 10 Jul 2012
Cited by 2 | Viewed by 5796
Abstract
Electrolysis of Na and K salts of the anion dicyano(phthalocyaninato)cobalt(III) (Co(Pc)(CN)2) in ethanol yields one-dimensional partially oxidized salts of A[Co(Pc)(CN)2]2.4(EtOH) (A = Na and K). The cationic component is the supramolecular cation [A(EtOH)4]+, [...] Read more.
Electrolysis of Na and K salts of the anion dicyano(phthalocyaninato)cobalt(III) (Co(Pc)(CN)2) in ethanol yields one-dimensional partially oxidized salts of A[Co(Pc)(CN)2]2.4(EtOH) (A = Na and K). The cationic component is the supramolecular cation [A(EtOH)4]+, which forms hydrogen bonds with the CN ligands of the Co(Pc)(CN)2 units. The crystal shows metallic conductivity, in contrast to the thermally activated conductivity observed in the isomorphous tetraphenylphosphonium (TPP) salt of TPP[Co(Pc)(CN)2]2. Since the π-π interactions in these isomorphous crystals are nearly the same, the distinctive behavior of the Na and K salts may be attributed to the difference in the degree of charge disproportionation in these crystals. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

615 KiB  
Article
One-Pot Synthesis of Cu(II) Complex with Partially Oxidized TTF Moieties
by Hiroyuki Nishikawa, Ryosuke Kitabatake, Kiyotaka Mitsumoto, Takuya Shiga and Hiroki Oshio
Crystals 2012, 2(3), 935-945; https://doi.org/10.3390/cryst2030935 - 10 Jul 2012
Cited by 3 | Viewed by 6465
Abstract
The one-pot synthesis of a Cu(II) complex with partially oxidized tetrathiafulvalene (TTF) moieties in its capping MT-Hsae-TTF ligands, [CuII(MT-sae-TTF)2] [CuICl2] was realized by the simultaneous occurrence of Cu(II) complexation and CuIICl2 mediated [...] Read more.
The one-pot synthesis of a Cu(II) complex with partially oxidized tetrathiafulvalene (TTF) moieties in its capping MT-Hsae-TTF ligands, [CuII(MT-sae-TTF)2] [CuICl2] was realized by the simultaneous occurrence of Cu(II) complexation and CuIICl2 mediated oxidation of TTF moieties. The crystal structure was composed of one-dimensional columns formed by partially oxidized TTF moieties and thus the cation radical salt showed relatively high electrical conductivity. Tight binding band structure calculations indicated the existence of a Peierls gap due to the tetramerization of the TTF moieties in the one-dimensional stacking column at room temperature, which is consistent with the semiconducting behavior of this salt. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Graphical abstract

795 KiB  
Review
Vibrational Spectra of β″-Type BEDT-TTF Salts: Relationship between Conducting Property, Time-Averaged Site Charge and Inter-Molecular Distance
by Takashi Yamamoto
Crystals 2012, 2(3), 893-934; https://doi.org/10.3390/cryst2030893 - 06 Jul 2012
Cited by 12 | Viewed by 6594
Abstract
The relationship between the conducting behavior and the degree of charge fluctuation in the β″-type BEDT-TTF salts is reviewed from the standpoints of vibrational spectroscopy and crystal structure. A group of β″-type ET salts demonstrates the best model compounds for achieving [...] Read more.
The relationship between the conducting behavior and the degree of charge fluctuation in the β″-type BEDT-TTF salts is reviewed from the standpoints of vibrational spectroscopy and crystal structure. A group of β″-type ET salts demonstrates the best model compounds for achieving the above relationship because the two-dimensional structure is simple and great diversity in conducting behavior is realized under ambient pressure. After describing the requirement for the model compound, the methodology for analyzing the results of the vibrational spectra is presented. Vibrational spectroscopy provides the time-averaged molecular charge, the charge distribution in the two-dimensional layer, and the inter-molecular interactions, etc. The experimental results applied to 2/3-filled and 3/4-filled β″-type ET salts are reported. These experimental results suggest that the conducting property, the difference in the time-averaged molecular charges between the ionic and neutral-like sites, the alternation in the inter-molecular distances and the energy levels in the charge distributions are relevant to one another. The difference in the time-averaged molecular charges, ∆ρ, is a useful criterion for indicating conducting behavior. All superconductors presented in this review are characterized as small but finite ∆ρ. Full article
(This article belongs to the Special Issue Molecular Conductors)
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop