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Inorganics
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Metal Complexes with N-donor Ligands
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Metal Complexes with N-donor Ligands

A special issue of Inorganics (ISSN 2304-6740). This special issue belongs to the section "Coordination Chemistry".

Deadline for manuscript submissions: closed (31 May 2023) | Viewed by 29178

Special Issue Editor

Dr. László Kótai

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Guest Editor
Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
Interests: coordination chemistry; redox reactions; inorganic synthesis; ammines; oxometallate salts; pyridine complexes; urea complexes; thermal analysis; spectroscopy; structure determination
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues, 

Complexes of metals with N-base ligands like ammonia, amines, urea derivatives, or N-heterocycles are a highly important class of compounds in chemistry, biochemistry, and material science. Many enzymes comprise these kinds of metal complexes. Coordination chemistry of metal complexes with N-bases, including structural features and ligand–central atom or ligand–anion interactions in the solid or solution phase, offers facile routes to prepare and study such industrially important materials. For instance, the interaction of oxidizing anions with reducing N-base ligands within these complex compounds can result in mixed oxides in nanometric size that can be used as catalysts in various technologically important reactions such as CO2 reduction, Fischer–Tropsch synthesis, CO oxidation, etc.   

This Special Issue of Inorganics highlights the chemistry of metal complexes containing N-base ligands (ammonia, amines, urea and pyridine, or other N- heterocycle derivatives) and their relevance to science and industry.  

Dr. László Kótai
Guest Editor

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Keywords

  • ammonia complexes
  • pyridine complexes
  • heterocyclic N-base complexes
  • transition and non-transition metal complexes
  • complex structures
  • redox reactions of ligands in complexes

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Published Papers (13 papers)

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Editorial

Jump to: Research, Review

5 pages, 201 KiB  
Editorial
Metal Complexes with N-donor Ligands
by László Kótai
Inorganics 2024, 12(5), 130; https://doi.org/10.3390/inorganics12050130 - 29 Apr 2024
Viewed by 1767
Abstract
Complexes of transition and non-transition metals with a wide variety of N-donor ligands (like ammonia, amines, urea derivatives, Schiff bases, or N-heterocycles) comprise a highly important class of compounds in chemistry, biochemistry, material science, and the chemical industry [...] Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)

Research

Jump to: Editorial, Review

15 pages, 2356 KiB  
Article
Reactivity of N-Heterocyclic Stannylenes: Oxidative Addition of Chalcogen Elements to a Chiral NH-Sn System
by Kerry R. Flanagan, James D. Parish, Gabriele Kociok-Köhn and Andrew L. Johnson
Inorganics 2023, 11(8), 318; https://doi.org/10.3390/inorganics11080318 - 27 Jul 2023
Cited by 1 | Viewed by 1578
Abstract
The reactivity of the racemic N-heterocyclic stannylene [{MeHCN(tBu)}Sn] (1) with the chalcogenide elements O2, S, Se, and Te has been investigated. In the case of the reaction of 1 with molecular oxygen, the cyclic tristannoxane complex [{MeHCN( [...] Read more.
The reactivity of the racemic N-heterocyclic stannylene [{MeHCN(tBu)}Sn] (1) with the chalcogenide elements O2, S, Se, and Te has been investigated. In the case of the reaction of 1 with molecular oxygen, the cyclic tristannoxane complex [{MeHCN(tBu)}2Sn(μ-O)]3 (3) was isolated and characterised. NMR studies (1H, 13C, and 119Sn) show the formation of D3- and C2- symmetric assemblies. The reaction of 1 with S, Se, and Te, respectively, yielded the cyclo-distannachalcogenide complexes, [{MeHCN(tBu)}2Sn(μ-E)]3 (4: E = S, 5: E = Se, 6: E = Te), again with multinuclear NMR studies proving the formation of C2- and Cs-symmetric assemblies. Single crystal X-ray diffraction studies have been used to elucidate the molecular structures of the products of oxidative addition, 3, 4, 5, and 6. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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21 pages, 10395 KiB  
Article
Iron(III)-Complexes with N-Phenylpyrazole-Based Ligands
by Tanja Hirschhausen, Lorena Fritsch, Franziska Lux, Jakob Steube, Roland Schoch, Adam Neuba, Hans Egold and Matthias Bauer
Inorganics 2023, 11(7), 282; https://doi.org/10.3390/inorganics11070282 - 29 Jun 2023
Cited by 2 | Viewed by 2014
Abstract
The use of iron as a replacement for noble metals in photochemical and photophysical applications is challenging due to the typically fast deactivation of short-lived catalytically active states. Recent success of a cyclometalated iron(III) complex utilizing a bis-tridentate ligand motif inspired the use [...] Read more.
The use of iron as a replacement for noble metals in photochemical and photophysical applications is challenging due to the typically fast deactivation of short-lived catalytically active states. Recent success of a cyclometalated iron(III) complex utilizing a bis-tridentate ligand motif inspired the use of phenyl-1H-pyrazole as a bidentate ligand. Five complexes using the tris(1-phenylpyrazolato-N,C2)iron(III) complex scaffold are presented. In addition to the parent complex, four derivatives with functionalization in the meta-position of the phenyl ring are thoroughly investigated by single crystal diffractometry, UV-Vis-spectroscopy, and cyclic voltammetry. Advanced X-ray spectroscopy in the form of X-ray absorption and emission spectroscopy allows unique insights into the electronic structure as well as DFT calculations. The ligand design leads to overlapping MLCT and LMCT absorption bands, and emissive behavior is suppressed by low-lying MC states. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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Graphical abstract

27 pages, 4485 KiB  
Article
Copper Complexes of Silicon Pyridine-2-olates RSi(pyO)3 (R = Me, Ph, Bn, Allyl) and Ph2Si(pyO)2
by Anne Seidel, Robert Gericke, Erica Brendler and Jörg Wagler
Inorganics 2023, 11(1), 2; https://doi.org/10.3390/inorganics11010002 - 21 Dec 2022
Cited by 4 | Viewed by 1942
Abstract
The organosilicon pyridine-2-olates 1a–1d (RSi(pyO)3, R = Me (a), Ph (b), Bn (c), Allyl (d); pyO = pyridine-2-olate) may serve as tripodal ligands toward CuCl with formation of complexes [...] Read more.
The organosilicon pyridine-2-olates 1a–1d (RSi(pyO)3, R = Me (a), Ph (b), Bn (c), Allyl (d); pyO = pyridine-2-olate) may serve as tripodal ligands toward CuCl with formation of complexes of the type RSi(μ2-pyO)3CuCl (2a–2d). In addition, for R = Allyl, formation of the more stable isomer 2d′ (κO-pyO)Si(μ2-pyO)2(μ2-Allyl)CuCl was observed. In the presence of dry air (as a source of oxygen), reactions of 1a–1d and CuCl afforded Cu(II) complexes RSi(μ2-pyO)4CuCl (3a–3d); 3a–3c in good yield, and 3d only as a side product. Reaction of Ph2Si(pyO)2 (4) and CuCl in equimolar ratio afforded, depending on reaction conditions, a series of (CuCl)n-ladder-type oligonuclear Cu(I) complexes Ph2Si(μ2-pyO)2(CuCl)n(μ2-pyO)2SiPh2 (n = 2 (52), 3 (53), 4 (54)). In all of the above compounds, the pyO group is Si–O bound and, in the case of μ2 coordination, Cu–N bound. All new compounds (1c, 1d, 2b, 2c, 2d, 2d′, 3b, 3c, 3d, 52, 53, 54) were characterized by single-crystal X-ray diffraction, and further characterization includes solution 1H, 13C, 29Si NMR spectroscopy (1c, 1d, 2b, 2c, 2d’, 53, 54), solid-state 29Si (2b, 2c, 2d′, 53, 54) and 63Cu NMR spectroscopy (2c, 2d′) as well as computational analyses of the isomerization of the couple 2d, 2d′. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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21 pages, 4731 KiB  
Article
3–(2–Pyridyl)pyrazole Based Luminescent 1D-Coordination Polymers and Polymorphic Complexes of Various Lanthanide Chlorides Including Orange-Emitting Cerium(III)
by Heba Youssef, Alexander E. Sedykh, Jonathan Becker, Ilya V. Taydakov and Klaus Müller-Buschbaum
Inorganics 2022, 10(12), 254; https://doi.org/10.3390/inorganics10120254 - 10 Dec 2022
Cited by 3 | Viewed by 2025
Abstract
A series of 18 lanthanide-containing 1D-coordination polymers 1∞[Ln2(2–PyPzH)4Cl6], Ln = La, Nd, Sm, dinuclear polymorphic complexes α–, β–[Ln2(2–PyPzH)4Cl6], Ln = Sm, Eu, Gd, α–[Tb2(2–PyPzH)4Cl6 [...] Read more.
A series of 18 lanthanide-containing 1D-coordination polymers 1∞[Ln2(2–PyPzH)4Cl6], Ln = La, Nd, Sm, dinuclear polymorphic complexes α–, β–[Ln2(2–PyPzH)4Cl6], Ln = Sm, Eu, Gd, α–[Tb2(2–PyPzH)4Cl6], and [Gd2(2–PyPzH)3(2–PyPz)Cl5], mononuclear complexes [Ce(2–PyPzH)3Cl3], [Ln(2–PyPzH)2Cl3], Ln = Tb, Dy, Ho, and Er, and salt-like complexes [Gd3(2–PyPzH)8Cl8]Cl and [PyH][Tb(2–PyPzH)2Cl4] were obtained from the reaction of the respective lanthanide chloride with the 3–(2–pyridyl)pyrazole (2–PyPzH) ligand at different temperatures. An antenna effect through ligand-to-metal energy transfer was observed for several products, leading to the highest luminescence efficiency displayed by a quantum yield of 92% in [Tb(2–PyPzH)2Cl3]. The Ce3+ ion in the complex [Ce(2–PyPzH)3Cl3] exhibits a bright and orange 5d-based broadband emission with a maximum at around 600 nm, marking an example of a strong reduction of the 5d-excited states of Ce(III). The absorption spectroscopy shows ion-specific 4f–4f transitions, which can be assigned to Nd3+, Sm3+, Eu3+, Dy3+, Ho3+, and Er3+ in a wide spectral range from UV–VIS to the NIR region. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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10 pages, 2560 KiB  
Article
Iridium(III) and Rhodium(III) Half-Sandwich Coordination Compounds with 11H-Indeno[1,2-b]quinoxalin-11-one Oxime: A Case of Spontaneous Resolution of Rh(III) Complex
by Vladislava V. Matveevskaya, Dmitry I. Pavlov and Andrei S. Potapov
Inorganics 2022, 10(11), 179; https://doi.org/10.3390/inorganics10110179 - 25 Oct 2022
Cited by 3 | Viewed by 1981
Abstract
Two half-sandwich iridium(III) and rhodium(III) complexes with 11H-indeno[1,2-b]quinoxalin-11-one oxime (IQ-1) ligand were prepared by the reaction of the proligand with [M(Cp*)Cl2]2 (M = Ir, Rh) dimers. The reaction between IQ-1 and [Ir(Cp*)Cl2]2 in methanol gave [...] Read more.
Two half-sandwich iridium(III) and rhodium(III) complexes with 11H-indeno[1,2-b]quinoxalin-11-one oxime (IQ-1) ligand were prepared by the reaction of the proligand with [M(Cp*)Cl2]2 (M = Ir, Rh) dimers. The reaction between IQ-1 and [Ir(Cp*)Cl2]2 in methanol gave the complex [Ir(Cp*)(IQ-1)Cl] (1), which crystallized in a centrosymmetric space group as a true racemate. Whereas complex [Rh(Cp*)(IQ-1)Cl] (2) in the form of a racemic conglomerate was obtained by the reaction of [Rh(Cp*)Cl2]2 and IQ-1 in methanol. The crystal structures of complexes 1 and 2 (R and S enantiomers) were determined by X-ray diffraction analysis, and the structural features were compared in order to understand the structural factors leading to the spontaneous enantiomer resolution of the rhodium(III) complex. In the crystal packing of 1, intermolecular C–H···C contacts between a pair of enantiomers link the molecules into centrosymmetric dimers and lead to the formation of heterochiral crystals of 1. In contrast, the intramolecular contacts CH···Cl and CH···C in complex 2 bind all three ligands around the chiral Rh(III) metal center. In addition, a combination of intermolecular CH···O and CH···C contacts leads to the formation of a homochiral supramolecular structure. These interactions altogether reinforce the spontaneous resolution in complex 2. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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13 pages, 3525 KiB  
Article
Synthesis, Structures, and Photoluminescence of Two Novel Zinc(II) Compounds Containing 2-Acetylpyridine-aminoguanidine
by Mirjana M. Radanović, Ljiljana S. Vojinović-Ješić, Miodrag G. Jelić, Elias Sakellis, Berta Barta Holló, Vukadin M. Leovac and Marko V. Rodić
Inorganics 2022, 10(10), 147; https://doi.org/10.3390/inorganics10100147 - 20 Sep 2022
Cited by 3 | Viewed by 1613
Abstract
In the reaction of zinc(II) sulfate and the chloride salt of 2-acetylpyridine-aminoguanidine, two types of complex were obtained, i.e., [Zn(H2O)6](H2L)2(SO4)3·3H2O and [Zn(L)H2O(SO4)]·H2O, depending [...] Read more.
In the reaction of zinc(II) sulfate and the chloride salt of 2-acetylpyridine-aminoguanidine, two types of complex were obtained, i.e., [Zn(H2O)6](H2L)2(SO4)3·3H2O and [Zn(L)H2O(SO4)]·H2O, depending on the presence of LiOAc as the deprotonating agent. The physicochemical, structural, and photoluminescence properties of the complexes were examined. In the first complex, obtained in the absence of LiOAc, the Schiff base had the role of a counter-ion in its doubly protonated form, while in the presence of LiOAc, upon deprotonation, coordination takes place, and thus the Schiff base acts as a tridentate N3 ligand. In the latter complex, the ligand is coordinated through pyridine, azomethine, and the imino nitrogen of the aminoguanidine residue, leading to formation of two fused five-membered chelate rings. Both the examined complexes, as well as the ligand itself, show high photoluminescence. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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16 pages, 3751 KiB  
Article
Structure and Vibrational Spectra of Pyridine Solvated Solid Bis(Pyridine)silver(I) Perchlorate, [Agpy2ClO4]·0.5py
by Nóra V. May, Niloofar Bayat, Kende Attila Béres, Petra Bombicz, Vladimir M. Petruševski, György Lendvay, Attila Farkas and László Kótai
Inorganics 2022, 10(9), 123; https://doi.org/10.3390/inorganics10090123 - 25 Aug 2022
Cited by 3 | Viewed by 2176
Abstract
A hemipyridine solvate of bis(pyridine)silver(I) perchlorate, [Agpy2ClO4]·0.5py (compound 1) was prepared and characterized by single crystal X-ray analysis and vibrational spectroscopy (R and low-temperature Raman). Compound 1 was prepared via the trituration of [Agpy2ClO4] [...] Read more.
A hemipyridine solvate of bis(pyridine)silver(I) perchlorate, [Agpy2ClO4]·0.5py (compound 1) was prepared and characterized by single crystal X-ray analysis and vibrational spectroscopy (R and low-temperature Raman). Compound 1 was prepared via the trituration of [Agpy2ClO4] and 4[Agpy2ClO4]·[Agpy4]ClO4 (as the source of the solvate pyridine) in a mixed solvent of acetone:benzene =1:1 (v = v) at room temperature. The monoclinic crystals of compound 1 were found to be isomorphic with the analogous permanganate complex (a = 19.1093(16) Å, b = 7.7016(8) Å, c = 20.6915(19) Å, β = 105.515(7)°; space group: C2/c). Two [Agpy2]+ cations formed a dimeric unit [Agpy2ClO4]2, and each silver ion was connected to two ClO4− anions via oxygen atoms. The Ag∙∙∙Ag distance was 3.3873(5) Å, the perchlorate ions were coordinated to silver ions, and the Ag∙∙∙O distances were 2.840(2) Å and 2.8749(16) Å in the centrosymmetric rectangle of Ag-O-Ag-O. The stoichiometric ratio of the monomer [Agpy2ClO4] and the solvent pyridine was 1:0.5. The guest pyridine occupied 527.2 Å3, which was 18.0% of the volume of the unit cell. There was no additional residual solvent-accessible void in the crystal lattice. The solvate pyridine was connected via its a-CH to one of the O atoms of the perchlorate anion. Correlation analysis, as well as IR and low-temperature Raman studies, were performed to assign all perchlorate and pyridine vibrational modes. The solvate and coordinated pyridine bands in the IR and Raman spectra were not distinguishable. A perchlorate contribution via Ag-O coordination to low-frequency Raman bands was also assigned. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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13 pages, 1202 KiB  
Article
Investigations on the Spin States of Two Mononuclear Iron(II) Complexes Based on N-Donor Tridentate Schiff Base Ligands Derived from Pyridine-2,6-Dicarboxaldehyde
by Yosef Bayeh, Nithin Suryadevara, Sören Schlittenhardt, Róbert Gyepes, Assefa Sergawie, Peter Hrobárik, Wolfgang Linert, Mario Ruben and Madhu Thomas
Inorganics 2022, 10(7), 98; https://doi.org/10.3390/inorganics10070098 - 8 Jul 2022
Cited by 3 | Viewed by 2550
Abstract
Iron(II)-Schiff base complexes are a well-studied class of spin-crossover (SCO) active species due to their ability to interconvert between a paramagnetic high spin-state (HS, S = 2, 5T2) and a diamagnetic low spin-state (LS, S = 0, 1A1 [...] Read more.
Iron(II)-Schiff base complexes are a well-studied class of spin-crossover (SCO) active species due to their ability to interconvert between a paramagnetic high spin-state (HS, S = 2, 5T2) and a diamagnetic low spin-state (LS, S = 0, 1A1) by external stimuli under an appropriate ligand field. We have synthesized two mononuclear FeII complexes, viz., [Fe(L1)2](ClO4)2.CH3OH (1) and [Fe(L2)2](ClO4)2.2CH3CN (2), from two N6–coordinating tridentate Schiff bases derived from 2,6-bis[(benzylimino)methyl]pyridine. The complexes have been characterized by elemental analysis, electrospray ionization–mass spectrometry (ESI-MS), Fourier-transform infrared spectroscopy (FTIR), solution state nuclear magnetic resonance spectroscopy, 1H and 13C NMR (both theoretically and experimentally), single-crystal diffraction and magnetic susceptibility studies. The structural, spectroscopic and magnetic investigations revealed that 1 and 2 are with Fe–N6 distorted octahedral coordination geometry and remain locked in LS state throughout the measured temperature range from 5–350 K. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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19 pages, 5831 KiB  
Article
Synthesis, Physicochemical, Thermal and Antioxidative Properties of Zn(II) Coordination Compounds with Pyrazole-Type Ligand
by Berta Barta Holló, Mirjana M. Radanović, Marko V. Rodić, Sanja Krstić, Željko K. Jaćimović and Ljiljana S. Vojinović Ješić
Inorganics 2022, 10(2), 20; https://doi.org/10.3390/inorganics10020020 - 10 Feb 2022
Cited by 4 | Viewed by 2492
Abstract
The reactions of pyrazole derivative, i.e., ethyl-5-amino-1-methyl-1H-pyrazole-4-carboxylate (L) with zinc halogenides in methanolic solution and zinc nitrate and zinc acetate in acetonic solution are described. The formulae of synthesized compounds are ZnL2Cl2 (1), [ZnL [...] Read more.
The reactions of pyrazole derivative, i.e., ethyl-5-amino-1-methyl-1H-pyrazole-4-carboxylate (L) with zinc halogenides in methanolic solution and zinc nitrate and zinc acetate in acetonic solution are described. The formulae of synthesized compounds are ZnL2Cl2 (1), [ZnL2Br2] (2), ZnL2I2·0.5MeOH (3), [Zn(L)2(H2O)4](NO3)2 (4), and {ZnL(OAc)2}2 (5). Two complexes are obtained in form of single crystals: [ZnL2Br2] (2) and [Zn(L)2(H2O)4](NO3)2 (4). Their crystal and molecular structure were determined by single-crystal X-ray structure analysis. The FTIR spectra of compounds prove the complex formation with all five zinc salts. The complexes are characterized by conductometric and thermoanalytical measurements, and their antioxidative activity was also tested by the scavenging effect on the DPPH radical. Conductometric results, solvolytic stability, and antioxidative activity of the compounds are in correlation. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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22 pages, 5372 KiB  
Article
Multi-Centered Solid-Phase Quasi-Intramolecular Redox Reactions of [(Chlorido)Pentaamminecobalt(III)] Permanganate—An Easy Route to Prepare Phase Pure CoMn2O4 Spinel
by Fernanda Paiva Franguelli, Éva Kováts, Zsuzsanna Czégény, Laura Bereczki, Vladimir M. Petruševski, Berta Barta Holló, Kende Attila Béres, Attila Farkas, Imre Miklós Szilágyi and László Kótai
Inorganics 2022, 10(2), 18; https://doi.org/10.3390/inorganics10020018 - 4 Feb 2022
Cited by 12 | Viewed by 3166
Abstract
We synthesized and structurally characterized the previously unknown [Co(NH3)5Cl](MnO4)2 complex as the precursor of CoMn2O4. The complex was also deuterated, and its FT-IR, far-IR, low-temperature Raman and UV-VIS spectra were measured as [...] Read more.
We synthesized and structurally characterized the previously unknown [Co(NH3)5Cl](MnO4)2 complex as the precursor of CoMn2O4. The complex was also deuterated, and its FT-IR, far-IR, low-temperature Raman and UV-VIS spectra were measured as well. The structure of the complex was solved by single-crystal X-ray diffraction and the 3D-hydrogen bonds were evaluated. The N-H…O-Mn hydrogen bonds act as redox centers to initiate a solid-phase quasi-intramolecular redox reaction even at 120 °C involving the Co(III) centers. The product is an amorphous material, which transforms into [Co(NH3)5Cl]Cl2, NH4NO3, and a todorokite-like solid Co-Mn oxide on treatment with water. The insoluble residue may contain {Mn4IIIMnIV2O12}n4n−, {Mn5IIIMnIVO12}n5n− or {MnIII6O12}n6n− frameworks, which can embed 2 × n (CoII and/or CoIII) cations in their tunnels, respectively, and 4 × n ammonia ligands are coordinated to the cobalt cations. The decomposition intermediates decompose on further heating via a series of redox reactions, forming a solid CoIIMIII2O4 spinel with an average size of 16.8 nm, and gaseous N2, N2O and Cl2. The CoMn2O4 prepared in this reaction has photocatalytic activity in Congo red degradation with UV light. Its activity strongly depends on the synthesis conditions, e.g., Congo red was degraded 9 and 13 times faster in the presence of CoMn2O4 prepared at 550 °C (in air) or 420 °C (under N2), respectively. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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Review

Jump to: Editorial, Research

38 pages, 3801 KiB  
Review
Review on the Chemistry of [M(NH3)n](XO4)m (M = Transition Metal, X = Mn, Tc or Re, n = 1–6, m = 1–3) Ammine Complexes
by Raj Narain Mehrotra
Inorganics 2023, 11(7), 308; https://doi.org/10.3390/inorganics11070308 - 20 Jul 2023
Cited by 6 | Viewed by 2545
Abstract
The preparation of ammine complexes of transition metals having oxidizing anions such as permanganate and perrhenate ions is a great challenge due to possible reactions between ammonia and oxidizing anions during the synthesis of these materials. However, it has an important role in [...] Read more.
The preparation of ammine complexes of transition metals having oxidizing anions such as permanganate and perrhenate ions is a great challenge due to possible reactions between ammonia and oxidizing anions during the synthesis of these materials. However, it has an important role in both the development of new oxidants in organic chemistry and especially in the preparation of mixed-metal oxide catalyst precursors and metal alloys for their controlled temperature decomposition reactions. Therefore, in this paper, synthetic procedures to prepare ammonia complexes of transition metal permanganate, pertechnetate, and perrhenate (the VIIB group tetraoxometallates) salts have been comprehensively reviewed. The available data about these compounds’ structures and spectroscopic properties, including the presence of hydrogen bonds that act as redox reaction centers during thermal decomposition, are given and evaluated in detail. The nature of the thermal decomposition products has also been summarized. The available information about the role of the ammine complexes of transition metal permanganate salts in organic oxidation reactions, such as the oxidation of benzyl alcohols and regeneration of oxo-compounds from oximes and phenylhydrazones, including the kinetics of these processes, has also been collected. Their physical and chemical properties, including the thermal decomposition characteristics of known diammine (Ag(I), Cd, Zn, Cu(II), Ni(II)), triammine (Ag(I)), and simple or mixed ligand tetraammine (Cu(II), Zn, Cd, Ni(II), Co(II), Pt(II), Pd(II), Co(III)), Ru(III), pentaammine (Co(III), Cr(III), Rh(III) and Ir(III)), and hexaammine (Ni(II), Co(III), Cr(III)) complexes of transition metals with tetraoxometallate(VII) anions (M = Mn, Tc and Re), have been summarized. The preparation and properties of some special mixed ligand/anion/cation-containing complexes, such as [Ru(NH3)4(NO)(H2O)](ReO4)2, [Co(NH3)5(H2O)](ReO4)2, [Co(NH3)5X](MnO4)2 (X = Cl, Br), [Co(NH3)6]Cl2(MnO4), [Co(NH3)5ReO4]X2 (X = Cl, NO3, ClO4, ReO4), and K[Co(NH3)6]Cl2(MnO4)2, are also included. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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49 pages, 1620 KiB  
Review
Au(III) Cyclometallated Compounds with 2-Arylpyridines and Their Derivatives or Analogues: 34 Years (1989–2022) of NMR and Single Crystal X-ray Studies
by Leszek Pazderski and Pavel A. Abramov
Inorganics 2023, 11(3), 100; https://doi.org/10.3390/inorganics11030100 - 28 Feb 2023
Cited by 6 | Viewed by 1638
Abstract
A review paper on Au(III) cyclometallated compounds with 2-arylpyridines (2-phenylpyridine, 2-benzylpyridine, 2-benzoylpyridine, 2-phenoxypyridine, 2-phenylsulfanylpyridine, 2-anilinopyridine, 2-(naphth-2-yl)pyridine, 2-(9,9-dialkylfluoren-2-yl)pyridines, 2-(dibenzofuran-4-yl)pyridine, and their derivatives) and their analogues (2-arylquinolines, 1- and 3-arylisoquinolines, 7,8-benzoquinoline), with 113 references. A total of 554 species, containing κ2-N(1),C(6′)*-Au(III), or analogous [...] Read more.
A review paper on Au(III) cyclometallated compounds with 2-arylpyridines (2-phenylpyridine, 2-benzylpyridine, 2-benzoylpyridine, 2-phenoxypyridine, 2-phenylsulfanylpyridine, 2-anilinopyridine, 2-(naphth-2-yl)pyridine, 2-(9,9-dialkylfluoren-2-yl)pyridines, 2-(dibenzofuran-4-yl)pyridine, and their derivatives) and their analogues (2-arylquinolines, 1- and 3-arylisoquinolines, 7,8-benzoquinoline), with 113 references. A total of 554 species, containing κ2-N(1),C(6′)*-Au(III), or analogous moiety (i.e., chelated by nitrogen of the pyridine-like ring and the deprotonated ortho- carbon of the phenyl-like ring) and, thus, possessing a character intermediate between metal complexes and organometallics, studied in the years 1989–2022 by NMR spectroscopy and/or single crystal X-ray diffraction (207 X-ray structures), are described. The compounds for which biological or catalytic activity and the luminescence properties were studied are also quoted. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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