The assembled complex, Fe(NCBH3)2(bpa)2, enclathrating biphenyl has been synthesized, the skeleton of which is a 1D chain. Several 1D chains gather together to form 1D chain sheet. The 1D chain sheet is stacked spirally to form novel spiral assembly. The average Fe-N distances were 2.020(2), 2.083(2), and 2.191(2) Å at 100, 175, and 298 K, respectively, reflecting spin-state change of the iron ion. The assembly showed a stepwise spin-crossover phenomenon. Full article

We attempted synthesis of the hydrogen adsorption material suitable for the fuel cell vehicles (FCEVs). The designed and synthesized Cu₂(3,5-Pyridinedicarboxylate)₂ (=Cu₂PDC₂) metal complex showed an extremely high volumetric uptake density for a physisorption material, even though the specific surface area was only about 1,000 m² g⁻¹. Factors for high uptake properties are considered to be the increased adsorption sites per unit area, the increased adsorption energy, and the optimized design of pore shapes. High hydrogen uptake on volumetric basis is especially effective for FCEV because the tank volume is reduced. It is expected that property prediction using computational simulation and sophisticated analysis at the micro and nano levels will become an indispensable tool in the design of functional materials. Full article

Two-dimensional (2D) grid coordination polymers were prepared by the reaction of 1,4-bis(4-pyridylmethyl)tetrafluorobenzene (bpf) with Cu(NO₃)₂ in the presence of aromatic compounds. Crystal structures of {[Cu(bpf)₂(NO₃)₂]·(biphenyl)₂}_n (1), {[Cu(bpf)₂(NO₃)₂]·(m-C₆H₄(OMe)₂)₂}_n (2), {[Cu(bpf)₂(NO₃)₂]·Ph^tBu}_n (3) and {[Cu(bpf)₂(NO₃)(H₂O)]NO₃·(bpf)_0.5}_n (4) were determined. The grid networks were held together by C–H···O and C–H···F hydrogen bonds via the NO₃⁻ anions and the tetrafluorophenylene rings of bpf, respectively. Biphenyl, m-dimethoxybenzene, t-butylbenzene, and bpf molecules were clathrated in cyclic cavities of the grid networks through arene-perfluoroarene interactions. These coordination networks have remarkable clathration ability for aromatic compounds. Full article

A homochiral metal-organic framework (MOF) based on enantiopure (R)-2,2′-dihydroxy-1,1′-binaphthyl-3,3′-dicarboxylic acid was synthesized. X-ray crystal diffraction studies revealed that the MOF adopts a one-dimensional infinite right-handed helical tubular structure along the a-axis, which serves as a host for the inclusion of guest dimethylformamide (DMF) molecules. Full article

Supramolecular coordination polymers with wavelike structures have been synthesized by self-assembly and their structures analyzed using the sine trigonometric function. Slow evaporation of a methylene chloride-methanol solution of a 1:1 molar mixture of [M(tmhd)₂], where M = Co or Ni, and quinoxaline; a 1:2:1 molar mixture of [M(acac)₂], where M = Co or Ni, 2,2,6,6-tetramethyl-3,5-heptadione and quinoxaline; or a 1:2:1 molar mixture of [Co(acac)₂], dibenzoylmethane, and quinoxaline, yielded the crystalline coordination polymers. In the presence of the nitrogenous base, ligand scrambling occurs yielding the most insoluble product. The synthesis and structures of the following wavelike polymers are reported: trans-[Co(DBM)₂(qox)]_n·nH₂O (2), trans-[Co(tmhd)₂(qox)]_n (3), trans-[Ni(tmhd)₂(qox)]_n (4), where DBM⁻ = dibenzoylmethanate, tmhd⁻ = 2,2,6,6-tetramethyl-3,5-heptadionate, and qox = quinoxaline. The wavelike structures are generated by intramolecular steric interactions and crystal packing forces between the chains. Some of the tert-butyl groups show a two-fold disorder. The sine function, φ = A sin 2πx/λ, where φ = distance (Ǻ) along the polymer backbone, λ = wavelength (Ǻ), A = amplitude (Ǻ), x = distance (Ǻ) along the polymer axis, provides a method to approximate and visualize the polymer structures. Full article

The first MMX-type quasi-one-dimensional (Q1D) Pt chain complex (MMX chain) that contains a mono-protonated diamine as countercation, {o-(H₃NC₆H₄NH₂)}₄[Pt₂(pop)₄I]·H₂O (pop = P₂H₂O₅^2–), was synthesized. According to the crystal structural analysis, –NH₂ group was hydrogen-bonded to either lattice H₂O molecule or –NH₃⁺ group in addition to typical hydrogen bond between –NH₃⁺ group and pop ligand. To control the partial deprotonation of the countercation will be an important method for achieving the high-conductive MMX-chain polymer by the hole doping. Full article

We have studied the loading of two related, similar porous metal-organic frameworks (MOFs) [Cu₂(bdc)₂(dabco)] (1), and [Cu₂(ndc)₂(dabco)] (2) with ferrocene by exposing bulk powder samples to the corresponding vapor. On the basis of powder X-ray diffraction data and molecular dynamics (MD) calculations we propose that each pore can store one ferrocene molecule. Despite the rather pronounced similarity of the two MOFs a quite different behavior is observed, for 1 loading with ferrocene leads to an anisotropic 1% contraction, whereas for 2 no deformation is observed. Mössbauer spectroscopy studies reveal that the Fe oxidation level remains unchanged during the process. Time dependent studies reveal that the diffusion constant governing the loading from the gas-phase for 1 is approximately three times larger than the value for 2. Full article

Reaction of cadmium perchlorate and the prototypical linear bridging ligand 4,4’-bipyridine (4,4’-bipy) in an ethanol/water mixture affords the one-dimensional coordination polymer, [{Cd(m-4,4’-bipy)(4,4’-bipy)₂(H₂O)₂}(ClO₄)₂ × 2 4,4’-bipy × 4.5 H₂O]_n (1). The Cd²⁺ ions adopt an octahedral coordination sphere and are joined into linear chains by 4,4’-bipy via two trans coordination sites. The remaining two trans sites in the equatorial plane carry terminally monodentate-bound 4,4’-bipy ligands, resulting in a molecular antenna arrangement. The two axial sites of each Cd²⁺ ion are occupied by aqua ligands. Compound 1 crystallizes in the non-centrosymmetric, monoclinic space group C2 with three similar, crystallographically independent, cationic coordination polymer strands in the unit cell, which essentially differ only in the conformations of the 4,4’-bipyridyl ligands. Consistent with the similarity of the local coordination environments of the three independent Cd atoms in the structure, ¹¹³Cd MAS NMR spectroscopy reveals a single resonance line at 89 ppm. Full article

The chain polymer [{Cd(μ-X)₂py₂}¹_∞] (X = Cl, Br; py = pyridine) undergoes a fully reversible phase transition between a monoclinic low-temperature and an orthorhombic high-temperature phase. The transformation can be directly monitored in single crystals and can be confirmed for the bulk by powder diffraction. The transition temperature can be adjusted by tuning the composition of the mixed-halide phase: Transition temperatures between 175 K up to the decomposition of the material at ca. 350 K are accessible. Elemental analysis, ion chromatography and site occupancy refinements from single-crystal X-ray diffraction agree with respect to the stoichiometric composition of the samples. Full article

We have prepared some diastereomers of [CuL₂][M₂O₇] (L is 1,2-diaminocyclohexane and its derivatives; M = Cr and W) bimetallic coordination polymers and confirmed their structural similarity and inner electronic states by means of XRD and XAS, respectively. For the first time, we have successfully observed distant vicinal effect of which the chiral source is only chiral organic ligands of [CuL₂]²⁺ moieties (acting as ligand complex), while probe bands for solid state CD spectra are charge transfer (CT) bands of [M₂O₇]²⁻ moieties (achiral complex) with the d⁰ electronic configuration. The new concept (interpretation) of this observation will be important for supramolecular chirality of coordination polymers built by ligand complexes. Full article

The perceptible appearance of biomolecules as prospective building blocks in the architecture of coordination polymers (CPs) and metal-organic frameworks (MOFs) are redolent of their inclusion in the synthon/tecton library of reticular chemistry. In this frame, for the first time a synthetic strategy has been established for amine derivatization in amino acids into 1,2,4-triazoles. A set of novel 1,2,4-triazole derivatized amino acids were introduced as superlative precursors in the design of 1D coordination polymers, 2D chiral helicates and 3D metal-organic frameworks. Applications associated with these compounds are diverse and include gas adsorption-porosity partitioning, soft sacrificial matrix for morphology and phase selective cadmium oxide synthesis, Fe^II spin crossover materials, zinc-b-lactamases inhibitors, logistics for generation of chiral/non-centrosymmetric networks; and thus led to a foundation of a new family of functional CPs and MOFs that are reviewed in this invited contribution. Full article

The reaction of hot (~95 °C) aqueous solutions of Tl₂CO₃ with solid HL (HL = NC-C(=N-OH)-R is a cyanoxime, and R is an electron-withdrawing group; 37 ligands are known up-to-date) leads to crystalline yellow/orange TlL. Similarly, the reaction between AgNO₃ and ML (M = K⁺, Na⁺; L = anion of the monodeprotonated cyanoxime) this time at room temperature in mixed ethanol/aqueous solutions leads to sparingly soluble, colored AgL in high-yield. All synthesized monovalent Tl and Ag complexes were characterized using a variety of spectroscopic methods and X-ray analysis, which revealed the formation of primarily 2D coordination polymers of different complexity. In all cases cyanoxime mono-anions act as bridging ligands. Thallium(I) cyanoximates adopt in most cases a double-stranded motif that is originated from centrosymmetric (TlL)₂ dimers in which two Tl₂O₂ rhombs are fused into infinite “ladder-type” structure. There are very short (3.65–3.85 Å) intermetallic distances in (TlL)_n, which are close to that (3.46 Å) in metallic thallium. This opens the possibility for the electrochemical or chemical generation of mixed valence Tl(I)/Tl(III) polymers that may exhibit electrical conductivity. Synthesized silver(I) compounds demonstrate a very significant (for multiple years!) stability towards visible light. There are three areas of potential practical applications of these unusual complexes: (1) battery-less detectors of UV-radiation, (2) non electrical sensors for gases of industrial importance, (3) antimicrobial additives to light-curable acrylate polymeric glues, fillers and adhesives used during introduction of indwelling medical devices. Chemical, structural, technological and biological aspects of application of Tl(I) and Ag(I) cyanoximes-based coordination polymers are reviewed. Full article