[Ni₂O(l-Asp)(H₂O)₂]·4H₂O: A Homochiral 1D Helical Chain Hybrid Compound with Extended Ni−O−Ni Bonding

The hydrothermally synthesized 1D homochiral nickel aspartate oxide [Ni2O(l-Asp)(H2O)2]·4H2O is based on infinite helical chains of edge- and corner-sharing nickel octahedra. It represents the first example of a chiral one-dimensional compound with an extended helical TM−O−TM subnetwork synthesized as an optically pure product. Its structure was determined ab initio by real-space methods from laboratory powder diffraction data

[Ni₂O(l-Asp)(H₂O)₂]·4H₂O: A Homochiral 1D Helical Chain Hybrid Compound with Extended Ni−O−Ni Bonding

The hydrothermally synthesized 1D homochiral nickel aspartate oxide [Ni2O(l-Asp)(H2O)2]·4H2O is based on infinite helical chains of edge- and corner-sharing nickel octahedra. It represents the first example of a chiral one-dimensional compound with an extended helical TM−O−TM subnetwork synthesized as an optically pure product. Its structure was determined ab initio by real-space methods from laboratory powder diffraction data

[Ni₂O(l-Asp)(H₂O)₂]·4H₂O: A Homochiral 1D Helical Chain Hybrid Compound with Extended Ni−O−Ni Bonding

The hydrothermally synthesized 1D homochiral nickel aspartate oxide [Ni2O(l-Asp)(H2O)2]·4H2O is based on infinite helical chains of edge- and corner-sharing nickel octahedra. It represents the first example of a chiral one-dimensional compound with an extended helical TM−O−TM subnetwork synthesized as an optically pure product. Its structure was determined ab initio by real-space methods from laboratory powder diffraction data

A New Quasi-One-Dimensional Niobium Oxychloride Cluster Compound Cs₂Ti₄Nb₆Cl₁₈O₆: Structural Effects of Ligand Combination

The new niobium oxychloride cluster compound, Cs2Ti4Nb6Cl18O6, was obtained by solid-state synthesis techniques in the course of our systematic investigation of metal oxychloride systems aimed at the preparation of low-dimensional cluster compounds. Cs2Ti4Nb6Cl18O6 crystallizes in the trigonal system, with unit cell parameters a = 11.1903(7), c = 15.600(2) Å, space group P3̄1c, Z = 2. Its crystal structure was determined by single-crystal X-ray diffraction techniques. The full-matrix least-squares refinement against F2 converged to R1 = 0.048 (Fo > 4σ(Fo)), wR2 = 0.069 (all data). The structure is based on an octahedral cluster unit (Nb6C )C in which the six edge-bridging oxide ligands are arranged in two sets of three on opposite sides of the Nb6 octahedron. Ti3+ ions link the clusters through Oi and Cla ligands to form linear chains running along the c axis. The location of titanium ions correlates with the arrangement of oxide ligands around the Nb6 metal core. The chains interact with each other through additional Ti3+ and Cs+ ions. Interchain interactions are significantly weaker than intrachain interactions, resulting in a quasi-one-dimensional character of the overall structure

Preparation of Low-Dimensional Cluster Materials: Synthesis, Structure, and Properties of A₂Ti₂Nb₆Cl₁₄O₅ (A = K, Rb, Cs), a Series of One-Dimensional Titanium Niobium Oxychlorides

In the course of our systematic investigation of metal oxychloride systems aimed at the preparation of low-dimensional compounds, a new series of niobium oxychloride cluster compounds, A2Ti2Nb6Cl14O5 (A = K, Rb, Cs), was obtained from stoichiometric amounts of ACl (A = K, Rb, Cs), Ti, Nb2O5, NbCl5, and Nb, heated at 750 °C. The crystal structures of the series were determined by single-crystal X-ray diffraction techniques. The compounds crystallize in the monoclinic system, space group C2/c, with unit cell parameters a = 21.503(3) Å, b = 8.816(1) Å, c = 15.710(2) Å, β = 116.21(1)°, V = 2672.1(6) Å3, and Z = 4 for A = Rb. The full-matrix least-squares refinement against F 2 converged to R1 = 0.043 (Fo > 4σ(Fo)) and wR2 = 0.089 (all data for A = Rb). The crystal structure of A2Ti2Nb6Cl14O5 has one-dimensional character. It is based on chains formed by (Nb6   ) octahedral niobium clusters connected to each other through apical chloride ligands and titanium counterions. The chains are held together by alkali metal cations. Intracluster bond distances analysis indicates that the cluster has 14 valence electrons. Magnetic susceptibility study shows paramagnetic behavior with a magnetic moment of 2.17 μB per formula unit for two unpaired electrons contributed by two Ti3+

Preparation of Low-Dimensional Cluster Materials: Synthesis, Structure, and Properties of A₂Ti₂Nb₆Cl₁₄O₅ (A = K, Rb, Cs), a Series of One-Dimensional Titanium Niobium Oxychlorides

In the course of our systematic investigation of metal oxychloride systems aimed at the preparation of low-dimensional compounds, a new series of niobium oxychloride cluster compounds, A2Ti2Nb6Cl14O5 (A = K, Rb, Cs), was obtained from stoichiometric amounts of ACl (A = K, Rb, Cs), Ti, Nb2O5, NbCl5, and Nb, heated at 750 °C. The crystal structures of the series were determined by single-crystal X-ray diffraction techniques. The compounds crystallize in the monoclinic system, space group C2/c, with unit cell parameters a = 21.503(3) Å, b = 8.816(1) Å, c = 15.710(2) Å, β = 116.21(1)°, V = 2672.1(6) Å3, and Z = 4 for A = Rb. The full-matrix least-squares refinement against F 2 converged to R1 = 0.043 (Fo > 4σ(Fo)) and wR2 = 0.089 (all data for A = Rb). The crystal structure of A2Ti2Nb6Cl14O5 has one-dimensional character. It is based on chains formed by (Nb6   ) octahedral niobium clusters connected to each other through apical chloride ligands and titanium counterions. The chains are held together by alkali metal cations. Intracluster bond distances analysis indicates that the cluster has 14 valence electrons. Magnetic susceptibility study shows paramagnetic behavior with a magnetic moment of 2.17 μB per formula unit for two unpaired electrons contributed by two Ti3+

In(OH)BDC·0.75BDCH₂ (BDC = Benzenedicarboxylate), a Hybrid Inorganic−Organic Vernier Structure

The compound In(OH)BDC·0.75BDCH2 (BDC = benzenedicarboxylate), 1, has been synthesized and characterized by single-crystal X-ray diffraction. The structure comprises two distinct sublattices formed by a covalently linked In(OH)BDC lattice and ordered chains of hydrogen-bonded H2BDC molecules and can be described as a hybrid inorganic coordination polymer−organic vernier structure. Each InO6 octahedron of the octahedral chain has a length of 3.6 Å along the chain axis, whereas each H2BDC molecule has a length of 9.6 Å along the guest column axis. Therefore, a unit of eight InO6 octahedra of the octahedral chain is just in registry with three H2BDC molecules of the guest column giving a repeat unit of 28.76 Å along the channel axis direction

Influence of the Reaction Temperature and pH on the Coordination Modes of the 1,4-Benzenedicarboxylate (BDC) Ligand: A Case Study of the Ni^II(BDC)/2,2‘-Bipyridine System

Three new Ni(BDC)/2,2‘-bipy compounds, Ni2(BDC)(HBDC)2(2,2‘-bipy)2 (2), Ni3(BDC)3(2,2‘-bipy)2 (3), and Ni(BDC)(2,2-bipy)2·2H2O (5), in addition to the previously reported Ni(BDC)(2,2‘-bipy)·0.75H2BDC (1) and Ni(BDC)(2,2‘-bipy)(H2O) (4) [BDC = 1,4-benzenedicarboxylate; 2,2‘-bipy = 2,2‘-bipyridine], have been synthesized by hydrothermal reactions. A systematic investigation of the effect of the reaction temperature and pH resulted in a series of compounds with different compositions and dimensionality. The diverse product slate illustrates the marked sensitivity of the structural chemistry of polycarboxylate aromatic ligands to synthesis conditions. Compound 1, which has a channel structure containing guest H2BDC molecules, is formed at the lowest pH. The guest H2BDC molecules are connected by hydrogen bonds and form extended chains. At a slightly higher pH, a dimeric molecular compound 2 is formed with a lower number of protonated carboxylate groups per nickel atom and per BDC ligand. Reactions at higher temperature and the same pH lead to the transformation of 1 and 2 into the two-dimensional, layered trinuclear compound 3. As the pH is increased, a one-dimensional polymer 4 is formed with a water molecule coordinated to Ni2+. Bis-monodentate and bischelating BDC ligands alternate along the chain to give a crankshaft rather than a regular zigzag arrangement. A further increase of the pH leads to the one-dimensional chain compound 5, which has two chelating 2,2‘-bipy ligands. Crystal data:  2, triclinic, space group P1̄, a = 7.4896(9) Å, b = 9.912(1) Å, c = 13.508(2) Å, α = 86.390(2)°, β = 75.825(2)°, γ = 79.612(2)°, Z = 2; 3, orthorhombic, space group Pbca, a = 9.626(2) Å, b = 17.980(3) Å, c = 25.131(5) Å, Z = 4; 5, orthorhombic, space group Pbcn, a = 14.266(2) Å, b = 10.692(2) Å, c = 17.171(2) Å, Z = 8

Ti₂Nb₆O₁₂, a Novel Niobium Oxide Cluster Compound with “Chevrel Phase” Intercluster Connectivity Type

The niobium oxide cluster compound Ti2Nb6O12 was synthesized from NbO, NbO2, and TiO2 in the presence of NaF melt at 950 °C. It crystallizes in an original structure type based on octahedral cluster units (Nb6 ) . The clusters connect to each other through outer−inner linkages to form a three-dimensional framework containing cubeoctahedral cavities. The cluster connectivity pattern in Ti2Nb6O12 and intercluster metal−metal distances are similar to those found in the “Chevrel phases”. The Ti4+ ions have a distorted octahedral environment formed by the oxide ligands belonging to the clusters. Band structure calculations indicate that the lowest unoccupied band in Ti2Nb6O12 resembles the conduction band in the superconducting “Chevrel phases”

A Chain of Changes: Influence of Noncovalent Interactions on the One-Dimensional Structures of Nickel(II) Dicarboxylate Coordination Polymers with Chelating Aromatic Amine Ligands

Five one-dimensional coordination polymers, Ni(BDC)(1,10-phen) (1), Ni(BDC)(2,2‘-bipy)·0.75H2BDC (2), Ni(BDC)(1,10-phen)(H2O) (3), Ni(BDC)(1,10-phen)(H2O)·0.5H2BDC (4) and Ni(BDC)(2,2‘-bipy)(H2O) (5) [where BDC = 1,4-benzenedicarboxylate, 2,2-bipy = 2,2‘-bipyridine, and 1,10-phen = 1,10-phenanthroline] that have the same topology but markedly different geometry and packing of the chains have been synthesized by hydrothermal reactions. The results of variations of synthesis conditions and substitutions of 1,10-phenanthroline with 2,2‘-bipyridine indicate that incorporation of the coordinating water molecule, which affects the degree of bending of the chain, is primarily influenced by the amine ligand size, suggesting a substantial structural role of aromatic−aromatic interactions and amine ligand steric effects. The incorporation of the guest H2BDC molecules was found to be favored by lower pH conditions. Crystal data:  1, monoclinic, space group P21/n, a = 9.5589(6) Å, b = 12.6776(8) Å, c = 13.5121(9) Å, β = 95.437(1)°, Z = 4; 2, monoclinic, space group P21/c, a = 20.532(3) Å, b = 21.505(3) Å, c = 18.872(3) Å, β = 93.86(1)°, Z = 16; 3, triclinic, space group P1̄, a = 8.618(3) Å, b = 10.058(4) Å, c = 11.353(4) Å, α = 115.31(1)°, β = 92.33(1)°, γ = 94.03(1)°, Z = 2; 4, triclinic, space group P1̄, a = 9.7682(12) Å, b = 10.6490(13) Å, c = 11.2468(14) Å, α = 76.685(2)°, β = 65.309(2)°, γ = 85.612(2)°, Z = 2; 5, monoclinic, space group P21/c, a = 13.9683(9) Å, b = 17.4489(11) Å, c = 13.7737(9) Å, β = 99.12(1)°, Z = 8