Crystal structure of a three-dimensional neodymium(III) coordination polymer, [Nd2(H2O)6(glutarato)(SO4)2] n

A three-dimensional coordination polymer, poly[hexaaqua(μ4-glutarato)bis(μ3-sulfato)dineodymium(III)], [Nd2(H2O)6(glutarato)(SO4)2] n (glutarato2– = C5H6O4 2–), 1, consisting of cationic {Nd2(H2O)6(SO4)2} n 2n+ layers linked by bridging glutarate ligands, was synthesized by the microwave-heating technique within few minutes. The crystal structure of 1 consists of two crystallographically independent TPRS-{NdIIIO9} (TPRS is tricapped trigonal–prismatic geometry) units that form an edge-sharing dinuclear cluster interconnected to neighbouring dimers by the μ3-SO4 2– anions, yielding a cationic two-dimensional {Nd2(H2O)6(SO4)2} n 2n+ sheet. Adjacent cationic layers are then linked via the μ4-glutarato2– ligands into a three-dimensional coordination network. Strong O—H...O hydrogen bonds are the predominant interaction in the crystal structure.

Copper(II) Carboxylates with 2,3,4-Trimethoxybenzoate and 2,4,6-Trimethoxybenzoate: Dinuclear Cu(II) Cluster and µ-Aqua-Bridged Cu(II) Chain Molecule

Copper(II) complexes with 2,3,4-trimethoxybenzoic acid (H234-tmbz) and 2,4,6-trimethoxybenzoic acid (H246-tmbz), [Cu2(234-tmbz)4(H2O)2] (6) and [Cu(246-tmbz)2(µ-H2O)2(H2O)2]n (7), were synthesized and characterized by elemental analysis, infrared and UV-vis spectra and temperature dependence of magnetic susceptibilities (1.9–300 K). The X-ray crystal structures revealed that the former 6 is a dinuclear cluster having syn-syn-bridged Cu2(µ-234-tmbz)4 core with Cu···Cu separation of 2.6009(7) Å, while the latter 7 is a µ-aqua-bridged chain molecule consisting of Cu(246-tmb)2(µ-H2O)2(H2O)2 units with Cu···Cu separation of 4.1420(5) Å. Temperature dependence of magnetic susceptibilities showed that an antiferromagnetic interaction with 2J = −272 cm−1 for 6 and a weak antiferromagnetic interaction with J = −0.21 cm−1 for 7, between the two copper(II) ions. The adsorption isotherm of 6 showed Types I behavior having a 125.4 m2g−1 of specific surface area.

Structure of tetrakis(μ-decanoato-κ2 O:O′)bis[(4-methylpyridine-κN)copper(II)], a dimeric copper(II) complex

The 4-methylpyridine (4-Mepy) based dimeric copper(II) carboxylate complex [Cu2(C10H19O2)4(C6H7N)2] or [Cu2(μ-O2CC9H19)4(4-Mepy)2] crystallizes with triclinic (P\overline{1}) symmetry. The two CuII ions exhibit a distorted square-pyramidal environment and are connected into a centrosymmetric paddle-wheel dinuclear cluster [Cu...Cu = 2.6472 (8) Å] via four bridging carboxylate ligands arranged in the syn–syn coordination mode. The apical positions around the paddle-wheel copper centers are occupied by the N atoms of the 4-methylpyridine ligands. The structure exhibits disorder of the terminal alkyl carbon atoms in the decanoate chains.

The first coordination compound of deprotonated 2-bromonicotinic acid: crystal structure of a dinuclear paddle-wheel copper(II) complex

A copper(II) dimer with the deprotonated anion of 2-bromonicotinic acid (2-BrnicH), namely, tetrakis(μ-2-bromonicotinato-κ2 O:O′)bis[aquacopper(II)](Cu—Cu), [Cu2(H2O)2(C6H3BrNO2)4] or [Cu2(H2O)2(2-Brnic)4], (1), was prepared by the reaction of copper(II) chloride dihydrate and 2-bromonicotinic acid in water. The copper(II) ion in 1 has a distorted square-pyramidal coordination environment, achieved by four carboxylate O atoms in the basal plane and the water molecule in the apical position. The pair of symmetry-related copper(II) ions are connected into a centrosymmetric paddle-wheel dinuclear cluster [Cu...Cu = 2.6470 (11) Å] via four O,O′-bridging 2-bromonicotinate ligands in the syn-syn coordination mode. In the extended structure of 1, the cluster molecules are assembled into an infinite two-dimensional hydrogen-bonded network lying parallel to the (001) plane via strong O—H...O and O—H...N hydrogen bonds, leading to the formation of various hydrogen-bond ring motifs: dimeric R 2 2(8) and R 2 2(16) loops and a tetrameric R 4 4(16) loop. The Hirshfeld surface analysis was also performed in order to better illustrate the nature and abundance of the intermolecular contacts in the structure of 1.

Structural characterization of HypX responsible for CO biosynthesis in the maturation of NiFe-hydrogenase

Several accessory proteins are required for the assembly of the metal centers in hydrogenases. In NiFe-hydrogenases, CO and CN− are coordinated to the Fe in the NiFe dinuclear cluster of the active center. Though these diatomic ligands are biosynthesized enzymatically, detail mechanisms of their biosynthesis remain unclear. Here, we report the structural characterization of HypX responsible for CO biosynthesis to assemble the active site of NiFe hydrogenase. CoA is constitutionally bound in HypX. Structural characterization of HypX suggests that the formyl-group transfer will take place from N10-formyl-THF to CoA to form formyl-CoA in the N-terminal domain of HypX, followed by decarbonylation of formyl-CoA to produce CO in the C-terminal domain though the direct experimental results are not available yet. The conformation of CoA accommodated in the continuous cavity connecting the N- and C-terminal domains will interconvert between the extended and the folded conformations for HypX catalysis.

Assembly of various degrees of interpenetration of Co-MOFs based on mononuclear or dinuclear cluster units: magnetic properties and gas adsorption

Mononuclear or dinuclear Co cluster units are interconnected by mixed ligands, resulting in interesting structural diversity and various degrees of interpenetration.

Highly luminescent lanthanide CPs based on dinuclear cluster: crystal structure and sensitive Trp sensor

A lanthanide coordination polymer is explored as Trp sensor. The possible sensing mechanism is the combination between Trp and Tb3+, which improves the antenna effect.