Copper(II) complexes bearing cyclobutanecarboxylate and pyridine ligands: a new series of dinuclear paddle-wheel complexes

Abstract

Four members of a new series of paddle-wheel copper(II) complexes bearing cyclobutanecarboxylate as bridging ligand with pyridine derived ligands in axial positions are reported. They have been characterised by FTIR-ATR, UV-Vis spectroscopy, mass spectrometry, and single crystal X-ray diffraction. The synthesis is straight-forward by combining the carboxylic acid, copper(II) acetate, and a slight excess of a pyridine ligand. The molecular structures of three complexes reveal a coordination mode expected for such type of dinuclear copper(II) carboxylates.

Synthesis, crystal structures and DFT studies of Co(ii) and Zn(ii) coordination polymers of terephthalate and 4,4′-trimethylenedipyridyl ligands for removal of dibenzothiophene from a model fuel oil

“…40 Characteristic bands for ν asymmetric (COO − ) and ν symmetric (COO − ) stretches observed at 1580 cm −1 and 1370 cm −1 , respectively, in the spectrum of 2 give an insight into the bridging binding mode of tpa carboxyl to Zn( ii ). 41 Other bands such as the azomethine stretches [ ν (CN)], ν (C–H) and ν (CC) were also observed in both spectra at typical wavenumbers as reported in the literature. 40…”

“…The average bond distance between Co( ii ) and the tmdp nitrogens is 2.168 Å while the distance between Co( ii ) and the chlorides is 2.451 Å, both typical of theoretical Co( ii )–N and Co( ii )–Cl bond distances. 40,41,43 The coordination geometry around cobalt is an almost perfect octahedral geometry with the N–Co–Cl bond angles in the range 88.59–91.67°, averaging 90.00°, while the N–Co–N bond angles are in the range 88.29–92.11°, averaging 90.01°. The dihedral angles between the Co–N equatorial planes and the coordinated tmdp pyridine rings are 50.20(17) and 50.4(2)°.…”

“…If the Zn1–O12 bond is considered coordinating, then one tpa is bonded to the Zn in a bridging mode of 122.03° with Zn–O; bond distances of 1.994 and 2.556 Å while the other tpa is bonded to the opposite end via a deprotonated hydroxy oxygen with a Zn–O bond distance of 1.967 Å. 41 A geometry index ( τ 5 = −0.01667 α + 0.01667 β , where α and β are the two highest valence angles and β > α ) with a value of 0.78 was observed, the coordination center is considered a slightly distorted trigonal bipyramidal. 47 The structure has an infinite 2-dimensional zig-zag polymeric structure with a sql topology (Fig.…”

Synthesis and Characterization of a New Cu(II) Paddle-Wheel-like Complex with 4-Vinylbenzoate as an Inorganic Node for Metal–Organic Framework Material Design

“…In particular, Cu-MOFs are used for the adsorption of carbon dioxide, methane, and nitrogen [ 14 ]. Copper is an appropriate metal for the generation of paddle-wheel-like structures [ 15 , 16 , 17 ], which can be applied to biochemical processes, such as gas separation, adsorption, and catalysis [ 15 ]. Recently, we reported on the copper complex [Cuphen(vba) 2 H 2 O] (vba: 4-vinylbenzoic acid; phen: phenanthroline), from which a corresponding metal-imprinted polymer (MIP), [Cuphen(vba) 2 H 2 O- co -EGDMA] n (EGDMA: ethylene glycol dimethacrylate), was successfully obtained and used as an adsorbent for heavy metals [ 18 ].…”