Article ID Journal Published Year Pages File Type
1334648 Polyhedron 2013 13 Pages PDF
Abstract

The work in this paper presents syntheses, characterization, crystal structures, catecholase activity, electrospray ionization mass spectroscopy (ESI-MS positive), and magnetic properties of seven triple bridged μ-phenoxo-bis(μ-carboxylate) dicopper(II) complexes [CuII2L(μ-HCOO)2](ClO4)·CH3OH (1), [CuII2L(μ-CH3COO)2](ClO4) (2), [CuII2L(μ-CCl3COO)2(H2O)](ClO4) (3), [CuII2L(μ-CH3CH2COO)2](ClO4) (4), [CuII2L(μ-CH3CH2CH2COO)2](ClO4) (5), [CuII2L(μ-PhCOO)2](ClO4)·CH3CN (6) and [CuII2L(μ-o-ClPhCOO)2](ClO4) (7), one double bridged μ-phenoxo-μ1,1-azide system [CuII2L(μ1,1-N3)(N3)2] (8) and one double bridged μ-phenoxo-μ-methoxide system [CuII2L(μ-OCH3)(NCO)2] (9), derived from a new dinucleating ligand HL, which is the 1:2 condensation product of 2,6-diformyl-4-ethylphenol and 3-dimethylaminopropylamine. The variable-temperature (300–2 K) magnetic studies reveal moderate or strong antiferromagnetic interaction in 1–9 with J values of −81.5, −64.8, −136.5, −66.9, −61.4, −49.1, −61.5, −186.3 and >−350 cm−1 for 1–9, respectively. The seven μ-phenoxo-bis(μ-carboxylate) dicopper(II) complexes 1–7 show catecholase activity with turnover (Kcat) numbers lying in the range 18.8–89.1 h−1. The positive ions observed in the ESI-MS spectra of 1–8 are heterobridged dinuclear species having oxidized CuIICuII or reduced CuICuI or mixed-valence CuIICuI metal centers having double/triple bridging moieties. A complex-substrate aggregate [CuII2L(μ-3,5-DTBC2−)]+ has been identified in the ESI-MS positive spectrum of the mixture of complex 4 and 3,5-DTBCH2.

Graphical abstractThe work in this paper presents syntheses, characterization, crystal structures, magnetic properties, catecholase activity, and electrospray ionization mass spectral (positive) studies of seven μ-phenoxo-bis(μ-carboxylate), one μ-phenoxo-μ1,1-azide, and one μ-phenoxo μ-methoxide dicopper(II) complexes derived from a new dinucleating ligand (carboxylate = formate, acetate, trichloroacetate, propionate, butyrate, benzoate, and o-chlorobenzoate).Figure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemistry Inorganic Chemistry
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