Dinuclear zinc(II) complex of a new acyclic phenol-based dinucleating ligand with four methoxyethyl chelating arms: first dizinc model with aminopeptidase function
Polar crystals were formed using a chiral dinuclear nickel(II) complex [Ni,(bomp)(R/S-OCOCH(CH3)Ph)(2)]BPh4 as a building unit. [H(bomp): 2,6-bis[bis(2-methoxyethyl)aminomethyl]-4-methylphenol; H(R/S-OCOCH(CH3)Ph): R/S-2-phenylpropionic acid]. Single-crystal X-ray analysis revealed that the symmetry of the crystal was C, and the complex cations were orientated along the polar axis. The crystals showed pyroelectric and second-order electro-optic effects, which are characteristic of polar materials. (c) 2005 Elsevier B.V. All rights reserved.
Synthesis, structure, and magnetic properties of dinuclear nickel(II) complexes with a phenol-based dinucleating ligand with four methoxyethyl chelating arms
Dinuclear nickel(II) complexes [Ni-2(bomp)(MeCO2)(2)]BPh4 (1) and [Ni-2(bomp)(PhCO2)(2)]BPh4 (2) were synthesized with the dinucleating ligand 2,6-bis[bis(2-methoxyethyl)aminomethyl]-4-methylphenoI [H(bomp)]. X-Ray analysis revealed that the complex 1 center dot 0.5CHCl(3) contains two nickel(II) ions bridged by phenolic oxygen and two acetate groups, forming a mu-phenoxo-bis(mu-acetato)dinickel(II) core. Electronic spectra were investigated for I and 2 in the range of 400-1800 nm, and the data were typical for the octahedral high-spin nickel(II) complexes. Obtained spectral components were well simulated based on the angular overlap model assuming the trigonally distorted octahedral geometry. Magnetic susceptibility was measured for 1 and 2 over a temperature range of 4.5-300 K. The optimized magnetic data were J = 1.75 cm(-1) zJ' = -0.234 cm(-1) g = 2.21, D = 15.1 cm(-1) and TIP = 370 x 10(-6) cm(-1) for complex 1 and J = 3.55 cm(-1), zJ'= -0.238 cm(-1), g = 2.23, D = 21.8 cm(-1), and TIP = 470 x 10(-6) cm(-1) for complex 2. The data revealed ferromagnetic interactions between the two nickel(II) ions. (c) 2004 Elsevier B.V. All rights reserved.