2004年8月
Synthesis, magnetic properties and MCD spectra of a four coordinate copper(II) complex with two chelated phenolate-substituted imino nitroxides
INORGANICA CHIMICA ACTA
- ,
- ,
- ,
- ,
- ,
- ,
- ,
- 巻
- 357
- 号
- 11
- 開始ページ
- 3125
- 終了ページ
- 3133
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1016/j.ica.2004.03.017
- 出版者・発行元
- ELSEVIER SCIENCE SA
A reaction of Cu(II) nitrate and 4,4,5,5-tetramethyl-2-(2-hydroxophenyl)imidazolin-1-oxyl (IM2PhOH) with potassium methoxide in methanol gave a homoleptic bis(imino nitroxide) complex of [Cu(IM2PhO)(2)] (1). The single-crystal X-ray analysis of 1 showed that the imino nitroxide anion, IM2PhO(-), chelated to a Cu-II ion via an imino-N and a phenoxide-O atoms to form a six-membered chelate ring. The coordination geometry around the Cu(II) ion was a distorted square-planar polygon; the dihedral angle between the two coordination planes, each of which was defined by Cu and two ligating atoms of IM2PhO(-), was 40.81degrees. The temperature dependences of the magnetic susceptibility and the EPR spectra of 1 indicate that the magnetic interaction between Cu(II) and the imino nitroxide is ferromagnetic, while there is a moderate antiferromagnetic interaction between two coordinated imino nitroxides. A balance between these opposite interactions attains the lowest molecular doublet spin-state in 1. The variable temperature magnetic circular dichroism (MCD) spectrum of the complex 1 also showed two negative components with a large C term, which may be due to the charge-transfer (CT) transition originated from the d orbital to the SOMO pi* orbital in the spin-coupled IM2PhO(-) radicals; resulting in the largely split doublet excited states with the spin singlet and triplet d(8) configurations. (C) 2004 Elsevier B.V. All rights reserved.
- リンク情報
- ID情報
-
- DOI : 10.1016/j.ica.2004.03.017
- ISSN : 0020-1693
- Web of Science ID : WOS:000223311700001