Ligandenaustauschreaktionen an Kupfer(II)‐Komplexen mit Harnstoffliganden: Synthesen, Strukturen, EPR‐Spektroskopie

Abstract

AbstractThe synthesis of copper(II) and nickel(II) complexes of N,N‐diethyl‐N'‐benzoylurea HL1, N,N‐diethyl‐N'‐(2, 6‐difluorbenzoyl)urea HL2, N,N‐diethyl‐N'‐benzoylthiourea HL3, N,N‐diethyl‐N'‐(3, 4, 5‐trimethoxybenzoyl)thiourea HL4 and N,N‐diethyl‐N'‐benzimidoylthiourea H2L5 and the crystal structures of HL2, [Cu(L2)2] and [Ni(HL5)2] are reported. All CuII complexes were investigated by EPR spectroscopy in liquid and frozen solutions. The CuII complex [Cu(HL5)2] was additionally studied as diamagnetically diluted powder system [Ni(HL5)2] / [Cu(HL5)2] (99:1). The calculation of electron spin‐density distribution in the first coordination sphere of [Cu(HL5)2] is represented, based on well‐resolved 63, 65Cu and 14N hyperfine structure (hfs) couplings. Ligand exchange reactions of CuII complexes of urea type ligands HL1–4 and H2L5 were studied by means of EPR spectroscopy in liquid solutions. Statistical and quantitative runs were derived from concentration‐dependent hfs line intensities.