Synthesis and structure of mono- and binuclear copper(II) complexes with polyfunctional nitroxide 4-(1'carboxy-2'-oxopropylidene)-2,2,5,5-tetramethyl-3-imidazolidine-1-oxyl, [Cu(LH)(2)(H2O)(2)] and [Cu(2)L(2)(H2O)(5)]. Catepillar-like reaction

Cu-II reacted with the polyfunctional nitroxide 4-(1'-carboxy-2'-oxopropylidene)-2,2,5,5-tetramethyl-3-imidazolidine-1-oxyl (H(2)L; Cu/H(2)L = 1:2) to yield Cu(LH)(2)(H2O)(2), which was characterized by strong fixation of water molecules exclusively by hydrogen bonds. In the interaction of Cu(LH)(2)(H2O) with an additional amount of Cu-II (Cu/H(2)L = 1:1), the ligands moved towards each other in parallel directions to form the binuclear compound Cu(2)L(2)(H2O). This process is very unusual in coordination chemistry. Copyright (C) 1997 Elsevier Science Ltd.