Volatile intracomplex compounds with a spin-labeled enaminoketone containing an isopropyl group

Abstract

1. Volatile intracomplexes ML2 [M=Co(II), Ni(II), Cu(II), Zn(II), Pd(II)] with the novel paramagnetic ligand 4-(3-methyl-2-oxobutylidene)2,2,5,5-tetramethylimidazolidine-1-oxyl have been obtained. 2. In the solid phase and in solution, CoL2, CuL2 and ZnL2 have the tetrahedral structure at the MN2O2 center while PdL2 has the square structure. In the solid phase, the chelate NiL2 has the square structure, while in solution the NiN2O2 center has tetrahedral symmetry. On undergoing the square → tetrahedral transition, the low-spin d8 configuration is converted into the high-spin state.