Band assignments in the i.r. spectrum of cis,cis-bis(glycinato)cis-bis(imidazole)nickel(II) by multiple isotopic labelling

Abstract

Abstract The i.r. spectra of cis -[Ni(gly) 2 (Him) 2 ] (gly = glycinate ion, Him = imidazole) and its isotopically-labelled analogues have been determined over the range 4000-150 cm −1 . 18 O -, 15 N -, 1- 13 C -, 2- 13 C -, and 2,2- d 2 -labelling of the coordinated glycinate yields assignments for the internal glycinate modes and the nickel—oxygen and nickel—nitrogen stretching and bending vibrations while deuteration of imidazole (Him- d 3 ) provides assignments for the internal modes of the coordinated imidazole rings and for the nickel—imidazole vibrations. The results, combined with those of previous multiple isotopic labelling studies on glycinate complexes, enable some general conclusions to be reached on the i.r. spectra of these compounds.