Metal Azidonitrosyl Complexes: Synthesis and Characterization of Some Novel Mononuclear and Binuclear Chromium(I) Azidonitrosyl Derivatives from Chromate(VI) Involving Heterocyclic Nitrogen Donors

摘要

Novel mixed-ligand azidonitrosyl complexes of chromium(I), found by the interaction of pentaazidonitrosylchromate(I) anion, [Cr(NO)(N_3)_5]~(3-) (obtained by interaction of K_2CrO_4, NaN_3, KOH and NH_2OH.HCl), with some heterocyclic bases, viz., 2-hydroxymethylpyridine (2-HMP), methyl nicotinate (MNIC), 2-(2'-aminoethyl)pyridine (2-AEP), 2-picoline (2-PIC), 3-picoline (3-PIC) and 4-picoline (4-PIC) in aqueous acetic acid, aerobic media are described~ The resulting mixed-ligand complexes, which have been characterized by analytical data, molar conductances, magnetic measurements, thermogravimetric analyses, electron spin resonance, infrared and electronic spectral studies, have the compositions, [Cr(NO)(N_3)_2(L)_2], where L = 2-HMP (1), 2-PIC (2), 3-PIC (3) or 4-PIC (4), [Cr(NO)(N_3)_2(2-AEP)] (5), [{Cr(NO)(N_3)_2}_2(MNIC)_2] (6). Suitable mononuclear and binuclear, cis-square based pyramidal structures have been proposed for these complexes. Chromium(I) has a low-spin {CrNO}~5 electron configuration in these paramagnetic complexes, which behave as non-electrolytes.