Structures of NN′-ethylenebis(monothioacetylacetoneiminato)nitrosylcobalt and NN′-ethylenebis(2-hydroxyacetophenoneiminato)nitrosylcobalt

Abstract

The cobalt atoms in both [Co(NO)(sacacen)] and [Co(NO)(7-Mesalen)] {sacacenH₂ isNN′-ethylenebis(monothioacetylacetoneimine) and 7-MesalenH₂ isNN′-ethylenebis(2-hydroxyacetophenoneimine)} are 5-coordinate, with a tetragonal-pyramidal arrangement of donor atoms. The cobalt atom in [Co(NO)(sacacen)] lies just above the plane defined by the SNNS donor atoms of the quadridentate ligand, and the nitrosyl group occupies the apical position. A similar geometry is defined by the ONNO donor atoms and the NO group in [Co(NO)(7-Mesalen)]. The Co-N-O angles are strongly bent, as predicted from¹⁵N-nmr studies (127.2(6)°[Co(NO)(sacacen)] and 127.4(3)°[Co(NO)(7-Mesalen)]). Both nitrosyls crystallize in the monoclinic system. For [Co(NO)(sacacen)],a=8.501,b=12.673,c=13.866 Å,β=95.00°,Z=4 and space groupP2₁/c. The structure was determined by the heavy-atom method, usingMo Kα diffractometer data, and refined by full matrix least squares toR=0.062 for 2920 observed reflections. For [Co(NO)(7-Mesalen)],a=9.461,b=13.053,c=13.456,β=99.32°,Z=4 and space groupP2₁/c. The structure was determined as above toR=0.040 for 2461 observed reflections.