SPECTRA-STRUCTURE CORRELATIONS IN 2,2'-BIPYRIDINE MERCURY(II) SACCHARINATE - COMPARISON WITH MERCURY(II) SACCHARINATE AND CHLOROMERCURY(II)SACCHARINATE

The infrared spectrum of 1:1 complex of mercury(II) saccharinate with 2,2'-bipyridine, [Hg(C7H4N)3S)2(C10H8N2)), was studied in the CO and S O2 stretching regions. The appearance of the spectrum in the region of the carbonyl stretching modes was correlated with the number of non-e quivalent CO groups in the structure. The spectral and structural char acteristics of the CO groups in the title compound were compared with the corresponding ones in the mercury(II) saccharinate and chloromercu ry(II) saccharinate. It was found that the frequency of the CO stretch ings in the spectrum of Hg(bpy)(sac)2 is significantly lower (1630 and 1615 cm-1) than the frequency of the corresponding modes in the spect ra of covalently bonded mercury(II) saccharinate (1705 and 1680 cm-1) and chloromercury saccharinate (1694 cm-1). An attempt was also made t o assign the bands which are mainly due to the symmetric and the antis ymmetric SO2 stretching vibrations.