METALLO-METHANES AND METALLO-METALLANES .19. VIBRATIONAL AND MULTINUCLEAR NMR-SPECTRA OF ANIONIC MERCURIOMETHANES [CH4-N(HGX)N]N-

Vibrational spectra of solid sodium sulfitomercuriomethanates Nan[CH4-n(HgSO3)n]·nH2O (2 ≤ and ≤ 4) exhibit high frequencies of the valence vibrations νas(SO3) > νs(SO3) (average 1057 cm-1) with big differences νas - νs (mean 104 cm-1), and ν(HgS) vibrations in the 200 to 230 cm-1 range, thus indicating S-coordinated sulfite ligands. Force field calculations for the ion [C(HgSO3)4]4- yield high force constants K(S-O) = 605 N/m, K(Hg-S) = 258 N/m, and even K(C-Hg) = 181 N/m.- For thiosulfatomercuriomethanates [CH4-n(HgS2O3]n- (1 ≤ n ≤ 4) in aqueous solutions Raman spectra suggest S-coordination with high νas(SO3) and νs(SO3) (average 1130 cm-1), and low ν(S-S) (∼420 cm-1) frequencies, and strong ν(Hg-S) bands (∼250 cm-1). From 1H, 13C and 199Hg NMR data is concluded that the CHg bond strengths in the series decrease on a lower level than in other mercuriomethanes.- On the whole, the electronic properties of the peripheral ligands X in the mercuriomethanes CH4-n(HgX)n seem to be more important for the CHg bond strengths than the total charge. © 1990.