Thiosemicarbazide complexes of mercury (II) halides

Abstract

CHUSG CHIEH, LAURA P. C. LEE, and CECILEA CHIU. Can. J. Cheni. 56,2526Cheni. 56, (1978. Dibromobis(thiosen~icarbazide)mercury(TI) HgBr,(tsc),, is isostructural with dichlorobis-(thioseniicarbazide)mercury(II). The crystal is orthorhornbic with n = 8.825(9), h = 8.587(1 I), In both HgCI,(tsc), and HgBr,(tsc),, the configuration of the coordinated thioseniicarbazide (tsc) is the same as that of the free molecule. The ir and Raman (R) spectra for the complexes and tsc in the region 300-1600 cm-' are T-ery similar. The strong band at 800 (807 R) em-' in the tsc due to v(C-S) is shifted to 773 (796 R), 777 (796 R), and 660 (680 R) cm-' for HgC12-(tsc),, HgBr,(tsc),, and HgCl,(tsc) correspondingly. A strong band at 368 (R) em-' present uniquely for HgCl,(tsc) can be assigned to v(Hg-K). The halides in HgX,(tsc), are bonded to one mercury(I1) ion and weakly bridged to a neighboring molecule with Hg ... CI = 3.250 (3) fi and Hg ... Br = 3.436(4) A. As a result, two Raman bands due to Hg-X are expected. For HgCl,(tsc),, the two Rarnan bands occur at 236 and 166 cm-', whereas for HgBr,(tsc),, one was observed at 190 em-' but the other was masked by lattice modes. In HgCl,(tsc), the two Hg-CI bonds are different and bands at 220 and 190 cm-' are assigned to v(Hg--CI),.CHUKG CHIEH, LAURA P. C. LEE et CECILIA CHIU. Can. J. Chem. 56,2526Chem. 56, (1978. [Traduit par le journal Le dibromobis (thiosernicarbazide)n~erc~~re(II), H g B~~( t s c )~, est isostructural avec la dichlorobis(thiose~nicarbazide)mercure(II). Le cristal est orthorhomhique avec