SB-121 MOSSBAUER-SPECTRA OF ORGANOANTIMONY DERIVATIVES CONTAINING SB-SB BONDS

121-Sb Mossbauer data are reported for a number of organoantimony ring s and catena-stibanes. These compounds are representative of RSb(Sb)(2 ) and R(2)SbSb type of coordination, and spectral parameters are compa red and discussed in relation to RSbCl(2) and R(2)SbCl systems. Althou gh the trend in isomer shift is similar, the present compounds show sl ightly less negative isomer shift values together with a remarkable re duction of the quadrupolar coupling constant. A rationalization of the quadrupolar interaction in the above series of compounds appears feas ible by using point charge model calculations whose results, in terms of bonding, indicate a large contribution of p-electron density along Sb-Sb bonds.