Synthesis of Dihalogenobis(2-pyridinethiolato)tin(IV) by the Oxidative Addition of Bisulfide to Tin(II) Halides—Consideration on the Coordination Structure

The reaction of di-2-pyridyl disulfide with tin(II) halides was found to give dihalogenobis(2-pyridinethiolato)-tin(IV). The oxidative addition reaction was successfully extended to the preparation of other dihalogenodi-thiolatotin(IV) complexes. Dichlorobis(2-pyridinethiolato)tin(IV) was also prepared by the reaction of 2(1H)-pyridinethione with tin(IV) chloride and proposed to be a monomeric, octahedral complex with a four-membered (Sn, S, C, and N) chelate ring from its molecular weight and IR spectral data. Dichlorobis(2-quinolinethiolato)tin(IV) could be isolated similarly as a stable complex. However, attempts to isolate the dichlorodithiolatotin(IV) in which an intramolecular chelation seems hardly possible were unsuccessful. The great stability of bis(2-pyridinethiolato)- and bis(2-quinolinethiolato)-dihalogenotin(IV) could be ascribed to the intramolecular four-membered chelate ring formation for the six-coordination of tin atom.