MOSSBAUER SPECTROSCOPY OF ORGANOMETALLIC COMPOUNDS - ALKYLTIN CYANIDES THIOCYANATES AND RELATED MOLECULES

Mössbauer, infrared, and nuclear magnetic resonance data are reported for a number of related alkyl-and aryltin thiocyanates and cyanides. From 119Sn isomer shift and quadrupole splitting data it is inferred that the R3SnCN and R3SnSCN compounds in the solid state adopt a trigonal-bipyramidal configuration involving a planar R3Sn moiety linked by bridging bidentate -CN- or -SCN-groups. The quadrupole splittings which are observed arise largely from the C3v symmetry around the metal atom and the difference in donor properties of the equatorial and axial ligands, rather than from pπ-pπ or pπ-dπ interactions. The Mössbauer and infrared data for the R2Sn(SCN)2 species are consistent with nearly octahedral symmetry around the metal atom in which the two R groups occupy trans coordination sites. Mössbauer data for frozen solutions of (C4H9)2Sn(SCN)2 in MHF (glassy matrix) and CH3CN (crystalline matrix) are interpreted in terms of an octahedral complex structure in which two solvent molecules occupy two of the six (equatorial) coordination sites. Nuclear magnetic resonance data for methyl- and ethyltin compounds can be correlated with 119Sn isomer shift data, an increase in the proton shift from TMS being reflected in an increase in the isomer shift, referred to SnO2. © 1969, American Chemical Society. All rights reserved.