title: Synthesis and Mössbauer spectroscopy of formal tin(II) dichloride and dihydride species supported by Lewis acids and bases.
abstract: (119)Sn Mössbauer spectroscopy was performed on a series of formal Sn(II) dichloride and dihydride adducts bound by either carbon- or phosphorus-based electron pair donors. Upon binding electron-withdrawing metal pentacarbonyl units to the tin centers in LB·SnCl2·M(CO)5 (LB = Lewis base; M = Cr or W), a significant decrease in isomer shift (IS) was noted relative to the unbound Sn(II) complexes, LB·SnCl2, consistent with removal of nonbonding s-electron density from tin upon forming Sn-M linkages (M = Cr and W). Interestingly, when the nature of the Lewis base in the series LB·SnCl2·W(CO)5 was altered, very little change in the IS values was noted, implying that the LB-Sn bonds were constructed with tin-based orbitals of large p-character (as supported by prior theoretical studies). In addition, variable temperature Mössbauer measurements were used to determine the mean displacement of the tin atoms in the solid state, a parameter that can be correlated with the degree of covalent bonding involving tin in these species.
authors.affiliation: Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr., Edmonton, Alberta, Canada T6G 2G2.
authors.forename: S M Ibrahim
authors.initials: SM
authors.lastname: Al-Rafia
authors.forename: Olena
authors.initials: O
authors.lastname: Shynkaruk
authors.forename: Sean M
authors.initials: SM
authors.lastname: McDonald
authors.forename: Sean K
authors.initials: SK
authors.lastname: Liew
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ferguson
authors.forename: Robert
authors.initials: R
authors.lastname: McDonald
authors.forename: Rolfe H
authors.initials: RH
authors.lastname: Herber
authors.forename: Eric
authors.initials: E
authors.lastname: Rivard