Applications of119mSn Mössbauer Spectroscopy to the Study of Organotin Compounds

Tin(IV) Compounds with 2-C6F4PPh2 Substituents and Their Reactivity toward Palladium(0): Formation of Tin–Palladium Complexes via Oxidative Addition

“…Further analysis of the NLMOs reveals that compounds 5 , 6 , and 8 are best described as having predominantly covalent Sn III –Pd I bonds (X-type stannyl ligand), with the palladium contribution to the bond being only slightly greater; i.e., the ratio of contributions of Sn and Pd atoms to the electronic population of the bond orbital (tin/palladium) ranges between 0.7 and 0.8 (Table ). Complex 7 , which also has the smallest value of the 119 Sn Mössbauer isomer shift [and is in the expected range for formal tin­(IV) compounds] exhibits pronounced Sn IV ←Pd 0 characteristics of the metal–metal bonding situation (Z-type tin ligand; Chart ) because the Pd atom is the formal electron pair (LP) donor (tin/palladium ratio of 0.25). The energy associated with the donor–acceptor interaction of a palladium-located LP (76% palladium and 19% tin contribution to this LP) into an empty orbital at tin amounts to 42.0 kcal·mol –1 , and further donation into the three σ*­(Sn–C) orbitals contributes another 25.5 kcal·mol –1 .…”

Bis(di-tert-butylindenyl)tetrelocenes

“…Therefore, we assume that signal B can be assigned to SnO 2 , or, respectively, organotin oxygen derivates resulting from hydrolysis and/or oxidation of 2b . 19–21 Signal C shows an isomer shift of δ = 2.80(1) mm s −1 and a quadrupole splitting of Δ E Q = 2.03(3) mm s −1 which is comparable to the Mössbauer spectroscopic data of Sn(OH) 2 ( δ = 2.83(6) mm s −1 ; Δ E Q = 2.20(6) mm s −1 or other organotin hydroxide byproducts, 20–22 which may also result from hydrolysis of 2b . All observed line widths are in the usual range for 119 Sn Mössbauer spectroscopic investigations.…”

Bonding and Metal-Atom Dynamics in Two Unique Sn(I)−Sn(III) Complexes

“…As the extensive compilations of Zuckerman et al have shown, major contribution to the QS of the a site arises from the lone pair of electrons in the proximity of the Sn(II) atom. The QS of the b site is surprisingly small in terms of known tri-organo ligand structures, but there is little in the literature here to serve as a guide to compounds in which such a fragment is ligated to a Sn(II) atom.…”