Coordination Chemistry of Disilylated Stannylenes with Group 10 d¹⁰Transition Metals: Silastannene vs Stannylene Complexation

Abstract

The coordination behavior of disilylated stannylenes toward zerovalent group 10 transition metal complexes was studied. This was accomplished by reactions of PEt3 adducts of disilylated stannylenes with zerovalent group 10 transition metal complexes. The thus obtained products differed between the first row example nickel and its heavier congeners. While with nickel stannylene complex formation was observed, coordination of the stannylenes to palladium and platinum compounds led to unusual silastannene complexes of these metals. A computational model study indicated that in each case metal stannylene complexes were formed first and that the disilylstannylene/silastannene rearrangement occurs only after complexation to the group 10 metal. The isomerization is a two-step process with relatively small barriers, suggesting a thermodynamic control of product formation. In addition, the results of the computational investigation revealed a subtle balance of steric and electronic effects, which determines the relative stability of the metalastannylene complex relative to its silastannene isomer. In the case of cyclic disilylstannylenes, the Pd(0) and Pt(0) silastannene complexes are found to be more stable, while with acyclic disilylstannylenes the Ni(0) stannylene complex is formed preferentially.

Hydridoorganostannylene Coordination: Group 4 Metallocene Dichloride Reduction in Reaction with Organodihydridostannate Anions

“…For comparison, Ti−Sn complexes reported in literature exhibit longer interatomic distances: E 2.6940(9), F 2.7122(13), 2.7154(14), G 2.6867(16), 2.7254(17) Å (see Figure for molecular schemes). To the best of our knowledge, the observed Ti−Sn2 bond length is the shortest Ti−Sn bond characterized so far . Moreover, upon hydride abstraction the Ti‐Sn2‐C2 angle [167.4(1)°] exhibits a linearization of 23° in comparison to the bis(stannylene) complex 4 .…”

“…They observed the 1 H NMR signal at 19.4 ppm and the 119 Sn NMR signal at 786 ppm ( 1 J Sn−H 775 Hz) . Diorganostannylenes and disilylated stannylenes coordinated at metallocene fragments also exhibit signals at low field in the 119 Sn NMR (Figure : B 1677 ppm; E Ti 1635, Zr 1263, Hf 1080; F Hf 1785, Ti 2172 ppm) …”

Incorporating Methyl and Phenyl Substituted Stannylene Units into Oligosilanes. The Influence on Optical Absorption Properties

“…Structural parameters include Sn-Si bond distances of 2.6071(7) and 2.6099(8) Å and an Si–Sn–Si bond angle of 132.507(17)°. While a number of tin compounds with two attached tris(trimethylsilyl)silyl groups are known, most of the structurally characterized examples feature divalent tin, where the Sn–Si bonds are significantly elongated to values above 2.65 Å and the Si–Sn–Si bond angles are smaller than 115° [40,41,42,43]. Nevertheless dichlorostannane [(Me 3 Si) 3 Si] 2 SnCl 2 [37] was found to exhibit quite similar Si-Sn distances of 2.604(3) Å and the Si-Sn-Si angle of 142.5(1)° was even somewhat narrower than in 2 .…”

Anorganische Chemie 2013

“…Aus triethylphosphinstabilisierten, bis(silylierten) Stannylenen [R'Si(SiMe3)2]Sn·PMe3 entstehen als Folge einer 1,2‐Trimethylsilylgruppenmigration in der Koordinationssphäre der Übergangsmetalle die Palladium(0)‐ und Platin(0)komplexe der resultierenden Silastannene. Bei der Reaktion mit Ni(COD)2 wird die Silylgruppenwanderung unterdrückt, so dass ein Nickelstannylen isoliert wird 77…”