Synthesis and Reactivity of Silicon Transition Metal Complexes, 34. Pentachlordisilanyl‐ und Disilanyl‐Komplexe von Molybdän und Wolfram: Darstellung, Struktur und spektroskopische Charakterisierung

Abstract

Reaction of the lithium metallates Li[M(PMe3)(CO)2C5R5] are reconverted into 3a-d in the presence of tetrachlorome-[M = Mo, W; R = H (la, b), Me (lc, d)] with Si2C16 (2) leads thane. Extensive spectroscopic investigations (NMR, Raman, to the formation of the pentachloro(metal1o)disilanes and IR spectroscopy) were performed to establish the transi-C5R5(OC)2(Me3P)M-SiC12-SiC13 (3a-d), which are transfor-tion-metal effect especially with respect to the H5Si, ligand. med into the metallo disilanes C5R5(0C)2(Me3P)M-SiH2-The molecular structure of C5Me5(0C)2(Me3P)W-SiClz-SiH3 (4a-d) on treatment with LiA1H4. The disilanes 4a-d SIC4 (3d) was determined by single-crystal X-ray diffraction.

Iron and Ruthenium Fragment Substituted Disilanes C5R5(OC)2M–Si2X5 (R = H, Me; M = Fe, Ru; × = Cl, H): Synthesis, Structural and Raman Spectroscopic Characterisation, DFT Calculation

“…attached to the silicon atoms this species represent a shortlived intermediate which is confirmed only by IR matrix In accordance with former experiments [6] a suspension of studies [4] or by the isolated photolysis product Cp(OC) 2-the sodium metalates 1a؊d in cyclohexane is combined FeϪSiR 3 .…”

“…[6] These ligands offer the possibility to study the influence of the transition metal fragment on the exchange reactivities of the silicon atoms in α-or β-position as well as on the stability of the MϪSiϪSi bonding arrange- [ ] Materials,Vol. 3,(Eds.…”

“…[5] [6] Therefore, we have undertaken efforts to establish efficient routes for the synthesis of metallo-pentachloro-and -pentahydridodisilanes. [6] These ligands offer the possibility to study the influence of the transition metal fragment on the exchange reactivities of the silicon atoms in α-or β-position as well as on the stability of the MϪSiϪSi bonding arrange- [ ] Materials,Vol.…”

“…The DFT calculations Si1ϪSi2 distance of 2.333(9) Å (2a), 2.335(11) Å (3b) is close to that of known disilanes (e. g. Me 6 Si 2 : 2.340 Å [22] ) show that this vibration is indeed a pure SiSi stretching, and no other internal coordinates are involved. So, we can conclude that changes in the electronic density of the metal atom have no influence on this bond.…”

“…2.298(9) Å (3b) lies within the range of known iron silicon tadienyl unit found for 2a, 3b is typical for pseudo-tetrahedral halfsandwich iron complexes of the type C 5 R 5 (OC) 2-FeϪSi 2 X 5 (X ϭ H, Cl, alkyl); [21h] at the metal centre more crowded complexes like the pseudo tetragonal monopyramidal tungsten compoundC 5 Me 5 (OC) 2 (Me 3 P)WϪSiCl 2 Ϫ SiCl 3 prefer the trans arrangement. [6] Distorsion with respect to the ideal conformation of about 20°(3b)/ 8°(2a) for all the substituents at Si1 deduced from the dehedral angles Cp(Z)ϪFe1ϪSi1ϪSi2 (82.6°)/(68.2°), Cp(Z)ϪFe1Ϫ Si1ϪH11 (41.7°)/ Cp(Z)ϪFe1ϪSi1ϪCl1 (51.7°) and Cp(Z)ϪFe1ϪSi1ϪH12 (159.3°)/ Cp(Z)ϪFe1ϪSi1ϪCl2 (6.2°) indicates the higher sterical demand of the SiX 3 group compared to the hydrogen or chlorine atoms.…”