Syntheses and Photochemically Induced Rearrangements of Tetrasilyl- and Trisilylgermyl Complexes of Iron:  (η⁵-C₅R₅)Fe(CO)₂(SiMe₂)₃EMe₂Ph (R = H, Me; E = Ge, Si)

Abstract

Oligosilyl and oligosilylgermyl complexes (η 5 -C 5 R 5 )Fe(CO) 2 (SiMe 2 ) 3 EMe 2 Ph (R ) H (1), Me (2); E ) Ge (a), Si (b)) have been synthesized, characterized, and photolyzed. All complexes isomerized cleanly to (η 5 -C 5 R 5 )Fe(CO) 2 E(SiMe 3 ) 2 (SiMe 2 Ph). Photolysis of a mixture of (η 5 -C 5 Me 5 )Fe(CO) 2 (SiMe 2 ) 3 GeMe 2 Ph (2a) and (η 5 -C 5 H 5 )Fe(CO) 2 (SiMe 2 ) 3 SiMe 3 (1b) proved that the rearrangements occur via an intramolecular mechanism. Irradiation of 1 and 2 in the presence of HMPA resulted in the formation of (η 5 -C 5 R 5 )Fe(CO)(dSiMe 2 ‚HMPA)(SiMe 2 -SiMe 2 EMe 2 Ph), indicating that silylene intermediates are key to the rearrangements. Attempts to use this new chemistry to perform the catalytic isomerization Me 3 GeSiMe 2 -SiMe 2 SiMe 2 H f (Me 3 Si) 3 GeH resulted in high yields of (Me 3 Si) 3 GeSiMe 2 H. This product indicates the ability of (Me 3 Si) 3 GeH to intercept the Fe-silylene intermediates.

Wagner–Meerwein-Type Rearrangements of Germapolysilanes - A Stable Ion Study

“…The product was crystallized by adding 2 mL of acetonitrile as a colorless, waxy solid (0.847 g, 80.6%). 1 H NMR (499.87 MHz, 305.0 K, CDCl 3 , δ ppm): 34 0.22 (s, 27H, (CH 3 ) 3 Si), 0.27 (d, 3 J H,H = 4.2 Hz, 6H, (CH 3 ) 2 Si), 4.12 (sept, 3 J H,H = 4.2 Hz, 1H, SiH). 13 C{ 1 H} NMR (125.71 MHz, 305.0 K, CDCl 3 , δ ppm): −1.4 ((CH 3 ) 2 Si), 3.1 ((CH 3 ) 3 Si).…”

“…29 Tris(trimethylsilyl)germyldimethylsilane (15). 34 Solutions of 2.99 mmol tris(trimethylsilyl)germylpotassium 28 in 30 mL of DME and of 0.6 mL (excess, 5.52 mmol) of chlorodimethylsilane in 30 mL of DME were cooled to 0 °C with an ice bath. The germylpotassium compound was slowly added to the chlorosilane solution during 1 h. The ice bath was allowed to warm to room temperature overnight.…”

Recent chemistry of the η5-cyclopentadienyl dicarbonyl iron anion

“…To understand more about the mechanistic aspects of photochemical-induced rearrangement of the tetrasilane complex, Fp(SiMe 2 ) 3 SiMe 3 , Sharma and Pannell prepared [137] the tetrasilane complex, Fp(SiMe 2 ) 3 SiMe 2 Ph (Scheme 79). Photolysis of the latter resulted in the rearranged product, FpSi(SiMe 3 ) 2 SiMe 2 Ph.…”

Synthesis and Characterization of m‐Terphenyl (1,3‐Diphenylbenzene) Compounds Containing Trifluoromethyl Groups

“…According to the data reported, another factor that cannot be neglected was the (E)/(Z) isomerization of the N¼N bond [21 -23]. Finally, the 29 Si{ 1 H}-NMR spectrum exhibited a singlet at À 6.0 ppm assigned to the Me 3 Si groups, i.e., in the chemical-shift range reported for similar compounds [24]. Additionally, in the IR spectrum, characteristic vibration bands for the N¼N and NÀN bonds were observed at 1429 and 1241 cm À1 , respectively [19 -21].…”