Tris- und tetrakis(trimethylsilyl)cyclopentadien

A Homologous Series of Base‐Free Organo(alkaline‐earth) Metallocenes: Synthesis and Molecular Structures of [1,2,4‐(SiMe3)3C5H2]2(Ca, Sr, Ba)

“…We have been examining the properties of 1,2,4-tris(trimethylsilyl)cyclopentadiene (HCp 3Si ) [12,13] as a sterically bulky ligand in s-block metal chemistry. [14,15] In conjunction with the previously reported structure of the substituted magnesocene [1,2,4- [16] a homologous series of unsolvated Group-2 metallocenes from Mg to Ba has now been synthesized and crystallographically authenticated.…”

Carbosilane dendrimers containing peripheral cyclopentadienyl niobium- and tantalum-imido complexes

“…Unless otherwise stated, reagents were obtained from commercial sources and used as received. LiCp 0 (Cp 0 = g 5 -C 5 H 4 SiMe 3 ) [22], [TaCl 4 Cp * ] (Cp * = g 5 -C 5 Me 5 ) [23], silylated anilines Gn-{(C 6 H 4 )N(SiMe 3 ) 2 } m , and niobium derivatives Gn-{(C 6 H 4 )NNbCl 2 Cp 0 } m (n = 0,1,2; m = 1, 4, 8, respectively) [6b] were prepared according to the literature procedures. (1)ANb (1)ACp (1) 104.87 Nb(1)AC(Cp (1)) b 2.491 (7) Cl (1)ANb (1)ACp (2) 105.98 Nb(1)AC(Cp(2)) b 2.491 (7) Cl (1)ANb (1)AO (1) 94.71 (18) a Cp (1) and Cp(2) denote the cyclopentadienyl-centroid of C1AC5 and C6AC10 rings, respectively.…”

Synthesis and reactivity of new mono- and dinuclear niobium and tantalum imido complexes: X-ray crystal structure of [Ta(η5-C5H4SiMe3)Cl2{NC6Me4-4-(N(SiMe3)2)}]

“…2.415(7) Ta(1)-C (4) 2.504(6) Ta(1)-C (5) 2.472(1) N(1)-C (11) 1.396(6) N(2)-C (8) 1.452(6) N(2)-Si (2) 1.743(5) N(2)-Si (3) 1.741 (5) Bond angles (°) N(1)-Ta(1)-Cl(1) 102.9(1) N(1)-Ta(1)-Cl (2) 101.9(1) Cl(1)-Ta(1)-Cl (2) 103.16(7) Ct(1)-Ta(1)-Cl (1) 113.5 Ct(1)-Ta(1)-Cl (2) 112.0 (3) 125.9 (3) Ct (1) is the centroid of C(1)-C(5). (4), with thermal ellipsoids at 30% probability.…”

“…Solvents were distilled from appropriate drying agents and degassed before use. Li{PhC(NSiMe 3 ) 2 } [10], Li(C 5 H 4 SiMe 3 ) [11], [Ta(g 5 -C 5 H 4 SiMe 3 )Cl 4 ] [12] and [Nb(g 5 -C 5 H 4 SiMe 3 )Cl 4 ] [13] were prepared as described earlier. LiNMe 2 and 2,3,5,6-tetramethyl-1,4-phenylenediamine were purchased from Aldrich and used without further purification.…”