Reactions of oligosilyl potassium compounds with Group 4 metallocene dichlorides

β-Amino- and Alkoxy-Substituted Disilanides

“…Both the fairly covalent interaction between Si and Zr as well as the steric demand of the Cp 2 Zr(Cl) unit caused an elongation of the central Si-Si distance of the Si(SiMe 3 ) 2 SiPh 2 NEt 2 moiety to 2.387(3) Å. The observed Si-Zr bond length of 2.863(2) Å is close to those found previously for Cp 2 Zr(Cl)Si(SiMe 3 ) 2 SiMe 2 Thex (2.853 Å) and Cp 2 Zr[Si(SiMe 3 ) 3 ] 2 (2.878 Å) [32]. However, compared to the structurally related complex Cp 2 Zr(Cl)Si(SiMe 3 ) 2 SiPh 2 F (d Si-Zr = 2.799(1)/2.803(1) Å) [19], the bond is significantly longer.…”

“…The 29 Si NMR resonances of the metallated silicon atoms of 3a and 3b were observed at −89.5 and −83.1 ppm, respectively. These values are close to those found for the structurally related compounds Cp 2 Zr(Cl)Si(SiMe 3 ) 3 (−89.5 ppm) and Cp 2 Hf(Cl)Si(SiMe 3 ) 3 (−79.7 ppm) [32]. The recently reported Cp 2 Zr(Cl)Si(SiMe 3 ) 2 SiPh 2 F exhibited a very similar value of −90.9 ppm [19].…”

“…Over the last years, we have prepared numerous oligosilanylated zirconocenes and hafnocenes, mostly by reaction of either potassium or magnesium oligosilanides with the respective group 4 metallocene dichlorides [31,32,33,34,35,36]. Reactions of 1b with zirconocene and hafnocene dichlorides proceeded analogously and provided access to complexes 3a and 3b (Scheme 2).…”

Group 4 Metal and Lanthanide Complexes in the Oxidation State +3 with Tris(trimethylsilyl)silyl Ligands

“…As expected, the values for Hf(III) are slightly longer but in essence the numbers are similar. For Cp 2 Hf{Si(SiMe 3 ) 3 } 2 the Cp centroid –Hf distance is 2.177 Å, 55 while for 3b this distance is elongated to 2.204/2.212 Å. We assume that the large Si–Hf–Si angle of 3b causes some population of antibonding Cp-Hf orbitals.…”

“…71 Chemicals were obtained from different suppliers and used without further purification. (18-crown-6)·K[Cp 2 TiCl 2 ] (M = Ti, Zr, Hf), 25 donor free tris(trimethylsilyl)silyl potassium ( 2a ), 30,40 tris(trimethylsilyl)germyl potassium ( 2b ), 72 1,4-dipotassium-tetramethyl-1,1,4,4-tetrakis(trimethylsilyl)tetrasilane·(18-crown-6) 2 ( 2c ), 73 Cp 2 Zr{Si(SiMe 3 ) 3 } 2 , 55 and Cp 3 Ce 74 were prepared following reported procedures. Elemental analysis was carried out using a Heraeus VARIO ELEMENTAR instrument.…”