Ti-Sn, Zr-Sn, and Hf-Sn heterodimetallic complexes: Stabilizing unsupported group 4-group 14 metal-metal bonds

Reaction of the tripodal amido complexes [MeSi{SiMe2N(4-CH3C6H4)}(3)ZrCl] a nd [MeSi-{SiMe2N(4-CH3C6H4)}(3)HfCl] with LiSnPh3 in toluene yielded the Zr -Sn and Hf-Sn complexes [MeSi{SiMe2N(4-CH3C6H4)}(3)ZrSnPh3] (1) and [MeSi{S iMe2N(4-CH3C6H4)}(3)-HfSnPh3] (2), while attempts to synthesize the corresp onding Ti-Sn complex resulted in the oxidative coupling of the stannate to give Ph3Sn-SnPh3 and unidentified titanium species. More stable group 4-gro up 14 complexes were obtained by reaction of the triamido stannate complex [MeSi{SiMe2N(4-CH3C6H4)}(3)SnLi(OEt2)] With the metallocene dichlorides [Cp 2MCl2] of all three titanium group metals, giving [MeSi{SiMe2N(4-CH3C6H4)}( 3)SnM(eta (5)-C5H5)(2)(Cl)] (M = Ti, 3; Zr, 4; Hf, 5). X-ray diffraction st udies of 4 and 5 established Zr-Sn and Hf-Sn bond lengths of 3.02313(17) an d 2.9956(3) Angstrom, respectively.