N-Substituted Guanidinate Anions as Ancillary Ligands in Group 4 Chemistry. Syntheses and Characterization of M{RNC[N(SiMe<sub>3</sub>)<sub>2</sub>]NR}<sub>2</sub>Cl<sub>2</sub>, [M{CyNC[N(SiMe<sub>3</sub>)<sub>2</sub>]NCy}Cl<sub>3</sub>]<sup>-</sup> (M = Zr, Hf; R = <sup>i</sup>Pr, Cy), and Zr{CyNC[N(SiMe<sub>3</sub>)<sub>2</sub>]NCy}(CH<sub>2</sub>Ph)<sub>3</sub>
收藏资源简介：
Addition of N(SiMe3)2 anion equivalents to carbodiimides, RNCNR (R = cyclohexyl, isopropyl), generated tetrasubstituted guanidinates which provided entry to a series of bis- and mono(guanidinate) complexes of Zr and Hf exhibiting the general formulas {RNC[N(SiMe3)2]NR}2MCl2 (R = isopropyl, M = Zr (1), Hf (2); R = cyclohexyl, M = Zr (3), Hf (4) and {CyNC[N(SiMe3)2]NCy}MCl4]- (M = Zr (5), Hf (6)) depending on the metal:ligand ratio used in the reaction. In addition to spectroscopic characterization, definitive evidence for the molecular structures of these products is provided through single-crystal X-ray analyses for 1, 3, 4, 5, and 6, which are presented. These results further define the ligand-bonding parameters and provide clear evidence that the planar N(SiMe3)2 functional groups and the MNCN planes have a nearly perpendicular orientation and therefore do not experience significant π overlap. Complex 5 provides an access to the organometallic derivative {CyNC[N(SiMe3)2]NCy}Zr(CH2Ph)3 (7) by reaction with 3 equiv of PhCH2MgCl. Single-crystal X-ray analysis confirmed the connectivity of this species and indicated an η2-benzyl group. These results provide the first reported example of an organozirconium complex supported by a guanidinate ligand.
