254445-68-6Relevant academic research and scientific papers
N-substituted guanidinate anions as ancillary ligands in group 4 chemistry. Syntheses and characterization of M{RNC[N(SiMe3)2]NR}2Cl2, [M{CyNC[N(SiMe3)2]NCy}Cl3]- (M = Zr, Hf; R = iPr, Cy), and Zr{CyNC[N(SiMe3)2]NCy}(CH2Ph)3
Wood, Dayna,Yap, Glenn P.A.,Richeson, Darrin S.
, p. 5788 - 5794 (1999)
Addition of N(SiMe3)2 anion equivalents to carbodiimides, RN=C=NR (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 n 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.
