Zirconocene dipicolinate and related dicarboxylate complexes: Coordination geometries and reactivities

Cytotoxic heteroleptic heptacoordinate salan zirconium(iv)-bis-chelates - synthesis, aqueous stability and X-ray structure analysis

Herein we report the synthesis and structural characterization of a series of novel Zr(iv)salan complexes. The initial metalation product [(L1)2Zr] is highly water sensitive while ligand exchanged [L1Zr(dipic)] hydrolyses slowly with a bis-hydroxo Zr(iv) species identified by MS as an intermediate. [L1Zr(dipic)] is cytotoxic in the range of cisplatin against two human carcinoma cell lines.

Organometallic Fluorides of Zirconium and Hafnium in the Synthesis of Carboxylate Complexes: Molecular Structures of [{(eta(5)-C(5)Me(5))ZrF(OCOCF(3))(2)}(2)] and [(eta(5)-C(5)Me(5))(2)Zr(OCOCF(3))(2)]

The reaction of [(eta(5)-C(5)Me(5))ZrF(3)] and [(eta(5)-C(5)Me(5))HfF(3)] with Me(3)SiOCOCF(3) yields the dinuclear complexes [{(eta(5)-C(5)Me(5))ZrF(OCOCF(3))(2)}(2)] (1) and [{(eta(5)-C(5)Me(5))HfF(OCOCF(3))(2)}(2)] (2), regardless of the molar ratio employed. [(eta(5)-C(5)Me(5))(2)ZrF(2)] reacts with 1 and 2 equiv of Me(3)SiOCOCF(3) to form the mononuclear compounds [(eta(5)-C(5)Me(5))(2)Zr(OCOCF(3))(2)] (3) and [(eta(5)-C(5)Me(5))(2)ZrF(OCOCF(3))] (4), respectively. The molecular structures of 1 and 3 have been determined by single-crystal X-ray analysis: 1, triclinic, P&onemacr;, a = 9.508(3) Å, b = 11.002(4) Å, c = 17.528(3) Å, alpha = 78.55(4), beta = 76.80(2), gamma = 87.51(2) degrees, V = 1750(1) Å(3), Z = 2, R = 0.0378; 3, monoclinic, C2/c, a = 18.553(4) Å, b = 9.110(2) Å, c = 16.323(3) Å, beta = 114.88(3) degrees, V = 2503(1) Å(3), Z = 4, R = 0.0457. Compound 1 shows bridging bidentate and chelating carboxylate ligands as well as bridging fluorine atoms. The zirconium atoms are seven coordinated and have an 18-electron configuration. X-ray studies of 3 reveal two structural components where the carboxylate ligands coordinate in a monodentate (major component) and a chelating manner (minor component).