Molybdenum and tungsten Cp* complexes that contain 2,2′-diamidodiphenylamido or 2-amido-2′-oxydiphenylamido ligands

Cp*MCl4 compounds (M = Mo or W) react with 2-amino-2'-hydroxydiphenylamine ([H2NNHOH]) to yield complexes of the type Cp*M[HNNO]Cl. An X-ray study of the one electron reduction product, {Na(C2H5)(2)O}{Cp*Mo[HNNO]Cl}, showed it to contain square pyramidal {Cp*Mo[HNNO]Cl) ions weakly connected by bridging Na(ether) units. Cp* W[HNNO]Cl could be oxidized readily by AgOTf in acetonitrile to produce {Cp*W[HNNO]Cl) +OTf-. Both Cp*M[HNNO]Cl compounds are reduced by hydrazine to give the diamagnetic compound, Cp*M[HNNO](NH3). An X-ray structure of Cp*Mo[HNNO](NH3) showed that the almost planar [HNNO](3-) ligand and the ammonia ligand occupy the four basal positions in an approximately square pyramidal "piano stool" complex. Red crystalline Cp*W[HNNNH]Cl ([HNNNH](3-) = [(2-NHC6H4)(2)N](3-)) could be prepared from Cp*WCl4 and 2,2'-diaminodiphenylamine. It can be oxidized with AEOTf or NOPF6 to yield {Cp*W[HNNNH]Cl}X (X = OTf or PF6). {Cp*W[HNNNH]Cl)PF6 reacts with three equivalents of NH2NMe2 to afford Cp*W[HNNNH](NNMe2), with four equivalents of isopropylamine to produce Cp*W[HNNNH](N-i-Pr), and with water in the presence of K2CO3 to yield Cp*W[HNNNH](O). Cp*W[(HNNNH]Cl reacts with dimethyl zinc at 80 degrees to give Cp*W[HNNNH]Me, which can be subsequently oxidized by silver triflate to give {Cp*W[HNNNH]Me}OTf. Deprotonation of {Cp*W[HNNNH]Me}OTf with DBU yielded an imido complex, Cp*W[(2-N-C6H4)(2'-NH-C6H4)N]Me via loss of one of the two ligand NH protons. (C) 1998 Elsevier Science Ltd. All rights reserved.