Abstract
The synthesis, characterization, and reactivity of several group 4 metal complexes featuring a central anionic pyrrole moiety connected via CH(2) linkers to two phosphine donors is described. Treatment of [P(NH)P-iPr] with [MCl(4)(THF)(2)] (M = Zr, Hf) in the presence of base yields the dimeric complexes [M(PNP(iPr))(μ-Cl)(Cl)(2)](2) featuring two bridging chloride ligands. These complexes react with sodium cyclopentadienyl and SiMe(3)I to give the mononuclear complexes [M(PNP(iPr))(η(5)-Cp)(Cl)(2)] and [M(PNP(iPr))(I)(3)], respectively. The latter react with MeMgBr to form the trialkyl complexes [M(PNP(iPr))(Me)(3)]. Upon treatment of [Ti(NMe(2))(4)] with [P(NH)P-iPr] a complex with the general formula [Ti(PNP(iPr))(NMe(2))(3)] is obtained. DFT calculations revealed that the most stable species is [Ti(κ(1)N- PNP(iPr))(NMe(2))(3)] featuring a κ(1)N-bound PNP ligand. When [P(NH)P-iPr] is reacted with [Ti(NMe(2))(4)] in CH(2)Cl(2) complex [Ti(PNP(iPr))(Cl)(2)(NMe(2))] is formed. Treatment of a solution of [P(NH)P-iPr] and [Zr(NMe(2))(4)] with SiMe(3)Br affords the anionic seven-coordinate tetrabromo complex [Zr(PNP(iPr))(Br)(4)][H(2)NMe(2)]. The corresponding hafnium complex [Hf(PNP(iPr))(Br)(4)][H(2)NEt(2)] is obtained in similar fashion by utilizing [Hf(NEt(2))(4)] as metal precursor. All complexes are characterized by means of NMR spectroscopy. Representative complexes were also characterized by X-ray crystallography. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00706-024-03171-x.