N-(2,6-Dimethylphenyl)diphenylphosphinamine chalcogenides (S, Se) and a zirconium complex possessing phosphanylamide in the coordination sphere

Abstract

We report the syntheses of N-(2,6-dimethylphenyl)-P,P-diphenylphosphinothioic amide Ph₂P(S)NH-(2,6-Me₂C₆H₃)] (2) and N-(2,6-dimethylphenyl)-P,P-diphenylphosphinoselenoic amide Ph₂P(Se)NH-(2,6-Me₂C₆H₃)] (3) by the reaction of N-(2,6-dimethylphenyl)-P,P-diphenylphosphinamine [Ph₂PNH-(2,6-Me₂C₆H₃)] (1) with elemental sulphur and selenium respectively. When the phosphinamine compound 1 was treated with n-BuLi and subsequently with zirconocenedichloride in an equimolar ratio, the corresponding zirconium complex [{η⁵-Cp₂ZrCl(η²-N(2,6-Me₂C₆H₃)PPh₂}] (5) was obtained in good yield. The solid state structures of all the compounds were established by single crystal X-ray diffraction analysis. In zirconium complex 5, a highly strained three membered metallacycle was observed. In addition, the solid state structure of [Ph₂P(O)NH(2,6-Me₂C₆H₃)] (4) was also determined. In the solid state structure, compound 4 shows extensive intermolecular hydrogen bonding through oxygen atoms, whereas a lesser extent of intermolecular hydrogen bonding was noted in compound 2, due to the presence of the less electronegative sulphur atom.