Phosphorous coordination of di- and tri-azaphospholes in platinum(0) complexes: X-ray molecular structure of tris(triphenylphosphine)-1,5-dimethyl-1,2,4,3-triazaphospholeplatinum(0) [Pt(PPh3)P=NN(Me)C(Me)=N]

Abstract

The azaphospholes P=NN(Me)C(Me)=N (L{N}) and P=C(H)C(Me)=NN(Me)(L{C}) have been used to synthesize the air-sensitive Pt}0{ complexes [Pt(PPh{3}){2}L{2}] and [Pt(PPhP{3}){3}L] (L = L{N}, L{C}), which are stable towards dissociation in solution at -40}o{C. One representative [Pt(PPh{3}){3}L{N}] (I) has been the subject of a single-crystal X-ray diffraction study. I is monoclinic, space group P2{1}/c, with a 15.680(5), b 13.679(6), c 27.82(2) @9, @b 113.86(4)}o{; Z = 4; R = 0.071 for 5492 observed reflections. The flat azaphosphole ligand is @s-P bonded to the metal centre (Pt-P 2.227(4) @9) which completes its pseudo-tetrahedral coordination sphere with the three PPh{3} groups (Pt-P{(}{a}{b}{)} 2.337 @9). }1{H and }3{}1{P NMR data for the new complexes are discussed.