New silylated iminophosphorano(amino)phosphines Me(3)SiN=PPh(2)N(R)PPh(2) (R = Et, (n)Pr, (n)Bu). Crystal and molecular structure of trimethylsilyliminophosphorano(propylamino)diphenylphosphine Me(3)SiN=PPh(2)N((n)Pr)PPh(2). Further oxidative derivatization with S, Se, and azides, titanium(IV) transmetalation of the imine, and syntheses of rhodium(I), palladium(II), and platinum(II) complexes of these iminophosphorano(amino)phosphines.

Abstract

Bis(phosphino)amines Ph(2)PN(R)PPh(2) (R = Et, (n)Pr, (n)Bu) react with stoichiometric amounts of trimethylsilyl azide to give the trimethylsilyliminophosphorano(amino)phosphines Me(3)SiN=PPh(2)N(R)PPh(2) (1, R = Et; 2, R = (n)Pr; 3, R = (n)Bu) as crystalline compounds. The structure of 2 has been determined by single-crystal X-ray analysis. (Crystal data for 2: monoclinic, P2(1)/c, a = 10.235(1) A, b = 16.802(2) A, c = 17.075(2) A, beta = 101.05(1) degrees, V = 2882.9(5) A(3), Z = 4.) The structure of 2, which is the first example of an iminophosphoranophosphine with the P(III)-N-P(V)=N skeleton, was solved by direct methods and refined to R = 0.044. Compound 2 readily reacts with elemental sulfur, selenium, or phosphoryl azide to give fully oxidized phosphinimines Ph(2)P(E)N((n)()Pr)Ph(2)P=NSiMe(3) (4, E = S; 5, E = Se; 6, E = NP(O)(OPh)(2)). Compounds 4-6 are very sensitive to moisture and readily undergo desilylation to give the parent phosphinimines Ph(2)P(E)N((n)()Pr)Ph(2)P=NH, which can be isolated as moderately stable crystalline solids. The phosphiniminophosphine 2 and the oxidized phosphinimines (4 and 5) react with CpTiCl(3) to give new nitrogen-bound Ti(IV) derivatives Ph(2)P(E)N((n)Pr)Ph(2)P=NTi(Cp)Cl(2) (10, E = lone pair; 11, E = S; 12, E = Se). Compounds 1-3 readily react with rhodium(I), palladium(II), and platinum(II) complexes to give five-membered metallacycles via phosphorus(III) and imine nitrogen coordination.