Synthesis and structure of E-2-(2,4,6-tri-tert-butylphenylphosphinyl)-2-[N-(tert-butyldimethylsilyl)-N-(p-chrolophenyl)]amino-1-(2,4,6-tri-tert-butyl-phenyl)phosphacthylene

The title compound E-2-(2, 4, 6-tri-tert-butylphenylphosphinyl)-2-[N-( tert -butyldimethysilyl)-N-( p-chrolophenyl)] amino-1-(2, 4, 6-tri-tert-butylphe nyl)phosphacthylene(C49H78NClP2Si, M-r=806.65) was synthesized and characte rized by X-ray diffraction analysis. The crystal is monoclinic, space group P 2(1) / n with a=10.319(3), b=23.309(5), c=21.41(1) Angstrom, beta=99.64( 5)degrees, V=5078(3) Angstrom (3), Z =4, D-c=1.05g/cm(3), F(000)=1760, mu=1 .92cm(-1). Due to the steric hindrance from substituents around phosphaethy lene, the P=C bond length is significantly longer than those observed in it s analogues. The values of the three bond angles involved in the sp(2)-hybr idized carbon atom (C(1)) of the phosphaethyrene are 133.4, 115.1 and 111.4 degrees respectively, deviating significantly from the ideal value of 120 degrees. In addition, although 5 sp(2)- hybridized atoms (C(2), P(1), C(1), N and C(44)) are sequentially bonded in this molecule, no interaction is o bserved among the remaining pz orbits of these atoms on the string.