F-19, (31)P, H-1-NMR AND X-RAY CRYSTALLOGRAPHIC STUDIES OF 4-PYRAZOL-1-YL-2,3,5,6-TETRAFLUOROPHENYL)(N=1,2,3) PHOSPHINES

New phosphines 1-3 have been synthetized by reaction of pyrazolate ani on with tris(pentafluorophenyl)phosphine and characterized by H-1, P-3 1, and F-19 NMR studies. F-19 NMR spectral data contribute to the evid ence for a para-substitution of tetrafluorophenyl rings. The crystal s tructure of 4-pyrazol-1-yl-2,3,5,6-tetrafluorophenyl)phosphine 1 has b een determined, proving that the assignment based on spectroscopic dat a was correct: C27H9F12N6P, M(r) = 676.37, monoclinic, space group P2( 1)/c, a = 10.754(2) Angstrom, b = 10.316(2) Angstrom, c = 23.598(5) An gstrom, beta = 95.36(3)degrees, V = 2607(1), Angstrom(3), Z = 4, R(1) = 0.042, and wR(2) = 0.122.