Synthesis of Tungsten Carbonyl and Nitrosyl Complexes of Monodentate and Chelating Aryl-N-sulfonylphosphoramides, the First Members of a New Class of Electron-Withdrawing Phosphine Ligands. Comparative IR and (13)C and (31)P NMR Study of Related Phosphorus Complexes.
Reaction of N,N'-bis(tolylsulfonyl)-1,2-diaminoethane with PhPCl(2) gives in 62% yield the phosphonous diamide 2-phenyl-1,3-bis(p-tolylsulfonyl)-1,3,2-diazaphospholidine (4, "TosL") and with Ph(2)PCl in 43% yield the diphosphinous amide N,N'-bis(diphenylphosphino)-N,N'-bis(p-tolylsulfonyl)-1,2-ethanediamine (5, "diTosL"). Reaction of 4 with (THF)W(CO)(5) gives (TosL)W(CO)(5) (6) in 77% yield, and reaction of 5 with trans-BrW(CO)(4)NO gives cis, cis, trans-(diTosL)W(CO)(2)(NO)Br (8) in 86% yield. The IR, (13)C NMR, and (31)P NMR spectra of 4, 5, 6, and 8 are compared to those of a variety of compounds including LW(CO)(5) (L = PMe(3), PPh(3), PPh(NEt(2))(2), P(OMe)(3), P(CF(3))(3)), L(2)W(CO)(2)(NO)Br (L(2) = Ar(2)PCH(2)CH(2)PAr(2) (Ar = Ph (diphos), C(6)F(5) (diphos-F(20))), (CH(3)CN)(2)), and the free ligands as appropriate. The IR data are interpreted to suggest a relative ordering of ligand acceptor ability of P(CF(3))(3) > 4 approximately P(OMe)(3) > PPh(3) approximately PPh(NEt(2))(2) and a relative ordering of ligand donor ability of PPh(NEt(2))(2) >/= P(OMe)(3) > PPh(3) > 4 > P(CF(3))(3). The chelating ligand diTosL is about as electron-withdrawing as diphos-F(20), on the basis of the IR data. The (31)P NMR data qualitatively support the conclusion that TosL and diTosL are highly electron-withdrawing ligands, on the basis of (1)J(PW). The (13)C data do not permit any such generalizations, although the spectra of the diphosphine ligands and adducts are of interest due to the observation of "virtual coupling" that surprisingly can be simulated only as ABX rather than AA'X spin-systems.
Hersh
William H.
WH
Department of Chemistry and Biochemistry, Queens College of the City University of New York, Flushing, New York 11367-1597.
Xu
Ping
P
Wang
Bing
B
Yom
Jong Won
JW
Simpson
Cheslan K.
CK