TETRAALKYLAMMONIUM SALTS AS STEREOSPECIFIC ALKYLATING-AGENTS FOR HIGHLY NUCLEOPHILIC POLYPHOSPHIDE ZINTL ANIONS - PREPARATION OF [RP(7)W(CO)(3)](2-), [R(2)P(7)](-) AND R(2)R'P-7 COMPOUNDS FROM R(4)N(+) REAGENTS

[K(2,2,2-ctypt)](3) [P7W(CO)(3)] reacts with R(4)N(+) salts (R = Me, E t, n-Bu) in ethylenediamine (en) or dimethylformamide (DMF) solutions to give the [RP(7)W(CO)(3)](2-) ions (4) and R(3)N in high yields. Sim ilar reactions involving Me(n-C8H17N+ and (CH(2)Ph)Me(3)N(+) give the [MeP(7)W(CO)(3)](2-) and [(CH(2)Ph)P7W(CO)(3)](2-) ions, respectively. Reactions of [HP7W(CO)(3)](2-) with olefins did not affect insertions into the P-H bond to give compounds 4. These data indicate that the a lkylations proceed by way of nucleophilic attack at the alpha-carbon o f the tetraalkylammonium ions and not by a radical electron transfer p athway or a Hofmann elimination/olefin insertion pathway. Compounds 4 were characterized by H-1, C-13, and P-31 NMR and IR spectroscopic stu dies, microanalyses, and representative crystallographic studies. They possess C-1 symmetry in the solid state but display C-s symmetry in s olution due to an intramolecular wagging process. The P-31{H-1} NMR sp ectra for 4 reveal an AA'BB'MM'X spin system. Crystal data for [K(2,2, 2-crypt)](2)[EtP(7)W(CO)(3)]. en: triclinic, space group P ($) over ba r 1, a = 12.176(3) Angstrom, b = 15.106(2) Angstrom, c = 18.975(2) Ang strom, alpha = 93.509(10)degrees, beta = 98.833(13)degrees, gamma = 11 1.472(12)degrees, V = 3183.1(9) Angstrom(3), Z = 2; R(F) = 4.29% and R (w)(F-2) = 10.34%. The P-7(3-) ion reacts with excess R(4)N(+) (R = Me , Et, n-Bu) in en or DMF solutions to give symmetrical [R(2)P(7)](-) i ons (5) in quantitative yields. The reactions are stereospecific in th at only one of three possible isomers is formed in each case. Compound s 5 have been characterized by H-1, C-13 and P-31 and 2-D P-31-P-31 CO SY NMR spectroscopic studies. Compounds 5 react with alkyl halides, R' X where R'= CH(2)Ph, X = Cl; R' = Me, X = I; R' = n-Bu, X = Br to give mixtures of the symmetric and asymmetric isomers (similar to 1:10 rat ios) of R(2)R'P-7 compounds (6). The symmetric and asymmetric isomers are formed competitively from compounds 5 and do not interconvert in s olution. Spectroscopic studies on the formation of the (n-Bu)(3)P-7 co mpound (6e) show virtually quantitative ''one pot'' syntheses of compo unds 6 from the P-7(3-) parent ion but studies of the other members of compounds 6 were hampered by their low solubilities. Ah compounds 6 a re thermally unstable to some extent with the sterically hindered comp ounds being somewhat more robust than their less hindered analogs. The y have been characterized by P-31 NMR spectroscopy and FAB-MS (M + 1 m olecular ions).