WATER-SOLUBLE ELECTRON-DONATING PHOSPHINES - SULFONATION OF TRIS(OMEGA-PHENYLALKYL)PHOSPHINES

The series of phosphines P[(CH2)x(C6H5)]3, X = 1, 2,3, and 6, are sulfonated under relatively mild conditions to yield the corresponding sulfonated phosphines P[(CH2)x(C6H4-p-SO3Na)]3. Sulfonation occurs at both the para and ortho positions; the exclusively para-substituted products are isolated. The sulfonated phosphines are freely water soluble. Nickel carbonyl and palladium chloride derivatives of the phosphines are prepared, (PR3)Ni(CO)3 and (PR3)2Ni(CO)2 in THF/H2O solution and trans-(PR3)2PdCl2, under two-phase reaction conditions. Examination of the spectroscopically determined electronic and steric parameters shows that when x is large, the donor character of the water-soluble phosphines is virtually identical to that of the alkyl phosphine P(nBu)3.