Wasserlösliche Phosphane V. Komplexe amphiphiler tertiärer alkylphosphane mit Ammoniumgruppierungen in den seitenketten

Abstract

Monocationic amphiphilic tertiary phosphines [RMe 2N-(CH 2) n-PR ′ 2] + X − ( 1–3) obtained by P-alkylation of the corresponding primary phosphines (R′  H) form stable tungstencarbonyl-, Rh(I)-olefin- and square planar Pd(II)-complexes ( 4–8a). Stepwise protonation of [Me 2N-(CH 2) 2] 3P ( 9) by Ph 3P · HBr or aqueous HCl affords tricationic tertiary phosphine ligands, e.g. {[HMe 2N-(CH 2) 2] 3P} 3+ 3X − ( 13, 13b) and the phosphonium salt {[HME 2N-(CH 2) 2] 3P-H} 4+ 4Cl − ( 13a). The pK a-values 9.67, 8.86, 7.92 and 1.9 have been obtained by titration of 13a with NaOH in aqueous solution. Highly charged Pd(II)-complexes ( 16a, 16b) with extreme water solubilities were obtained from 13 and PdBr 2 or by N-protonation of cis-PdCl 2(9) 2 with HCI. The crystal structures of 13 · 0.5H 2O and { trans-{[HMe 2N-(CH 2) 2] 3P}) 2PdCl 2} 6+ 6Cl −· 2MeOH ( 16b) (space group C2/c) have been determined. While the P( … N) 3 skeleton of the trication in 13 is almost flat, it is folded back on coordination to palladium(II) in 16b.