MOBILITY STUDIES ON SOL-GEL PROCESSED ETHER-PHOSPHINES AND THEIR RUTHENIUM(II) COMPLEXES WITH DIFFERENT SPACER LENGTHS - A SOLID-STATE NMR-STUDY

The monomeric ether-phosphine ligands (MeO)(3)Si(CH2)(x)(Ph)PCH(2)CH(2 )OMe {x = number of methylene groups; x = 3 [1a(T-0)], 6 [1b(T-0)], 8 [1c(T-0)]} and their P-coordinated trimethoxysilyl-(T)-functionalized ruthenium complexes cis-Cl(H)Ru(CO)(P similar to O)(3) [2a(T-0)(3)], [ 2b(T-0)(3)], and [2C(T-0)(3)] were sol-gel processed with fixed amount s of Si(OEt)(4) (Q(0)), MeSi(OMe)(3) (T-0), and Me(2)Si(OEt)(2) (D-0) to give the polysiloxane-bound ether-phosphine ligands [1(a,b,c) (T-n) (Q(k),T-m,D-i)(y)] and the ruthenium complexes [2(a,b,c) (T-n)(3)(Q(k) ,T-m,D-i)(y)] [P similar to O: eta(1)-P-coordinated ether-phosphine li gand; y = number of co-condensed Q, T, or D type; Q = Q type silicon a tom (four oxygen neighbors), T = T type silicon atom (three oxygen nei ghbors), D = D type silicon atom (two oxygen neighbors); i, k, n, m = number of Si-O-Si bonds; i = 0-2; n, m = 0-3; k = 0-4]. Solid-state Si -29 NMR spectroscopy has been used to show that the matrixes containin g ligands or complexes have comparable structures, independently from the employed spacer (n-propyl, n-hexyl, or n-octyl). Detailed P-31 NMR relaxation time studies (T-1P, T-PH, T-1 rho H), 2D WISE NMR spectros copy, and the line widths of the P-31 CP/MAS NMR spectra have been app lied for dynamic investigations. The noncomplexed ether-phosphine liga nds are highly mobile and their flexibility is enhanced by longer spac ers for all types of matrixes. The mobility of the ligands is also dep endent upon the employed co-condensate. Functionalized F-T/Q copolymer s are less flexible than F-T/T or even F-T/D copolymers [F = -(CH2)(x) P(Ph)CH(2)CH(2)OMe]. The P-coordination of the ether-phosphines in the complexes led to an additional cross-linking in the matrixes. Thereby the ligands become more rigid due to strong phosphorus-ruthenium bond s. The differences of the mobilities of the different polymer-bound co mplexes are smaller compared to the noncomplexed ligands.