Sol-gel processed phosphine ligands with two T- or D-silyl functionalilties and their (eta(5)-C5Me5)Ru(II) complexes

A new class of hemilabile D- and T-functionalized ether phosphine ligands o f the type MeOCH2CH2P[(CH2)(z)SiMem(OMe)(3-m)](2) [3a,b,d,e(T-0) (m = 0: z = 3 (a), 6 (b), 8 (d), 14 (e)), and 3c(D-0) (m = 1; z = 6 (c))] was obtaine d by treatment of 2-methoxyethylphosphine (1) with the omega-alkenylsilanes H2C=CH(CH2)(z)SiMem(OMe)(3-m) (2a-e). Treatment of [(eta(5)-C5Me5)RuCl](4) with the T-silyl phosphines 3a,b,d,e(TO) results in the formation of the c orresponding complexes (eta(5)-C5Me5)RuCl{MeOCH2CH2P[(CH2)(z)SiMem(OMe)(3-m )](2)}(2) [4a,b,d,e(T-0)]. In the presence of CH3CN and AgSbF6 4b(T-0) affo rds the cationic T-silyl complex [(eta(5)-C5Me5)Ru(NCCH3){MeOCH2CH2P[(CH2)( 6)SiMem(OMe)(3-m)](2)}(2)]+SbF6- [5b(T-0)]. 3a,b,d,e(T-0), 3c(D-0), 4a,b,d, e(TO), and 5b(TO) were sol-gel processed with variable amounts of the co-co ndensation agent (MeO)(2)MeSi(CH2)(6)SiMe(OMe)(2) (D-0-C-6-D-0) to give the stationary phases (Fn = functionality --> ligands or complexes) {Fn[SiOn/2 (OX)(3-n)](2)}{MeSiOi/2(OX)(2-i)(CH2)(6)(XO)(2-i)Oi/2SiMe}(y), Fn = P(CH2CH 2OMe)[(CH2)(z)-](2) 3a,b,d,e(T-n)(2)(D-i-C-6-D-i)(y) = I-1, II0-II4, IV1, V -1], {Fn[SiOi/2(OX)(2-i)Me](2)}{MeSiOi/2(OX)(2-i)(CH2)(6)(XO)(2-i)Oi/2SiMe} (4) [3c(D-i)(2)(D-i-C-6-D-i)(4) = III4], Fn = [Cp*RuCl](1/2)P(CH2CH2OMe)[(C H2)(z)-](2) [4a,b,d,e(T-n)(4)(D-i-C-6-D-i)(y) = VI1, VII0, VII1, VIII1, IX1 ], and Fn = {[Cp*Ru(NCCH3)]+SbF6-}(1/2)P(CH2CH2OMe)[(CH2)(6)-](2) [5b(T-n)( 4)(D-i-C-6-D-i)(4) = X-4] (see Table 1) [T = T-type silicon atom (three oxy gen neighbors); D = D-type silicon atom (two oxygen neighbors); n, i = numb er of Si-O-Si bonds; n = 0-3, i = 0-2; y = number of co-condensed DO-Cs-DO molecules]. Realistic amounts of T and D species and the degree of condensa tion were determined Si-29 CP/MAS NMR spectroscopically. The polymeric phos phines I-1, II0-II4, IV1, and V-1 show higher degrees of condensation than the corresponding ruthenium(II) complexes IV1, VII0, VII1, VIII1, and IX1. Bond lengths of the ruthenium(II) complex in the stationary phase VII0 were elucidated by an EXAFS analysis. From relaxation time studies (T-1P, T-1 rho H) smd cross-polarization exper iments (T-PH), it is concluded that the polymeric phosphines I-1, II0-II4, IV1, and V-1 reveal an increasing mobility with longer alkyl spacers betwee n the polymer and the P-functionality and an increasing amount of the co-co ndensation agent DO-Cs-DO. Owing to the multiple fixation of the ruthenium centers to the polymeric matrixes in the stationary phases VI1, VII0, VII1, VIII1, IX1, and X-4, the mobility in these materials is reduced. H-1,C-13- 2D-WISE NMR investigations on the interphase set up by X-4 and EtOH point t o a remarkable decrease of the rigid character compared to the stationary p hase X-4 without EtOH.