Hydrocarbon-Bridged Methyldimethoxysilanes as new Co-condensation Agents for the Sol-Gel Process of the Rhodium(I) Complex ClRh(CO)(P~O)2 Containing the Ligand PhP(CH2CH2
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- 作者：Ekkehard Lindner ; Theodor Schneller ; Hermann A. Mayer ; Helmut Bertagnolli ; Teja S. Ertel ; and Wolfgang Hö ; rner
- 刊名：Chemistry of Materials
- 出版年：1997
- 出版时间：July 1997
- 年：1997
- 卷：9
- 期：7
- 页码：1524 - 1537
- 全文大小：536K
- 年卷期：v.9,no.7(July 1997)
- ISSN：1520-5002
文摘
New hydrocarbon bridged co-condensation agents of thetypeMeSi(OMe)2(CH2)z(MeO)2SiMe[1(D0-Cz -D0),z = length of the flexible bridging group (z= 6, 8, 14)] were synthesizedand polycondensed to give the polysiloxanes1(Di -Cz -Di ).These monomers were employedin variable amounts y in the sol-gel processing of themonomeric ether-phosphine ligandPhP(CH2CH2OMe)(CH2)3Si(OMe)3[2(T0)] and itsP-coordinated trimethoxysilyl-(T)-functionalized rhodium(I) complexClRh(CO)(P~O)2[3(T0)2]to yield the polysiloxane-boundether-phosphine ligands2(Tn )(Di -Cz -Di )and the rhodium complexes3(Tn )2(Di -Cz -Di )y [O~P: 
1-P-coordinated ether-phosphine ligand;y = number of co-condensedD-Cz-Dmolecules; D = D-type silicon atom (two oxygen neighbors), T =T-type silicon atom (threeoxygen neighbors); i, n = number of Si-O-Sibonds; i = 0-2; n = 0-3]. Therelative amountsof T and D silyl species and the degree of condensation were determinedby 29Si CP/MASNMR spectroscopic investigations. The polysiloxanes1(Di -Cz -Di )which are regarded as"organofunctionalized Q analogues" display a higher degree ofcondensation than their Qcounterpart [Q = Q-type silicon atom (four oxygen neighbors)].The highest degrees ofcondensation of the D groups were obtained for theD-C14-D polymer and the F-T/D-C14-D copolymers [F =(Ph)P(CH2CH2OMe)(CH2)3-(2),[ClRh(CO)]1/2(Ph)P(CH2CH2OMe)(CH2)3- (3)]. 31Pand 13C CP/MAS NMR spectroscopic studies give evidence thatthe ligandand the geometry of the complex is preserved during the entiresol-gel process. In additionan EXAFS spectroscopic analysis of the complex3(Tn )2gave a more detailed description ofits structure. 31P CP/MAS NMR relaxation time studies(T1P, TPH,T1
H), 2D WISENMRexperiments, and the line widths of the 31P CP/MAS NMRspectra were applied for dynamicinvestigations. The noncomplexed ether-phosphine ligand in theF-T/D-Cz-D copolymersis more mobile than that in the F-T/Q copolymer2(Tn )(Qk )2[k = number of Si-O-Si bonds;k = 0-4]. The P-coordination of only twoether-phosphines in the complex leads to anadditional cross-linking in the matrixes. Thereby the ligandsbecome more rigid due to strongphosphorus-rhodium bonds.
1-P-coordinated ether-phosphine ligand;y = number of co-condensedD-Cz-Dmolecules; D = D-type silicon atom (two oxygen neighbors), T =T-type silicon atom (threeoxygen neighbors); i, n = number of Si-O-Sibonds; i = 0-2; n = 0-3]. Therelative amountsof T and D silyl species and the degree of condensation were determinedby 29Si CP/MASNMR spectroscopic investigations. The polysiloxanes1(DH), 2D WISENMRexperiments, and the line widths of the 31P CP/MAS NMRspectra were applied for dynamicinvestigations. The noncomplexed ether-phosphine ligand in theF-T/D-Cz-D copolymersis more mobile than that in the F-T/Q copolymer2(T