Novel D- and T-functionalized Polysiloxane Matrices for Reactions in Interphases

Lindner, Ekkehard; Salesch, Thomas; Hoehn, Frank; Mayer, Hermann A.

doi:10.1002/(sici)1521-3749(199912)625:12<2133::aid-zaac2133>3.0.co;2-7

Cited by 10 publications

(4 citation statements)

References 14 publications

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“…Owing to the high portion of organic components in these stationary phases, surface area measurements according to the BET method reveal low values (<10 m 2 g -1 ), which are in agreement with materials of this type. 33c,, …”

Section: Resultssupporting

confidence: 68%

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones¹^,²

Lindner

Mayer

et al. 2005

Chem. Mater.

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Diphenyldiphosphinopropane 4T 0 , provided with a T0-silyl functionalized (CH2)6-spacer in the symmetric 2-position of the C3 bridge, was obtained via an improved synthetic route in high yields, starting from 8-chloro-7-chloromethyl-1-octene (1) (Scheme ). Reaction of 4T 0 with trans-RuCl2(NBD)Py2 in CH2Cl2 resulted in the formation of the corresponding (diphos)ruthenium(II) complex 5T 0 (Scheme ), which, by treatment with 1,2-diaminopropane, was transformed to the T0-silyl functionalized diamine(diphosphine)ruthenium(II) complex 6T 0 . In the presence of four different amounts of the co-condensation agent MeSi(OMe)3, 6T 0 was subjected to a sol−gel process (Scheme ). The resulting inorganic/organic hybrid materials X1 − X4 [6T 0 /MeSi(OMe)3 = 1:10/15/20/50] were characterized by 31P and 29Si solid-state NMR and EXAFS spectroscopy, as well as by EDX and BET measurements. It was confirmed that the integrity of the organometallic centers in X1 − X4 is maintained compared to the monomeric counterpart 6T 0 . The materials X1 − X4 proved to be catalytically active in the direct hydrogenation of the model substrate trans-4-phenyl-3-butene-2-one. With a conversion rate of 100% and a selectivity to the alcohol A (Scheme ) of approximately 91%, the interphase catalyst X1 showed the best performance. It could be recovered eight times without detectable leaching and remarkable deactivation. The catalytic activities of X1 and monomeric 6T 0 were compared with each other.

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Section: Resultssupporting

confidence: 68%

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones¹^,²

Lindner

Mayer

et al. 2005

Chem. Mater.

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“…As a result of the T 1rH measurements in the solid state the formation of domains is excluded, which means that the materials are homogeneous. 1 evidence that the xerogels form highly mobile interphases if solvents of medium polarity like chloroform or tetrahydrofuran are used. Due to a lower degree of condensation the polymers with T-silyl functions seem to be more mobile in the solid and in suspension than the pure D-polymers.…”

Section: Discussionmentioning

confidence: 99%

“…1. The 29 Si signals of these copolymers are in the typical range for R 2 Si (R~Me, Et), D-, T-and T Ph -silyl functions and their substructures D 0 -D 2 , T 0 -T 3 and T 1 Ph -T The degree of condensation of the D-, T-and T Ph -species and the real ratios of T Ph : D and T Ph : T (Table 2) were determined by generally known methods. 21,29,30 The degrees of condensation range between 70 and 96% for the D-functions and 52 and 70% for the T-groups.…”

Section: Solid State Nmr Spectroscopic Investigationsmentioning

confidence: 99%

Investigations on the mobility of novel sol–gel processed inorganic–organic hybrid materials

et al. 2001

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Novel co-condensing agents of the type R'Si(OMe) 2 (CH 2 ) 3 R 2 Si(CH 2 ) 3 Si(OMe, R~Et, R'~OMe} were synthesised by hydrosilylation of the corresponding diallyldialkylsilanes 1, 2 with dichloro(methyl)silane and trichlorosilane, respectively, followed by treatment with trimethyl orthoformate. These precursors were sol-gel processed with or without PhSi(OMe) 3 [Ph(T 0 )] to give the xerogels X3a-d, X4a-d. The polysiloxane matrices, the degree of condensation and the integrity of the hydrocarbon backbone were investigated by means of solid state NMR spectroscopy ( 13 C, 29 Si). To study the polymer dynamics in the dry state 29 Si CP/MAS NMR measurements of relaxation times (T 1rH ) and crosspolarisation parameters (T SiH ) were carried out. 1 H HR/MAS NMR experiments and T 1rH measurements in different solvents were undertaken to get information on the mobility of the polymers in suspension. Scanning electron microscopy (SEM) images show the morphology of the polymers and energy dispersive X-ray spectroscopy (EDX) suggests that the distribution of the elements agrees with the applied stoichiometry.

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“…The spacers not only differ in their lengths but also vary in their shape and polarity (alkane, PEG). The backbones of the polysiloxane matrices are build by simple cocondensing agents such as Me 2 (SiOMe) 2 (D-type), Me(SiOMe) 3 (T-type), and Si(OMe) 4 (Q-type) (Figure ) as well as by specially designed cocondensing agents [H 3 C(MeO) 2 Si(CH 2 ) z Si(OMe) 2 CH 3 , H 3 C(MeO) 2 Si(CH 2 ) z (C 6 H 4 )(CH 2 ) z Si(OMe) 2 CH 3 , (quasi Q-type)]. ,, The cocondensing agents are the components which modulate the stationary phase from rigid to highly mobile. They are also responsible for the porosity and swelling ability of the materialsthese effects are a function of the degree of cross-linking within the polymer matrix.…”

Section: Introductionmentioning

confidence: 99%

Neural Networks Evaluating NMR Data: An Approach To Visualize Similarities and Relationships of Sol−Gel Derived Inorganic−Organic and Organometallic Hybrid Polymers

Hoehn¹,

Lindner²,

Mayer³

et al. 2002

J. Chem. Inf. Comput. Sci.

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An artificial neural network (ANN)--the Kohonen Self-Organizing Feature Map (SOM)-is used to evaluate solid-state NMR spectroscopic derived data of 72 siloxane-based phosphine and organometallic functionalized hybrid polymers. The data set consists of parameters that describe their structural features and their dynamic behavior. The ANN visualizes similarities of the investigated compounds by reducing the dimension of the data set. This allows a comparison of these polymers that was not possible beforehand because of their structural diversity.

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Novel D- and T-functionalized Polysiloxane Matrices for Reactions in Interphases

Cited by 10 publications

References 14 publications

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones¹^,²

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones¹^,²

Investigations on the mobility of novel sol–gel processed inorganic–organic hybrid materials

Neural Networks Evaluating NMR Data: An Approach To Visualize Similarities and Relationships of Sol−Gel Derived Inorganic−Organic and Organometallic Hybrid Polymers

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Novel D- and T-functionalized Polysiloxane Matrices for Reactions in Interphases

Cited by 10 publications

References 14 publications

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones1,2

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones1,2

Investigations on the mobility of novel sol–gel processed inorganic–organic hybrid materials

Neural Networks Evaluating NMR Data: An Approach To Visualize Similarities and Relationships of Sol−Gel Derived Inorganic−Organic and Organometallic Hybrid Polymers

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Product

Resources

About

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones¹^,²

Sol−Gel Processed Diamine(diphosphine)ruthenium(II) Complexes for the Catalytic Hydrogenation of α,β-Unsaturated Ketones¹^,²