Siloxane derivatives

Organosilicon diols of the disiloxane series can react with phosgene with cleavage of the siloxane and ether linkages occurring, in addition to the formation of the bischloroformates [793,1408]  

Organosilicon diols possessing ether linkages combine with phosgene to give a large spectrum of products (arising both by reaction with COClj and with HCl)  

ClSiMejCHjOCHjCHjOCOCl + 0(SIMejCHjOCOCl)j + (SiMe CHjCl)j + ClSiMejCHjCl + ClCH CHjCl + 

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Several siloxane derivatives T8[OSiMe2R]8 other than those mentioned in Sections V.F and V.G containing more complicated R groups, for example, R=(CH2)2CgH4-... 

Bis-pyrimidine derivatives were prepared by the reaction of the hydroxyethyl derivatives of pyrimidine with various bifunctional compounds such as dichloro-siloxane derivatives (Figure 3) (20). 

Matasumoto et al. have also reported a new family of silanols and siloxanes derived from thexyltrichlorosilane ThexSiCL 556 (Thex = 1,1,2-trimethypropyl).486,487 Depending on the applied conditions, the hydrolysis of 556 has afforded either ThexSi(OH)3 557 or Thex(OH)2SiOSi(OH)2Thex 558, both of which provide the silsesquioxane... 

Ohguma K et al. (2003) Synthesis of novel siloxanes derivatives containing reactive organic functional groups. Polym Prep Jpn (Soc Polym Sci Jpn) 52 1317... 

Additional polymerizable cyclic siloxane derivatives, (I), were prepared by the author [1] in a subsequent investigation. 

In summary (assuming maximum-possible surface coverage), all methyl siloxane derivatives have balanced coverage possibilities, whereas the three Ijo-octyl systems exhibit too much repellency, which would increase tremendously if they were extended to infinity. Thus, in reality, such pure Iso-octyl systems would not be formed at all. This tallies with results from hydrophobization experiments on dominating Iso-octyl derivatives that failed to perform adequately in special cases [73]. However, it was found, that catalytic effects may increase polycondensation [65]. 

Other interesting results pertain to 1,2- and 1,3-asymmetric inductions of C-allyl glycosides, homoallylic esters, and 4-methylene-US-dioxanes. The homologation with participation of an internal hydrosilane leads to cyclic siloxane derivatives. ... 

Marks and coworkers used a siloxane-derived hole-transport material, 4,4/-bis[(p-trichlorosilylpropylphenyl)phenylamino]biphenyl (TPD-Si2), to modify the ITO anode surface via formation of a self-assembly monolayer (SAM) [72]. Due to the close Ip of TPD-Si2 (5.5 eV) to the HOMO level of PFO (5.9 eV), the PFO-based device with ITO anode treated with TPD-Si2 SAM exhibited a maximum brightness and external quantum efficiency of 7000 cd m-2 and 0.35%, respectively, which were about two orders of magnitude larger than those for the bare ITO device (work function of ITO 4.7 eV). 

P. De Shong, M. E. Mowery, E. D. Soli, A. S. Manoso, M. C. Patterson, C. J. Handy, and M. -R. Brescia, Transmetalation in palladium-catalyzed cross-coupling and Staudinger imination reaction of glycosyl acceptors using hypervalent silane and siloxane derivatives, US Patent, US 6,414, 173 B1 (July 2, 2002) Chem. Abstr., 137 (2002) 63421. 

Two olefin epoxides, allylglycldylether and 4-vinylcyclohexene-oxide (VCHO), are commercially available to the extent that large scale production of their siloxane derivatives is feasiblet... 

Chart 11.2 Chemical structures of typical siloxane-derived monomers [21]. 

The presenee of two or more silicon atoms in different surroundings within the same moleeule enables to measure coupling constants "/( Si, Si) (k>1) by detection of the Si satellites in Si NMR spectra (see e.g. Fig. 9 for = 2 and an intervening sp -hybridised carbon). Important applications are obvious for siloxane derivatives or silicates (with Si enrichment), if it is possible to observe these two-bond eouplings for Si-O- Si units. 

Mandal, H. and Hay, A. S., Synthesis and Characterization by MALDI-TOF MS of Polycyclic Siloxanes Derived from p-Substituted Novolac Resins by MALDI-TOF MS, /. Polym. Sci Polym. Chem., 36, 2429, 1998. 

Saffarzadeh-Matin, S., Chuck, C.J., Kerton, F.M. and Rayner, C.M. (2004) Poly(dimethyl-siloxane)-derived phosphine and phosphinite ligands synthesis, characterization, solubility in supercritical carbon dioxide, and sequestration on silica. Organometallics, 23, 5176-81. 

Stiubianu, G., New Materials Developed with Lignocellulose Siloxane Derivatives. In Recent Developments in Silicone-Based Materials, Cazacu, M., Ed. Nova Science New York, 2010 pp 135-178. 

The polycondensadon between bisphenolic crar lexes and the siloxane derivative results in a dimeric or trimeric mixture containing only two Si-0 units, although the a,Ci)-... 

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