Organotin condensation polymers

A comment needs to be made on the yields of reactions. Indeed, hydrolysis-condensation reactions can yield well-defined organotin oxo-clusters, but they can also yield ill-defined organotin oxo-polymers. 

Following are microorganisms that have been successfully inhibited by condensation organotin-containing polymers including organotin polyamines. 

Schreiber and co-workers (436) prepared a library calculated to contain 2.18 million polycyclic compounds through the 1,3-dipolar cycloaddition of a number of nitrones with alkenes supported on TentaGel S NH2 resin (Scheme 1.83). (—)-Shikimic acid was converted into the polymer bound epoxycyclohexenol carboxylic acid 376 (or its enantiomer), coupled to the resin via a photolabile linker developed by Geysen and co-workers (437) to allow release of the products from the resin in the presence of live cells by ultraviolet (UV)-irradiation. A range of iodoaromatic nitrones (377) was then reacted with the ot,p-unsaturation of the polymer-bound amide in the presence of an organotin catalyst, using the tandem esterification/ dipolar cycloaddition methodology developed by Tamura et al. (84,85) Simultaneous cyclization by PyBrop-mediated condensation of the acid with the alcohol... 

Polycondensates with the Ligand as a Comonomer. Metal-bearing polycondensates in which the ligand moiety alone or in combination with the coordinated metal ions form one of the backbone comonomers are exemplified by the following polymers reported by Wudl et al [48], Biswas and Mazumdar [49, 50] and by Takahashi et al. [51] in the synthesis of organotin polymer by a similar condensate (Figs. 20, 21). 

The preparations of several organometallic polymers are given here for reference to some more common types of polymers. They are the vinyl type, complex metal phthalocyanines, organotin hydride-olefin condensations, and the poly(metal phosphinates). More detailed reviews on organometallic pol3oners should be consulted for additional information [1,2]. 

The organotin halide chosen for most of this study was dibutyltin dichloride because of its low cost relative to other organotin halides and the observation from previous studies that other polymers, namely cellulose, and polyvinyl alcohol, which were modified through condensation with dibutyltin dichloride, showed good activity against a number of fungi tested. ... 

Labadie et synthesized a munber of organotin polymers and reported their resist properties. These products included homopolymers of stannylalkyl methacrylates that crosslinked upon e-beam exposme. It is interesting that copolymers containing methyl methacrylate units degraded on e-beam exposure. Polymers containing tin in the backbone were prepared by condensation of aminostannanes with a,03-diynes followed by crosslinking upon e-beam exposure. A 15 wt % tin content was required to obtain etch rate selectivities of > 15 1 relative to the corresponding non-tin polymer. 

Fig. 12, Silanol polycondensation. A hydrosgrl-terminated PDMS polymer chain reacts with an ethyl silicate (PDES) in the presence of an organotin catalyst. The reaction results in a crosslinked network and releases ethanol as a condensation product.

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