Facile synthesis of linear poly(dibutylstannane)

Abstract

We present a facile, high-yield synthetic route to linear poly(dibutylstannane) of relatively high molecular weight (M w = 20 6 10 3 g mol 21 ) through dehydropolymerization of dibutylstannane with the catalyst [RhCl(PPh 3 ) 3 ]. Unlike previously synthesized polystannanes, the present materials were entirely free of cyclic oligomers. A reversible phase transition was observed at a temperature of y1 uC, which was found to be associated with a marked change in crystalline order. The material appeared to be in a liquid-crystalline-like state at room temperature and could be readily oriented by simple shearing processes, which resulted in highly ordered films.

Oriented Poly(dialkylstannane)s

“…Hence, orientation was induced by shearing, which has been previously successfully applied for poly(dibutylstannane) taking advantage of its liquid-crystalline state at room temperature. [2,3,23] It was attempted to also orient poly(dioctylstannane) and poly(didodecylstannane) by shearing onto glass slides, not only at room temperature, but also at 40 8C for poly(dioctylstannane) and 60 8C for poly(didodecylstannane). At these temperatures these materials are without order, as opposed to their liquid-crystalline lamellar structure at room temperature.…”

“…[1][2][3][4][5][6][7][8][9][10] These polymers, which typically are of the composition (-SnR 2 -) n and termed polystannanes, are structurally related to corresponding polymers with the semi-metals silicon or germanium (i.e., elements that are located in the periodic table in the same group as tin) and are of potential interest as semiconductors. [11][12][13] However, the synthesis of linear polystannanes in high yield and free of cyclic oligomers has been achieved only recently [2,3] and, therefore, until now the properties of polystannanes have been relatively little explored.…”

“…A variety of techniques have been developed to induce orientation of polymer molecules, which is crucial to investigate and exploit the anisotropic mechanical, optical, and electronic properties of the macromolecules. Orientation by shearing, [2,19] as well as solid-state drawing, is suited if the mechanical behavior of the polymer permits large elongation. Also, polymers have been (co)-oriented with the assistance of a matrix polymer that was subjected to tensile deformation.…”

From poly(dialkylstannane)s to poly(diarylstannane)s: comparison of synthesis methods and resulting polymers

“…4 that the residual mass is clearly below the mass fraction of tin in the polymer (4, 51%; 3, 47%; 1, 43%; 2, 31%); this can be explained by formation of volatile organotin compounds at elevated temperatures. Differential scanning calorimetry revealed the previously described phase transition of 4, [1] while no phase transition was observed between −50 and 200…”

“…Recently, facile synthesis routes were developed for poly(dialkylstannane)s [1] and poly[bis-(ω-phenylalkyl)stannane]s. [2] Thereby, dialkylstannanes are polymerized in the presence of a transition metal catalyst. Using chloridotris(triphenylphosphine)rhodium(I) by dehydrogenation we received linear polymers that can be isolated in high yields.…”