High molecular mass polystannanes via dehydropolymerization of di(n-butyl)stannane

Abstract

The dehydropolymerization of BunnSnH2, catalysed by [Zr(C5H5)(C5Me5){Si(SiMe3)3}Me], produces cyclic (SnBun2), oligomers and long H(SnBun2),H polystannane chains (MJM, = 17 500/7800), which exhibit a long-wavelength electronic absorption (Amax = 382 nm) and emit green light (Amax = 505 nm; 337.1 nm excitation).The recent discovery and rapid development of polysilane high polymers can be attributed largely to the interesting electronic properties which these materials possess. 1 Polysilanes exhibit a strong near-UV absorption that results from o-conjugation along the silicon backbone. The radiation-sensitivity associated with excitation of this transition makes these polymers suitable for applications in microlithography .Also, owing to their delocalized electronic structure and relatively narrow band gap (ca. 4 eV), polysilanes provide a new class of photoconducting and charge-transporting poly-

Light‐Stability of Poly(dialkylstannane)s

“…Note that the molar mass of polystannanes might decrease somewhat upon redissolution, [10] and accordingly a moderate difference in the degradation rate might result upon exposure of solutions containing in situ synthesized or redissolved polystannanes; see, for instance, the stability factors F in Table 4 and 5 for the degradation of poly(dibutylstannane) in CH 2 Cl 2 according to both methods, where F amounted to 0.43 and 0.57, respectively. It should be noted that poly(dialkylstannane)s exhibit a strong UV absorption band with an absorption maximum in the region of 370-410 nm, [7,9,13,14,[16][17][18][19] which presumably arises from the delocalization of s-electrons of the tin atoms along the polymer backbone. In several reports, this band was used for the analysis of the degree of degradation of polystannanes.…”

“…In several reports, this band was used for the analysis of the degree of degradation of polystannanes. [7,[17][18][19] However, as polystannanes are sensitive to light, some degradation might be induced by the light employed for the UV-Vis measurements. We investigated the extent of this degradation with poly-(dibutylstannane), poly(dioctylstannane), and poly(didodecylstannane) in toluene solutions at a concentration of ca.…”

Organotin Polymers

“…Polystannanes have been generally synthesized using one of four methods: [235][236][237][238][239] reductive coupling, dehydrogenative coupling, "masked" dienes, and anionic ring opening. Many of these materials show better sigma conductivity than the corresponding polysilanes and have been used as light-emitting diodes.…”

Oriented Poly(dialkylstannane)s

“…[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.…”