Polystannanes electronic properties

The polysilanes can be regarded as one-dimensional analogs to elemental silicon, on which, of course, nearly all of modem electronics is based. The photophysical behavior of polysilanes is not approached by any other materials, save for the less stable and more costly polygermanes and polystannanes. The remarkable properties of polysilanes have led to intense interest, and to numerous proposed high-tech applications. But the great promise of polysilanes as materials has yet to be realized. Their only commercial use at present is as precursors to silicon carbide ceramics, an application which takes no advantage of their optical or electronic properties. 

Most of the reactions that can be used to prepare distannanes can be extended to the preparation of oligo- and polystannanes, which have attracted interest for potential use in electronic and optical devices.455 The structures of the products are not necessarily those of completely linear catenanes, (R2Sn) , and different degrees of branching confer different properties. The formation of polymers is also frequently accompanied by the formation of cyclic pentamers or hexamers, and samples prepared by different methods may show substantially different properties. 

US6S. Both polygermanes and polystannanes may find applications because of their unique optical, electronic, and chemical properties. Some of these potential uses include photoresist layers (44,59,60), third-order nonlinear optical materials (50), charge transport polymers (61,62), photoconductors, microlitho-graphic materials (63), and photoinitiators (59). 

We have found that if the thermolysis of the cyclotristannane 1 is carried out with benzophenone at 200° C, two new polycyclic polystannanes, 7 and 8, which are members of the perstanna-[n]-prismane, [RSn]2n, series of compounds, can be isolated by column chromatograpy in a 1 2.3 ratio for a combined yield of 12% [11,12]. Since the octastanna-[4]-prismane 7 and the decastanna-[5]-prismane 8 display different physici and chemical properties, an investigation of these compounds reveals important information concerning the impact that bond angle distortions have on the electronic structure and thermodynamic stability of heavy atom Group IVA polycyclic compounds. 

RSn]2o will be that of the dodecastanna-[10]-prismane rather than that of dodecastanna-dodecahedron. Currently, work is in progress to substantiate these views and the molecular and electronic structures of the new polycyclic polystannanes which are discovered in the process will undoubtedly help to formulate our ideas concening the factors which govern the i ysical and chemical properties of Group IVA heavy atom M-M bonded netwoiks. 

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