Skip to main content Accessibility help
×
Home

Molecular Origins of the Unique Conformational Properties of the Polysilanes: A Molecular Dynamics Study of Poly(Di-N-Hexylsilane)

  • William J. Welsh (a1), Samuel H. Tersigni (a1) and Wangkan Lin (a1)

Abstract

The conformational dynamics of a model compound for poly(di-n-hexylsilane) (PDHS) has been explored using the new molecular dynamics program MM3-MD. MM3-MD trajectories at variable temperatures reveal two abrupt conformational transitions, one near -182°C and another near -175°C, associated with two energy barriers on the potential-energy surface. The first transition near -182°C allows shifts in the backbone torsion angle from that defined by the global energy minimum designated off-trans to that corresponding to a statistical collection of torsion angles within the range trans ±30°. The second transition near -175°C allows the backbone torsion angle to explore the remainder of its torsional space. The sidechain dynamics follows a similar pattern. We suggest that the abrupt transition calculated here at -182°C for “gas.phase” PDHS corresponds to that observed for PDHS at -28°C in solution and at 42°C in the solid state.

Copyright

References

Hide All
1. For reviews on the polysilanes, see: (a) West, R. in The Chemistry of Organic Silicon Comoounds, edited by Patai, S. and Rappoport, Z. (John Wiley & Sons, New York, 1989), p. 1208; (b) R.D. Miller and J. Michl, Chem. Rev. 89, 1349 (1989); (c) J.M. Zeigler, Synth. Met. 28, C581 (1989); Silicon-Based Polymer Science: A Comprehensive Review, edited by J.M. Zeigler and F.W. Fearon (Adv. in Chem. Ser. 324, American Chemical Society, Washington, D.C., 1990).
2. MM3-MD, a dynamics program written by Li, F., Cui, W., Lin, W., Allinger, N.L., and Welsh, W.J..
3. Allinger, N. L., Yuh, Y.H., and Li, H.-H., J. Am. Chem. Soc. 111, 8551 (1989).
4. (a) Tersigni, S.H., Ritter, P., and Welsh, W.J., J. Inorg. Organomet. Poly. 1, 377 (1991); (b) W.J. Welsh, in Inorganic and Metal-Containina Polymeric Materials, edited by J. Sheats, C. Carraher, M. Zeldin, B. Currell, and C. Pittman, Jr. (Plenum, New York, 1990), p. 197; (c) W. Lin, S.H. Tersigni, and W.J. Welsh, Comput. Polym. Sci. 1, 225 (1991); (d) S.H. Tersigni and W.J. Welsh, Comput. Polym. Sci. 2, (in press).
5. Schweizer, K.S., J. Chem. Phy. 85, 1156 (1986); 85, 1176 (1986); Synth. Metals 28, C565 (1989).
6. Schweizer, K.S., Harrah, L.A., and Zeigler, J.M., in Silicon-Based Polymer Science: A Comorehensive Resource, edited by Zeigler, J.M. and Fearon, F.W. (Adv. in Chem. Ser. 324, American Chemical Society, Washington, D.C., 1990), p. 379.
7. Kirtman, B. and Hasan, M., J. Chem. Phys. 96, 470 (1992).

Molecular Origins of the Unique Conformational Properties of the Polysilanes: A Molecular Dynamics Study of Poly(Di-N-Hexylsilane)

  • William J. Welsh (a1), Samuel H. Tersigni (a1) and Wangkan Lin (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed