About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Abstract
Poly(di-n-pentylsilane) has been previously reported to adopt a 7/3 helical conformation at room temperature. We have studied the solid state structure of a low molecular weight (Mw = 46 000) sample and its dependence on temperature using wide angle X-ray diffraction, differential scanning calorimetry, and Raman spectroscopy. The results suggest that domains of two distinct structures are present, one having an all-trans conformation and the other a 7/3 helical conformation. The all-trans conformation was observed (even at room temperature) in samples cooled previously to -15 °C. Characteristic resonance enhancement of certain Raman vibrations is observed for the planar zigzag polymorph. The all-trans material converts to the 7/3 helical structure at 35 °C and subsequently undergoes an order/disorder transformation at about 56 °C. © 1994, American Chemical Society. All rights reserved.