Organosilane High Polymers: Thermochromic Behavior In Solution

Aliphatically substituted polydiorganosilylenes display reversible thermochromic behavior in solution with a bathochromic shift occurring with decreasing temperature. Solutions of polymers (RMeSi)n, R = n-propyl and n-hexyl, and poly(di-n-propylsilylene) show gradual bathochromic shifts of 16–25 nm from 92 to -67 °C. In polymers containing long di-n-alkyl substituents (n-alkyl = n-butyl, n-pentyl, and n-hexyl) the principal absorption band disappears as the temperature is lowered and a new band appears at 354 nm, giving a total red shift of up to 44 nm. The temperature dependence of the UV absorption maxima is thought to be due to conformational changes occurring along the polymer backbone with temperature. © 1985, American Chemical Society. All rights reserved.