Preparation of functional polymers from 1,3-diacetylenes

Abstract

Poly(1-phenylpenta-1,3-diyn-5-ol) (PPDO), prepared by $NbCl_5$/$(n-Bu)_4Sn$ catalysed metathesis of PDO, was converted into a graphite-like structure with high electrical conductivity in the absence of dopants by heat treatment at $800^\circ C$ under vacuum. Poly(2,4-hexadiyn-1,6-diol) (PHDO), prepared by $NbCl_5$/$(n-Bu)_4Sn$ catalyzed metathesis of HDO, was pyrolyzed at various temperatures and electrical and structural properties of resulting polymers were investigated by FT-IR, Laser Raman, CP/MAS $^{13}C$-NMR and X-ray diffraction methods. The polymer obtained by pyrolysis of PHDO at $800^\circ C$ showed a conductivity of about 10 S/cm at room temperature. The structure of the polymer seems to be a graphite-like crystal consisting of condensed aromatic layers. Poly[1-(2-methoxyphenyl)penta-1,3-diyn-5-ol] [(1,2)-PMDO] was prepared by $NbCl_5$/$(n-Bu)_4Sn$ catalyzed metathesis of (1,2)-MDO followed by spin-casting from MC solvation. Thin films of resulting polymers were pyrolyzed at various temperatures. UV, IR, and Raman spectroscopies were employed to investigate the chemical structure of the films during pyrolysis. The electrical conductivity of films can be varied over several decades by changing the final temperature of cabonization. Poly[1-(2-methoxyphenyl)penta-1,3-diyn-5-ol] [(1,2)-PMDO], was prepared by $NbCl_5$/$(n-Bu)_4Sn$ catalyzed metathesis. The 2:3 (1,2)-PMDO/PMMA (w/w) film showed a conductivity of about $10^{-3}$ S/cm after $FeCl_3$ doping. Third order nonlinear optical susceptibility ($\chi^3$) of (1,2)-PMDO, evaluated from third harmonic generation by Maker fringe method, showed $1.03\,\times\,10^{-13}$ esu. 2,4-Hexadiyn-1,6-diol (HDO) was polymerized on a glass and silicon plate by chemical vapor deposition without transition metal catalyst to form a homogeneous thin film. Structural properties of the films were investigated by FT-IR, UV-visible, fluorescence, X-ray diffraction, and XPS spectroscopic analyses. The CVD-polymerized HDO (CVD...