NMR study of the PPV conducting polymers

Summary form only given. I/sub 2/-doped Poly(2-butoxy-5-Methoxy-1,4-Phenylenevinylene) (PBMPV) has been studied by the techniques of pulsed /sup 1/H nuclear magnetic resonance (NMR). With increasing degree of the doping and thus the electrical conductivity, changes in the microscopic environment were reflected in the NMR measurements. The NMR linewidth decreased considerably with the slightest doping. However, thereafter, it generally increased with increasing degree of doping. The heavily doped samples show two peaks, suggesting two different sites. The spin-lattice relaxation rate generally increases with the degree of doping, suggesting that the relaxation mechanism becomes more effective with heavier doping. The heavily doped samples exhibit a double exponential type spin-lattice relaxation, with two time constants. This is in agreement with the lineshapes showing two peaks.