No abstract

A new methodology for the preparation of air-stable boron-containing polymers by the polyaddition between dicyano compounds and t-BuBH2'NMes (1) is described. The polyaddition between Í and isophthalonitrile (2a) was carried out in diglyme under some varied conditions. The molecular weight of the resulting polymer (3a), estimated by GPC, increased when a small excess amount of 1 was used for this polymerization. The structure of 3a was confirmed by , 13C, and UB NMR, UV, and IR analyses. The stability of 3a against air and moisture as well as its thermal stability was examined. The boron-containing polymer 3a was found to be stable under air and moisture. As dicyano compounds, telephthalonitrile (2b), l,5-bis(4,4'-cyanophenoxy)pentane (2c), and , -dicyanoalkanes (2d-f) were also used in the present hydroboration polymerization. Among these compounds, the monomers having aromatic cyano groups gave polymers with higher molecular weights.

NLO-chromophores of the azobenzene type and of the stilbene type have been used either as dopants or as sidegroups in polymers in order to realize NLO-materials in which the refractive index and the nonlinear susceptibility could be modified optically.1,2 These changes are based on the photochemical transformation of these molecular units from the elongated trans state to the bent cis-state. Since the trans state is the thermodynamically stable state, the cis-isomers generally undergo a thermally activated relaxation back to trans even below the glass transition temperature.3