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Crystal structures of N(p-phenoxy-phenyl) maleimide and N(p-phenoxy-phenyl) methacrylamide

In the course of our research on the preparation and characterization of alternating copolymers of comb-like structure, we prepared N(p-phenoxy-phenyl) maleimide (PhOPhMI) and N(p-phenoxy-phenyl) methacrylamide (PhOPhMAA) as electron acceptor comonomers. Both monomers readily copolymerize in toluene or dioxane in the presence of azobisisobutyronitrile (AIBN) as initiator, but, as expected, the rigid PhOPhMI polymerizes much faster than the flexible monomer PhOPhMAA. In order to get a better insight into the structural features and mechanism of solid-state high energy radiation-induced polymerization of monomers PhOPhMI and PhOPhMAA, we determined the crystal structure of both monomers. The crystals of PhOPhMI belong to the monoclinic space group P2, with a = 0,6551(5)Á, b = 12,172(5) Á, c = 0,8763(5) Á, ? = 111,560(5)0, V = 649,9(7) Á3, Z = 2 and Dcalc = 1,356 g cm-3 , while the crystals of PhOPhMAA are orthorhombic, space group Pbca, with a = 9,191(2)Á, b = 11,309(3) Á, c = 26,917(8) Á, V = 2797,8(13) Á3, Z = 3 and Dcalc = 1,203 g cm-3. The analysis showed that both molecular structures are the best described in terms of three planes: two phenyl ring planes and the planes through five- membered maleimide or methacrylamide residues. The angles between two phenyl ring planes amount to 89,68(8)0 in PhOPhMI and 78,83(13)0 in PhOPhMAA, while those between the planes through the central phenyl rings and the maleimide and methacrylamide residues are 53,74(9)0 and 70,44(17)0, respectively.

crystal structure; N(p-phenoxy-phenyl) maleimide; N(p-phenoxy-phenyl) methacrylamide; rate of homopolymerization

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