Ring-opened Crystal Structure and Photochromism of 2,2-Bis(4-tertiary butyl phenyl)-3H-naphtho[2,1-b]pyran
The title compound, 2,2-bis(4-tertial butyl phenyl) naphthopyran, has been prepared and characterized by means of IR, 1H NMR and elemental analysis, and its crystal structure was determined with X-ray diffraction in the ring-opened form after hydrolyzation. It belongs to monoclinic, space group P21/c, with a = 14.358(3), b = 7.6725(15), c = 24.470(5) A,, β= 97.147(4)°, C33H36O2, Mr = 464.62, V = 2674.8(9) A3, Z = 4, Dc = 1.154 g/cm3,μ = 0.070 mm-1, F(000) = 1000, the final R = 0.0514 and wR = 0.1272 for 5444, observed reflections (I > 2σ(Ⅰ)). X-ray analysis revealed that the C(13)-O(1) bond of the title compound cracks after UV irradiation, the six-membered heterocycles are destroyed, and zwitterionic intermediates come into being. The molecular structure in the ring-opened form is obtained after hydrolyzation. It is infrequent that the single-crystal structure is determined in a ring-opened form. A two-dimensional framework is formed by O-H…O and Car-H…O hydrogen bonds. The UV-vis spectca show that the title com-pound exhibits excellent photochromic properties in solutions and polymers.
作 者： TAN Ting-Feng PANG Mei-Li WU Bian-Peng 作者单位： TAN Ting-Feng,WU Bian-Peng(Department of Materials Science & Engineering,Tianfin Institute of Urban Construction,Tianjin 300384,China)PANG Mei-Li(Department of Chemistry,Nankai University,Tianfin 300071,China)
刊 名： 结构化学 ISTIC SCI PKU 英文刊名： CHINESE JOURNAL OF STRUCTURAL CHEMISTRY 年，卷(期)： 2009 28(2) 分类号： O6 关键词： naphthopyran ring-opened form crystal structure photochromism