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通过反 1 (4 联苯基) 2 (4 吡啶基)乙烯(E I)在稀硫酸中的光二聚反应合成了r 1,c 2,t 3,t 4 1,3 双(4 联苯基) 2,4 二(4 吡啶基)环丁烷(II).用X射线衍射法测定了其结构.晶体II为单斜晶系,空间群为P21/n,晶胞参数:a=1.0038(2),b=1.8995(4),c=1.4647(3)nm,β=98.82(3)°,晶胞内分子数为4.在II的分子中,其四元环呈蝶式构象.研究发现,在短波紫外光照射下,II容易发生光解开环反应生成其反式单体E I,随后新生成的E I经反顺异构化反应转变为其顺式异构体(Z I),最后反顺异构化反应达到平衡.光解II或E I得到同样的反顺异构体混合物.
In the present work, r 1, c 2, t 3, t 4 1,3-bis (4-biphenylyl) biphenyl were synthesized by photodimerization of 1 (4-biphenylyl) Its structure was determined by X-ray diffraction. The crystal II was monoclinic with the space group of P21 / n. The unit cell parameters were a = 1.0038 (2) ), b = 1.8995 (4), c = 1.4647 (3) nm, β = 98.82 (3) °, and the number of intracellular unit is 4. In the II molecule, the four-membered ring has a butterfly conformation. , It is easy for photolysis and ring-opening reaction of II to generate its trans-monomer EI under the irradiation of short-wave ultraviolet light. Subsequently, the newly formed EI is transformed into its cis-isomer (ZI) by the anti-isomerization reaction and finally the anti- The isomerization reaction is equilibrated and photolysis II or EI gives the same cis-isomer mixture.