Solid-state photochemical [2+2] cycloaddition in a hydrogen-bonded metal complex containing several parallel and crisscross C=C bonds
Solid-state photochemical [2+2] cycloaddition in a hydrogen-bonded metal complex containing several parallel and crisscross C=C bonds
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DOI：
10.1002/chem.200701494
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发表时间：
2008-01-01
影响因子：
4.3
通讯作者：
Vittal, Jagadese J.
中科院分区：
文献类型：
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作者：
Peedikakkal, Abdul Malik Puthau;Vittal, Jagadese J.
一维氢键配合物[Zn（bpe）（2）（H2O）（4）]-（NO3）（2）中心点8/3 H（2）O中心点2/3bpe（1，bpe = 4，4 '-联吡啶基乙烯）的配位络合物阳离子[Zn（bpe）（2）（H2O）（4）]（2+）在固态下发生光化学[2+2]环加成反应，生成四（4-吡啶基）环丁烷（TPCB），产率高达100%，RCTT-TPCB（2a）为主要产物，RTCT-TPCB（2b）为次要产物。bpe配体的C = C键的十字形构象出现之前，光二聚化进行踏板状运动。将单晶研磨成粉末加速了bpe配体中交叉烯烃的踏板运动，使其平行排列，并定量地提供了rctt-环丁烷立体异构体2a。此外，100%的光二聚地面我表明，自由的bpe配体，这是远离彼此在一个水池中的水，和NO3-离子向对方移动，得到混合物的rctt-和rtct-tpcb异构体。
One-dimensional hydrogen-bonded complex [Zn(bpe)(2)(H2O)(4)]-(NO3)(2)center dot 8/3H(2)O center dot 2/3bpe (1, bpe = 4,4'-bipyridylethylene) containing coordination complex cations [Zn(bpe)(2)(H2O)(4)](2+) with parallel and crisscross double bonds undergoes photochemical [2+2] cycloaddition in the solid state and produces tetrakis(4-pyridyl)cyclobutane (tpcb) in up to 100% yield with rctt-tpcb (2a) as major and rtct-tpcb (2b) as minor product. The bpe ligands with crisscross conformation of C = C bonds appear to undergo pedal-like motion prior to photodimerization. Grinding single crystals to powder accelerates the pedal motion of crisscrossed olefins in the bpe ligands to parallel alignment and provides the rctt-cyclobutane stereoisomer 2a quantitatively. In addition, 100% photodimerization of ground I indicates that the free bpe ligands, which are remote from each other in a pool of water, and NO3- ions moved toward each other to give a mixture of rctt- and rtct-tpcb isomers.