Crystal structure and photoreactivity of a halogen-bonded cocrystal based upon 1,2-diiodoperchlorobenzene and 1,2-bis(pyridin-4-yl)ethylene
Crystal structure and photoreactivity of a halogen-bonded cocrystal based upon 1,2-diiodoperchlorobenzene and 1,2-bis(pyridin-4-yl)ethylene
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DOI：
10.1107/s2053229620006233
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发表时间：
2020-06-01
影响因子：
0.8
通讯作者：
Groeneman, Ryan H.
中科院分区：
文献类型：
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作者：
Bosch, Eric;Battle, Jessica D.;Groeneman, Ryan H.
以1，2-二碘全氯苯（1，2-C_6I_2Cl_4）和反式-1，2-二（吡啶-4-基）乙烯（BPE）为原料，合成了一种光反应共晶。所得共晶2（1，2-C6 I2Cl 4）中心点（BPE）或C6 Cl 4 I2中心点0.5C（12）H（10）N（2）包含通过I中心点中心点N卤素键和卤素-卤素接触的组合保持在一起的组分的平面片。值得注意的是，1，2-C6 I2Cl 4分子以均匀和面对面的取向π堆叠，这导致卤素键供体的无限柱。由于这种堆叠排列和I中心点N卤素键，BPE分子也以这种类型的图案堆叠。特别是，相邻的乙烯基在BPE被发现是平行的，并在可接受的距离内的光反应。在暴露于紫外光下时，共晶经历固态[2 + 2]环加成反应，以89%的总收率产生rct-四（吡啶-4-基）环丁烷（TPCB）。利用组分的干涡旋研磨的无溶剂方法也导致具有类似产率的光反应性材料。
The formation of a photoreactive cocrystal based upon 1,2-diiodoperchlorobenzene (1,2-C6I2Cl4) and trans-1,2-bis(pyridin-4-yl)ethylene (BPE) has been achieved. The resulting cocrystal, 2(1,2-C6I2Cl4)center dot(BPE) or C6Cl4I2 center dot 0.5C(12)H(10)N(2), comprises planar sheets of the components held together by the combination of I center dot center dot center dot N halogen bonds and halogen-halogen contacts. Notably, the 1,2-C6I2Cl4 molecules pi-stack in a homogeneous and face-to-face orientation that results in an infinite column of the halogen-bond donor. As a consequence of this stacking arrangement and I center dot center dot center dot N halogen bonds, molecules of BPE also stack in this type of pattern. In particular, neighbouring ethylene groups in BPE are found to be parallel and within the accepted distance for a photoreaction. Upon exposure to ultraviolet light, the cocrystal undergoes a solid-state [2 + 2] cycloaddition reaction that produces rctt-tetrakis(pyridin-4-yl)cyclobutane (TPCB) with an overall yield of 89%. A solvent-free approach utilizing dry vortex grinding of the components also resulted in a photoreactive material with a similar yield.