Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
Rigaku Americas Corporation, 9009 New Trails Drive, The Woodlands, TX 77381, USA.
Molecules. 2022 Feb 3;27(3):1048. doi: 10.3390/molecules27031048.
The ditopic halogen-bond (X-bond) donors 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene (, , and , respectively) form binary cocrystals with the unsymmetrical ditopic X-bond acceptor -1-(2-pyridyl)-2-(4-pyridyl)ethylene (). The components of each cocrystal ()·(), ()·(), and ()·() assemble via N···I X-bonds. For ()·() and ()·(), the X-bond donor supports the C=C bonds of to undergo a topochemical [2+2] photodimerization in the solid state: UV-irradiation of each solid resulted in stereospecific, regiospecific, and quantitative photodimerization of to the corresponding head-to-tail () or head-to-head () cyclobutane photoproduct, respectively.
双齿卤素键（X 键）供体 1,2-、1,3-和 1,4-二碘代四氟苯（分别为、和）与不对称双齿 X 键受体-1-（2-吡啶基）-2-（4-吡啶基）乙烯（）形成二元共晶。每个共晶（）·（）、（）·（）和（）·（）（）通过 N···I X 键组装。对于（）·（）和（）·（），X 键供体支持的 C=C 键发生拓扑[2+2]光二聚化在固态中：对每个固体进行 UV 照射，导致相应的头对头（）或头对头（）环丁烷光产物的立体特异性、区域特异性和定量光二聚化。
