Smirnov Andrey S, Mikherdov Alexander S, Rozhkov Anton V, Gomila Rosa M, Frontera Antonio, Kukushkin Vadim Yu, Bokach Nadezhda A
Institute of Chemistry, Saint Petersburg State University, 7/9 Universitetskaya Nab., 199034, Saint Petersburg, Russian Federation.
Departament de Química, Universitat de les Illes Balears, Crta de Valldemossa km 7.5, 07122, Palma de Mallorca, Baleares, Spain.
Chem Asian J. 2023 Apr 3;18(7):e202300037. doi: 10.1002/asia.202300037. Epub 2023 Mar 3.
Co-crystallization of 180°-orienting σ-hole-accepting tectons, namely, 1,4-diisocyanobenzene (1) and 1,4-diisocyanotetramethylbenzene (2), with such homoditopic halogen bond donors as 1,4-diiodotetrafluorobenzene (1,4-FIB) and 4,4'-diiodoperfluorobiphenyl (4,4'-FIBP) afforded co-crystals 1 ⋅ 1,4-FIB, 1 ⋅ 4,4'-FIBP, and 2 ⋅ 1,4-FIB. Their solid-state structures exhibit 1D-supramolecular arrangements, which are based on poorly explored I⋅⋅⋅C halogen bonding; this study is the first in which the supramolecular assembly utilizing halogen bonding with a terminal C atom was performed. The use of the potentially tetrafunctional σ-hole accepting tetraiodoethylene (TIE) leads to supramolecular architecture of a higher dimension, 3D-framework, observed in the structure of 1 ⋅ TIE. DFT calculations, used to characterize the halogen bonding situation, revealed that the I⋅⋅⋅C non-covalent interactions are moderately strong, ranging from -4.07 in 1 ⋅ TIE to -5.45 kcal/mol in 2 ⋅ 1,4-FIB. The NBO analysis disclosed that LP(C)→σ* charge transfer effects are relevant in all co-crystals.
180°取向的σ-空穴接受体构造分子，即1,4-二异氰基苯（1）和1,4-二异氰基四甲基苯（2），与1,4-二碘四氟苯（1,4-FIB）和4,4'-二碘全氟联苯（4,4'-FIBP）等同二齿卤素键供体共结晶，得到共晶体1⋅1,4-FIB、1⋅4,4'-FIBP和2⋅1,4-FIB。它们的固态结构呈现出一维超分子排列，这种排列基于研究较少的I⋅⋅⋅C卤素键；本研究首次进行了利用与末端C原子的卤素键的超分子组装。使用潜在的四官能团σ-空穴接受体四碘乙烯（TIE）导致在1⋅TIE的结构中观察到更高维度的超分子结构，即三维框架。用于表征卤素键情况的密度泛函理论（DFT）计算表明，I⋅⋅⋅C非共价相互作用中等强度，范围从1⋅TIE中的-4.07到2⋅1,4-FIB中的-5.45 kcal/mol。自然键轨道（NBO）分析表明，LP(C)→σ*电荷转移效应在所有共晶体中都很重要。
