Impact of Torsional and Conformational Flexibility on Pedal Motion and Thermal Expansion in Pyridyl Bisimine Cocrystals
Impact of Torsional and Conformational Flexibility on Pedal Motion and Thermal Expansion in Pyridyl Bisimine Cocrystals
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DOI：
10.1021/acs.cgd.2c01158
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发表时间：
2022-12-21
影响因子：
3.8
通讯作者：
Hutchins，Kristin M.
中科院分区：
文献类型：
--
作者：
Juneja，Navkiran;Unruh，Daniel K.;Hutchins，Kristin M.
分子间相互作用和分子运动对固体性质的影响是化学家和材料科学家感兴趣的活跃领域。例如，当与单组分固体相比时，共结晶已经显示出改变和/或增强分子的固态行为。在这里，我们描述了一系列的共晶含有双（吡啶-4-基亚甲基）苯-1，4-二胺（BPDI）和ditopic或tritopic氢键供体分子，构象灵活。所有共晶中的组分通过羟基-吡啶杂环自组装得到一维链，由于供体分子的构象，BPDI是扭转柔性的，并且在与双位氢键供体的共晶中，分子几乎是平面的，而在与三位氢键供体的共晶中，BPDI是显著扭曲的。BPDI中的这种扭曲影响晶体堆积并提供更高的热膨胀系数。BPDI与另一种扭转柔性分子白藜芦醇的共结晶诱导了BPDI中的分子踏板运动，并导致共晶体中更大的膨胀行为。
The impact of intermolecular interactions and molecular motion on solid-state properties is an active field of interest for chemists and materials scientists. For example, cocrystallization has been shown to modify and/or enhance the solid-state behaviors of a molecule when compared to the single-component solid. Here, we describe a series of cocrystals containing bis(pyridin-4-ylmethylene)benzene-1,4-diamine (BPDI) and ditopic or tritopic hydrogen-bond-donor molecules that are conformationally flexible. The components in all the cocrystals self-assemble through hydroxyl-pyridine heterosynthons to afford one-dimensional chains due to the conformations of the donor molecules.BPDIis torsionally flexible, and in cocrystals with ditopic hydrogen-bond donors, the molecule is almost planar, whereas in cocrystals with tritopic hydrogen-bond donors,BPDIis significantly twisted. This twisting inBPDIaffects crystal packing and affords higher thermal expansion coefficients. Cocrystallization ofBPDIwith resveratrol, another torsionally flexible molecule, induces molecular pedal motion inBPDIand results in larger expansion behavior in the cocrystal.