Zhu Qiang, Johal Jay, Widdowson Daniel E, Pang Zhongfu, Li Boyu, Kane Christopher M, Kurlin Vitaliy, Day Graeme M, Little Marc A, Cooper Andrew I
Materials Innovation Factory and Department of Chemistry, University of Liverpool, Liverpool L7 3NY, U.K.
Leverhulme Research Centre for Functional Materials Design, University of Liverpool, Liverpool L7 3NY, U.K.
J Am Chem Soc. 2022 Jun 8;144(22):9893-9901. doi: 10.1021/jacs.2c02653. Epub 2022 May 29.
Mesoporous molecular crystals have potential applications in separation and catalysis, but they are rare and hard to design because many weak interactions compete during crystallization, and most molecules have an energetic preference for close packing. Here, we combine crystal structure prediction (CSP) with structural invariants to continuously qualify the similarity between predicted crystal structures for related molecules. This allows isomorphous substitution strategies, which can be unreliable for molecular crystals, to be augmented by prediction, thus leveraging the power of both approaches. We used this combined approach to discover a rare example of a low-density (0.54 g cm) mesoporous hydrogen-bonded framework (HOF), . This structure comprises an organic cage () that was predicted to form kinetically trapped, low-density polymorphs CSP. Pointwise distance distribution structural invariants revealed five predicted forms of that are analogous to experimentally realized porous crystals of a chemically different but geometrically similar molecule, . More broadly, this approach overcomes the difficulties in comparing predicted molecular crystals with varying lattice parameters, thus allowing for the systematic comparison of energy-structure landscapes for chemically dissimilar molecules.
介孔分子晶体在分离和催化领域具有潜在应用，但它们很罕见且难以设计，因为在结晶过程中有许多弱相互作用相互竞争，并且大多数分子在能量上倾向于紧密堆积。在此，我们将晶体结构预测（CSP）与结构不变量相结合，以持续量化相关分子预测晶体结构之间的相似性。这使得对于分子晶体可能不可靠的同构替代策略能够通过预测得到增强，从而利用两种方法的优势。我们使用这种组合方法发现了一个低密度（0.54 g/cm）介孔氢键框架（HOF）的罕见实例。这种结构包含一个有机笼（），经预测它会形成动力学捕获的低密度多晶型物 CSP。逐点距离分布结构不变量揭示了的五种预测形式，它们类似于化学性质不同但几何结构相似的分子的实验实现的多孔晶体。更广泛地说，这种方法克服了比较具有不同晶格参数的预测分子晶体的困难，从而允许对化学性质不同的分子的能量 - 结构景观进行系统比较。
