Structural adaptation in a cadmium-porphyrin MOF through solvent-driven change of interpenetration

Cadmium–porphyrin metal–organic frameworks combine the structural rigidity of the porphyrin core with the coordination flexibility of closed-shell Cd²⁺ centres, enabling diverse framework topologies and versatile applications. In the publication associated to this dataset, we report a single-crystal-to-single-crystal transformation in a CdCl₂–meso-tetra(4-pyridyl)porphyrin (H2TPyP) MOF induced by mild thermal desolvation (120°C in air). The solvated MOF (UB-MOF-1) adopts a non-interpenetrated CdSO₄-type topology stabilized by 1,1,2,2-tetrachloroethane and 3-chloroaniline guests. Upon solvent removal, the framework undergoes irreversible drastic rearrangement to a two-fold interpenetrated cds-type network (ESRF-1), accompanied by more than a twofold reduction in accessible pore volume. The periodic DFT calculations of the two MOFs done with CP2K and deposited here, show that, while guest inclusion substantially stabilizes the open framework UB-MOF-1, the interpenetrated, solvent-free ESRF-1 is thermodynamically favoured over the hypothetical empty UB-MOF-1 as interpenetration provides even greater stabilization. The transformation, driven by framework densification, is irreversible due to geometric pore constraints. This study demonstrates how controlled solvent manipulation can trigger topology changes in porphyrin-based MOFs, offering a route to design dense, structurally locked architectures with tailored accessibility.

镉-卟啉金属有机框架（cadmium–porphyrin metal–organic frameworks）将卟啉（porphyrin）核心的结构刚性与闭壳层Cd²⁺中心的配位灵活性相结合，可构筑多样的框架拓扑结构并实现多功能应用。本数据集关联的研究论文报道了一种由温和热脱溶剂（空气中120℃）诱导的氯化镉-间位-四(4-吡啶基)卟啉(H2TPyP)金属有机框架（metal–organic framework, MOF）的单晶到单晶转变。该溶剂化MOF（UB-MOF-1）采用非互穿CdSO₄型拓扑结构，由1,1,2,2-四氯乙烷和3-氯苯胺客体分子稳定。脱除溶剂后，该框架发生不可逆的剧烈重排，形成二重互穿的cds型网络（ESRF-1），可及孔体积缩减超过两倍。本文采用CP2K软件完成的两种MOFs的周期性密度泛函理论（periodic density functional theory, DFT）计算结果已随本数据集存档，结果表明：尽管客体包合可显著稳定开放框架UB-MOF-1，但相较于假想的空态UB-MOF-1，无溶剂的互穿型ESRF-1热力学更稳定，这是因为互穿结构可提供更强的稳定作用。该转变由框架致密化驱动，受几何孔道约束影响而不可逆。本研究证实，可控溶剂调控可触发卟啉基MOFs的拓扑结构转变，为构建致密化、结构锁定且具备定制化孔道可及性的框架材料提供了可行路径。