Magnetism of a complex [Fe(H2Bpz2)2(bipy-NH2)] (H2Bpz2 = dihydrobis(1-pyrazolyl)borate, bipy-NH2 = 4,4'-diamino-2,2'-bipyridine) has been altered from paramagnetic to spin-crossover (SCO) behavior, through protonation of one amino group of bipy-NH2 with CF3SO3H. Complete SCO transition, both in solid state and in solution, occurs at ambient temperature.

Three new pharmaceutical co-crystals: 1 PZA-MA (malonic acid), 2 PZA-SA (succinic acid, a new polymorph of a reported one), and 3 PZA-GA (glutaric acid) have been prepared and characterized by differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), and single-crystal X-ray diffraction. Wherein, PZA formed 1:1 co-crystals with MA and GA by acid–amide and acid–py heterosynthon, while it formed 2:1 co-crystal with SA by amide–amide homosynthon in addition to acid–amide and acid–py heterosynthon. Their melting points follow the order, PZA-GA < PZA-MA < PZA-SA, which are lower than the melting points of the individual components. Hirshfeld surface analysis revealed that N–H···O hydrogen bonding and π···π interactions for PZA in them follow the order: PZA-MA > PZA-SA > PZA-GA, while H–H and O–O interactions follow the order: PZA-MA < PZA-SA < PZA-GA. We also compared the Hirshfeld surfaces of the present co-crystals with the nine reported PZA co-crystals, which obtained important results. The studies of the solubility and dissolution showed a semiempirical inverse relationship with the melting point: the solubility follows the order, PZA-SA < PZA-GA < PZA-MA and dissolution rate follows the order, PZA-SA < PZA-MA < PZA-GA.

Owing to the critical roles it plays for both structure and functionality, hydrogen bonding has high hopes for the orientated applications in hydrogen-bonded organic frameworks (HOFs). Here in this work, a hydrogenbonding strategy is performed for adjusting the structure and functionality of a heme-like ligand meso-tetra(carboxy-phenyl)-porphyrin (TCPP) with co-former 1,3-di(4-pyridyl) propane (1,3-DPP). A 3D dynamic HOF TCPP-1,3-DPP, with permanent porosity is obtained. For this HOF, the two components form novel robust 1D porous stripes, with the 1,3-DPP molecules acting as the lining for the pores that are confined within the region between adjacent carboxyphenyl moieties of TCPP. This confinement has tuned the affinities of TCPP from hydrophobic into hydrophilic. Interestingly, the 1D stripes are further stacked by weak π…π interactions into a 3D framework, the latter is highly dynamic with 1D stripes sliding back and forth, upon pressurized and water adsorption in the solid-state under ambient conditions, respectively. The activated TCPP-1,3-DPP has a Brunauer-Emmett-Teller surface area of 258 m 2 g −1 , and shows a maximum adsorption capacity about 9.8% for water during the adsorption-desorption cycles, demonstrating a promising candidate for the real-world application in effective dehydration of industrial gases under ambient conditions.

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The currently involved two-dimensional materials (2DMs) are referred to as atomically thin-layered materials, which are composed of in-plane covalent or coordinated crystalline sheets with different chemical compositions and crystal structures. However, if the crystalline sheets supported by in-plane noncovalent intermolecular interactions, such as hydrogen-bonding, van der Waals, etc., can be exfoliated into stable atomically thin nanosheets, then the category and members of the 2DM family will be expanded significantly and extensively. Here we demonstrate that, through an ultrasonic force-assisted top-down fabrication technology in the aqueous solution, the three-dimensional hydrogen-bonded organic framework (HOF) TCPP-1,3-DPP, which is composed of onedimensional (1D) porous ribbons that are held together via robust hydrogenbonding contacts, can be exfoliated into atomically thin 1D porous nanoribbons (nr-HOF), providing a fine-dispersed stable colloidal suspension with a significant Tyndall effect and ultrahigh surface sensitivity. In addition, the fully exposed surface and strong surface adsorption ability of nr-HOF account for the high loading capacity of doxorubicin (Doxo; 29.4%, nr-HOF@Doxo), providing a smart carrier for an anticancer drug featuring the desired synergistic chemotherapy−photodynamic therapy−photothermal therapy effects that is more effective than the commercial Doxo drug, with a cell viability as low as 1.3%. All of these results have demonstrated brand-new 2DMs with appealing properties and applications.