Summary Single-crystal X-ray diffraction analysis (SCXRD) constitutes a universal approach for the elucidation of molecular structure and the study of crystalline forms. However, the discovery of viable crystallization conditions remains both experimentally challenging and resource intensive in both time and the quantity of analyte(s). We report a robot-assisted, high-throughput method for the crystallization of organic-soluble small molecules in which we employ only micrograms of analyte per experiment. This allows hundreds of crystallization conditions to be screened in parallel with minimal overall sample requirements. Crystals suitable for SCXRD are grown from nanoliter droplets of a solution of analyte in organic solvent(s), each of which is encapsulated within an inert oil to control the rate of solvent loss. This encapsulated nanodroplet crystallization methodology can also be used to search for new crystal forms, as exemplified through both our discovery of a new (13 th ) polymorph of the olanzapine precursor ROY and SCXRD analysis of the “uncrystallizable” agrochemical dithianon.

The synthesis of conventional porous crystals involves building a framework using reversible chemical bond formation, which can result in hydrolytic instability. In contrast, porous molecular crystals assemble using only weak intermolecular interactions , which generally do not provide the same environmental stability. Here, we report that the simple co-crystallization of a phthalocyanine derivative and a fullerene (C60 or C70) forms porous molecular crystals with environmental stability towards high temperature and hot aqueous base or acid. Moreover, by using diamond anvil cells and synchrotron single-crystal measurements, stability towards extreme pressure (>4 GPa) is demonstrated, with the stabilizing fullerene held between two phthalocyanines and the hold tightening at high pressure. Access to open metal centres within the porous molecular co-crystal is demonstrated by in situ crystallographic analysis of the chemisorption of pyridine, oxygen and carbon monoxide. This suggests strategies for the formation of highly stable and potentially functional porous materials using only weak van der Waals intermolecular interactions. tability is one of the key properties of a porous material and diameter. In addition, there are relatively narrow cavities, ~1.2 nm determines its suitability for application1. The construction of in diameter, that lie between the hexa-phthalocyanine assemblies. Semergent porous organic materials, such as metal-organic Remarkably, the same phthalocyanine nanoporous crystal (PNC) 2 3 structure reoccurs for many metal complexes of (dipPhO)8PcM frameworks (MOFs) and covalent organic frameworks (COFs) , relies on the reversible formation of a network of chemical bonds (for example M = Mg, Al, Ti, Mn, Fe, Co, Zn, Ru, In)20. In addibetween molecular components. Reversible bond formation is tion, the PNC structure is compatible with a large variation in size, required to allow the correction of defects to provide an ordered shape, type and number of ligands, which may be placed at either structure, but this also limits the chemical stability of the materials, of the two distinct axial sites of the metal that face into the void (v) particularly towards strongly hydrolytic environments. An alterna-or cavity (c)20,21. As is commonly encountered in molecular crystive and very direct approach to a crystalline porous material, as it tals containing very large solvent-filled voids, structural collapse does not involve bond formation, is the crystallization of a molecu-occurs rapidly on removal of the solvate crystal from contact with lar component to form a solvated crystal, from which the included the solvent of recrystallization. Previously, it was established that solvent is then removed to generate porosity. For most molecular suitable bidentate ligands, such as 4,4′-bipyridyl (bipy), can act as crystals, the removal of included solvent results in structural col-molecular wall-ties by binding together two metal cations across the lapse due to the lack of a stabilizing framework of bonds. However, cav...

A new MnIII complex exhibits a gradual spin crossover phenomenon with single crystal thermochromism. A comparative structural study was conducted using octahedral deviation parameters.

In-situ single-crystal diffraction and spectroscopic techniques have been used to study a previously unreported Cu-framework bis[1-(4-pyridyl)butane-1,3-dione]copper(II) (CuPyr-I). CuPyr-I was found to exhibit high-pressure and low-temperature phase transitions, piezochromism, negative linear...