Crystal structure, thermal behaviour and phase transitions of formamidinium iodide were studied by DTG, DSC, powder diffraction and X-ray crystallography.

Introduction of "Belok/XSA" beamline-modernization is presented here with commissioning of a modern synchrotron beamline with unique capabilities for the structural analysis of single and polycrystalline samples. The beamline is designed to perform important tasks in modern crystallography, such as solving and refining the atomic structure using the single-and polycrystal method, studying the real (defective) structure, and analyzing the distribution of electron density in crystals, it is also possible to study rapidly occurring processes, for example, temperature phase transitions. Due to the speed of data accumulation and a registration over a large solid angle, the method allows to study large numbers of samples. This beamline has become extremely demanded in the chemical, biological, material science, and archaeological community in Russia.

Green fluorescent genetically encoded calcium indicators (GECIs) are the most popular tool for visualization of calcium dynamics in vivo. However, most of them are based on the EGFP protein and have similar molecular brightnesses. The NTnC indicator, which is composed of the mNeonGreen fluorescent protein with the insertion of troponin C, has higher brightness as compared to EGFP-based GECIs, but shows a limited inverted response with an ΔF/F of 1. By insertion of a calmodulin/M13-peptide pair into the mNeonGreen protein, we developed a green GECI called NCaMP7. In vitro, NCaMP7 showed positive response with an ΔF/F of 27 and high affinity (Kd of 125 nM) to calcium ions. NCaMP7 demonstrated a 1.7-fold higher brightness and similar calcium-association/dissociation dynamics compared to the standard GCaMP6s GECI in vitro. According to fluorescence recovery after photobleaching (FRAP) experiments, the NCaMP7 design partially prevented interactions of NCaMP7 with the intracellular environment. The NCaMP7 crystal structure was obtained at 1.75 Å resolution to uncover the molecular basis of its calcium ions sensitivity. The NCaMP7 indicator retained a high and fast response when expressed in cultured HeLa and neuronal cells. Finally, we successfully utilized the NCaMP7 indicator for in vivo visualization of grating-evoked and place-dependent neuronal activity in the visual cortex and the hippocampus of mice using a two-photon microscope and an NVista miniscope, respectively.

A series of new zinc­(II)–thiophene-2,5-dicarboxylate (tdc) MOFs based on novel dodecanuclear wheel-shaped building blocks has been synthesized in almost quantative yields. Single-crystal X-ray diffraction analyses reveal 3D porous frameworks with a complex composition [Zn12(tdc)6(glycolate)6(dabco)3] where glycolate is a deprotonated polyatomic alcohol (ethylene glycol, EgO2, 1; 1,2-propanediol, PrO2, 2; 1,2-butanediol, BuO2, 3; 1,2-pentanediol, PeO2, 4; glycerol, GlO2, 5) and dabco is 1,4-diazo[2.2.2.]­bicyclooctane. All compounds 1–5 are isostructural except for pendant groups of the diols decorating the surface of channels. The adsorption of small gases (N2, CO2, CH4, C2H2, C2H4, C2H6) and larger hydrocarbons (benzene, cyclohexane) both in liquid and vapor phases was thoroughly investigated for all compounds. The zero-coverage adsorption enthalpies, Henry constants, and selectivity factors by various models are calculated and discussed. The versatile adsorption functionality of the title series results from the variable nature of the diol and could be tailored for a specific adsorbate system. For example, 1 shows excellent selectivity of benzene over cyclohexane (20:1 for vapors, 92:1 for liquid phase), while 4 demonstrates unprecedented adsorption preference of cyclohexane over benzene (selectivity up to 5:1). The compound 5 demonstrates great adsorption selectivity for CO2/N2 (up to 75.1), CO2/CH4 (up to 7.7), C2H2/CH4 (up to 14.2), and C2H4/CH4 (up to 9.4). Also, due to polar nature of the pores, 5 features size-selective sorption of alkaline metal cations in order Li+ > Na+ > K+ > Cs+ as well as a notable luminescent response for cesium­(I) ions and urea.

This paper concisely describes capabilities of the 'Belok' beamline at the Kurchatov synchrotron radiation source, related to high-throughput small-molecule X-ray crystallography.As case examples, a series of four novel transition metal complexes with azomethine ligands were selected. The complexes demonstrate somewhat unexpected changes in the coordination geometry and nuclearity in response to the introduction of substituents in the ligand's periphery.