Carbon Nitrides from Supramolecular Crystals: From Single Atoms to Heterojunctions and Advanced Photoelectrodes

Carbon nitride materials (CN) have become one of the most studied photocatalysts within the last 15 years. While CN absorbs visible light, its low porosity and fast electron-hole recombination hinder its photoelectric performance and have motivated the research in the modification of its physical and chemical properties (such as energy band structure, porosity, or chemical composition) by different means. In this Concept we review the utilization of supramolecular crystals as CN precursors to tailor its properties. We elaborate on the features needed in a supramolecular crystal to serve as CN precursor, we delve on the influence of metal-free crystals in the morphology and porosity of the resulting materials and then discuss the formation of single atoms and heterojunctions when employing a metal-organic crystal. We finally discuss the performance of CN photoanodes derived from crystals and highlight the current standing challenges in the field.

2,4-Diamino-6-phenyl-1,3,5-triazin-1-ium nitrate: intriguing crystal structure with high Z′/Z′′ and hydrogen bond numbers and Hirshfeld surface analysis of intermolecular interactions

The title compound crystallises in the triclinic centrosymmetric space group P1̄ with an intriguing high number of crystallographically unique binary salt-like adducts (Z′ = 8) and a total number of ionic species (Z′′ = 16) in the asymmetric unit.

Preparation, characterization and molecular modeling studies of the beta-cyclodextrin inclusion complex with benzoguanamine and its analytical application as chemosensor for the selective sensing of Ce4

The inclusion complex of β-cyclodextrin (β-CD) with benzoguanamine (BGA) has been investigated in three states. UV-Visible and fluorescence spectral techniques are used in liquid state. FTIR, NMR and MASS techniques are used in solid state and virtual state studies are done by molecular simulation work. The binding constants for the formation of 1:1 BGA:β-CD inclusion complex is estimated by UV-Visible and fluorescence spectral techniques. The chemosensory ability of BGA:β-CD complex was investigated thoroughly for various metal cations and we found the emission of complex showed a linear increase in the intensity for Ce⁴⁺ with the linearity range of 1000 μM-2000 μM. Sensitivity analysis shows good sensing for Ce⁴⁺ with the LOD of 671 μM and LOQ of 2034 μM. Our result suggests that the BGA:β-CD inclusion complex would be promising material for developing solid state sensory device for sensing Ce⁴⁺.

A one-dimensional silver(I) coordination polymer based on an asymmetric flexible N-donor carboxylate ligand: catena-poly[(μ3-4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoato-κ(3)O:O':N(4))silver(I)]

The title compound, [Ag(C15H11N4O2S)]n, was synthesized by the reaction of 4-{[(1-phenyl-1H-tetrazol-5-yl)sulfanyl]methyl}benzoic acid (Hptmba) with silver nitrate and triethylamine at room temperature. The asymmetric unit contains one crystallographically independent Ag(I) cation and one ptmba(-) ligand. Each Ag(I) cation is tricoordinated by two carboxylate O atoms and one tetrazole N atom from three different ptmba(-) ligands, displaying a distorted T-shaped geometry. Three Ag(I) cations are linked by tris-monodentate bridging ptmba(-) ligands to form a one-dimensional double chain along the c axis, which is further consolidated by an intrachain π-π contact with an offset face-to-face distance of 4.176 (3) Å between the centroids of two adjacent aromatic rings in neighbouring benzoate groups. The one-dimensional chains are linked into a three-dimensional supramolecular framework by additional π-π interchain interactions, viz. of 3.753 (3) Å between two phenyl substituents of the tetrazole rings and of 4.326 (2) Å between a benzoate ring and a tetrazole ring. Thermogravimetric analysis and the fluorescence spectrum of the title compound reveal its good thermal stability and a strong green luminescence at room temperature.

Five metal–organic frameworks from 3,4-dimethylphenyl substituted imidazole dicarboxylate: syntheses, structures and properties

Five metal–organic frameworks have been hydrothermally synthesized and structurally characterized.