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.

A Million Crystal Structures: The Whole Is Greater than the Sum of Its Parts

The founding in 1965 of what is now called the Cambridge Structural Database (CSD) has reaped dividends in numerous and diverse areas of chemical research. Each of the million or so crystal structures in the database was solved for its own particular reason, but collected together, the structures can be reused to address a multitude of new problems. In this Review, which is focused mainly on the last 10 years, we chronicle the contribution of the CSD to research into molecular geometries, molecular interactions, and molecular assemblies and demonstrate its value in the design of biologically active molecules and the solid forms in which they are delivered. Its potential in other commercially relevant areas is described, including gas storage and delivery, thin films, and (opto)electronics. The CSD also aids the solution of new crystal structures. Because no scientific instrument is without shortcomings, the limitations of CSD research are assessed. We emphasize the importance of maintaining database quality: notwithstanding the arrival of big data and machine learning, it remains perilous to ignore the principle of garbage in, garbage out. Finally, we explain why the CSD must evolve with the world around it to ensure it remains fit for purpose in the years ahead.

Crystal structure and Hirshfeld surface analysis of 2,4-di-amino-6-phenyl-1,3,5-triazin-1-ium 4-methyl-benzene-sulfonate

The asymmetric unit consists of a 2,4-di­amino-6-phenyl-1,3,5-triazin-1-ium cation and a 4-methyl­benzoate anion. The protonated nitro­gen and amino group nitro­gen atoms are involved in hydrogen bonding with the sulfonate oxygen atoms through a pair of inter­molecular N—H⋯O hydrogen bonds. The inversion-related mol­ecules are further linked by four N—H⋯O inter­molecular inter­ations to produce a complementary DDAA hydrogen-bonded array. Hirshfeld surface analysis was employed to further examine the inter­molecular inter­actions.

In the title mol­ecular salt, C₉H₁₀N₅⁺·C₇H₇O₃S⁻, the asymmetric unit consists of a 2,4-di­amino-6-phenyl-1,3,5-triazin-1-ium cation and a 4-methyl­benzene­sulfonate anion. The cation is protonated at the N atom lying between the amine and phenyl substituents. The protonated N and amino-group N atoms are involved in hydrogen bonding with the sulfonate O atoms through a pair of inter­molecular N—H⋯O hydrogen bonds, giving rise to a hydrogen-bonded cyclic motif with R₂²(8) graph-set notation. The inversion-related mol­ecules are further linked by four N—H⋯O inter­molecular inter­actions to produce a complementary DDAA (D = donor, A = acceptor) hydrogen-bonded array, forming R₂²(8), R₄²(8) and R₂²(8) ring motifs. The centrosymmetrically paired cations form R₂²(8) ring motifs through base-pairing via N—H⋯N hydrogen bonds. In addition, another R₃³(10) motif is formed between centrosymetrically paired cations and a sulfonate anion via N—H⋯O hydrogen bonds. The crystal structure also features weak S=O⋯π and π–π inter­actions. Hirshfeld surface and fingerprint plots were employed in order to further study the inter­molecular inter­actions.

Structural studies of crystalline forms of triamterene with carboxylic acid, GRAS and API molecules

Pharmaceutical salt solvates (dimethyl sulfoxide, DMSO) of the drug triamterene with the coformers acetic, succinic, adipic, pimelic, azelaic and nicotinic acid and ibuprofen are prepared by liquid-assisted grinding and solvent-evaporative crystallization. The modified ΔpKa rule as proposed by Cruz-Cabeza [(2012 ▸). CrystEngComm, 14, 6362-6365] is in close agreement with the results of this study. All adducts were characterized by X-ray diffraction and thermal analytical techniques, including single-crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry and thermal gravimetric analysis. Hydrogen-bonded motifs combined to form a variety of extended tapes and sheets. Analysis of the crystal structures showed that all adducts existed as salt solvates and contained the amino-pyridinium-carboxyl-ate heterodimer, except for the solvate containing triamterene, ibuprofen and DMSO, as a result of the presence of a strong and stable hemitriamterenium duplex. A search of the Cambridge Structural Database (CSD 5.36, Version 1.18) to determine the frequency of occurrence of the putative supramolecular synthons found in this study showed good agreement with previous work.

An exploration into the amide–pseudo amide hydrogen bonding synthon between a new coformer with two primary amide groups and theophylline

Double the FUN! A rare amide–pseudo amide hydrogen bonding synthon has been established for the co-crystal between a new coformer with two primary amide groups and theophylline.