The synthesis, crystal structure and Hirshfeld surface analysis of the thio­phene derivatives 5-(phenyl­sulfon­yl)-5,6-di­hydro­benzo[4,5]thieno[3,2-j]phenanthridine and (E)-N-{2-[2-(benzo[b]thiophen-2-yl)ethenyl]phen­yl}-N-(prop-2-yn-1-yl)benzene­sulfonamide

The crystal structures of two benzo­thio­phene derivatives are described along with an analysis of the inter­molecular contacts in the crystals performed using Hirshfeld surface analysis and two-dimensional fingerprint plots.

Crystal structure and Hirshfeld surface analysis of 2-amino-6-[(1-phenyl­eth­yl)amino]-4-(thio­phen-2-yl)pyridine-3,5-dicarbo­nitrile

In the crystal, the mol­ecules are connected by N—H⋯N hydrogen bonds into dimers with an (12) motif, forming chains along the b-axis direction. These chains are linked to each other by N—H⋯N hydrogen bonds, N–H⋯π and π–π inter­actions, forming a three-dimensional network.

Crystal structure of 4-[(4-methyl­benz­yl)­oxy]-N′-(4-nitro­benzyl­idene)benzohydrazide: a new hydrazone derivative

The title aroylhydrazone ether exists in an E-configuration with respect to the double bond of the hydrazone bridge and with an ac­yl–hydrazone (—CH=N—NH—CO—) torsion angle of 166.0 (3)°. The mol­ecule exhibits a non-planar conformation, likely induced by packing requirements.

Polymorphic structures of 3-phenyl-1H-1,3-benzo­diazol-2(3H)-one

The two polymorphic structures of 3-phenyl-1H-1,3-benzo­diazol-2(3H)-one (I and II) exhibit identical bond distances and angles except for the C—N—C—C torsion angle between the benzimidazolone backbone and the phenyl substituent, which has an effect on the crystal packing and supra­molecular features. The structure of I contains a stronger C=O⋯H—N hydrogen-bonding inter­action and a weaker π–π inter­action between adjacent bezimidazolone moieties in comparison to II.

Syntheses, crystal structures, Hirshfeld surface analyses and energy frameworks of two 4-amino­anti­pyrine Schiff base compounds: (E)-4-{[4-(di­ethyl­amino)­benzyl­idene]amino}-1,5-di­methyl-2-phenyl-1H-pyrazol-3(2H)-one and (E)-4-[(4-fluoro­benzyl­idene)amino]-1,5-di­methyl-2-phenyl-1H-pyrazol-3(2H)-one

The title 4-amino­anti­pyrine Schiff base compounds both deviate from planarity with the phenyl ring and the substituted benzyl­idene ring being inclined to the pyrazole ring mean plane by 54.87 (7) and 22.92 (7)°, respectively, in the first compound and by 60.44 (8) and 12.70 (9)° in the second.

Synthesis, crystal structure and Hirshfeld surface analysis of (E)-benzo[d][1,3]dioxole-5-carbaldehyde oxime

The asymmetric unit of the title compound consists of two independent mol­ecules differing slightly in conformation and in their inter­molecular inter­actions in the solid.

Synthesis and structure of photodegradable 1-(4,5-dimeth­oxy-2,3-di­nitro­phen­yl)-2-methyl­propyl N-butyl­carbamate

1-(4,5-Dimeth­oxy-2,3-di­nitro­phen­yl)-2-methyl­propyl butyl­carbamate, which affords butyl­amine on photoirradiation, was prepared by the reaction of 1-(4,5-dimeth­oxy-2,3-di­nitro­phen­yl)-2-methyl­propan-1-ol and butyl­iso­cyanate using di­butyl­tin dilaurate as a catalyst. Single crystals of the carbamate were grown in a 1:1 mixed solution of hexane and ethyl acetate. Two nitro groups and one meth­oxy group of the novel photo-protecting group were twisted out of the plane of the aromatic ring and inter­molecular hydrogen bonds are observed between carbamate moieties.

Syntheses, crystal structures and Hirshfeld surface analysis of 2-(benzyl­sulfan­yl)-5-[4-(di­methyl­amino)­phen­yl]-1,3,4-oxa­diazole and 2-[(2-chloro-6-fluoro­benz­yl)sulfan­yl]-5-[4-(di­methyl­amino)­phen­yl]-1,3,4-oxa­diazole

The title mol­ecules were synthesized by alkyl­ation of 5-[(4-di­methyl­amino)­phen­yl]-1,3,4-oxa­diazole-2-thiol. In the crystals, C–H⋯π inter­actions are observed between neighboring mol­ecules. Hirshfeld surface analysis indicates that H⋯H and H⋯C/C⋯H inter­actions make the most important contributions to the crystal packing.

Synthesis and crystal structure studies of 5-(tri­fluoro­meth­yl)-1,3,4-thia­diazol-2(3H)-one at 180 K

The synthesis and crystal structure of 5-(tri­fluoro­meth­yl)-1,3,4-thia­diazol-2(3H)-one, a heterocycle of importance as a pharmaceutical building block, are presented.

2-[3-(1H-Benzimidazol-2-yl)prop­yl]-1H-benzimidazol-3-ium 3,4,5-tri­hydroxy­benzoate–1,3-bis­(1H-benzimidazol-2-yl)propane–ethyl acetate (2/1/2.94): co-crystallization between a salt, a neutral mol­ecule and a solvent

The title compound can be described as a salt (HL)⁺(Gal)⁻ (L = 1,3-bis­(benzimidazol-2-yl)propane (L); HGal = gallic acid) co-crystallized with a neutral mol­ecule L. The crystal also comprises disordered solvent ethyl acetate mol­ecules.

Crystal structure and Hirshfeld surface analysis of 5-oxo-7-phenyl-2-(phenyl­amino)-1H-[1,2,4]triazolo[1,5-a]pyridine-6,8-dicarbo­nitrile di­methyl sulfoxide monosolvate

In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds connect mol­ecules into chains along the b-axis direction through the dimethyl sulfoxide solvent mol­ecule, forming C(10)(6) motifs. These chains are connected via S—O⋯π inter­actions, π–π stacking inter­actions and van der Waals inter­actions.

Synthesis and crystal structure of 2-[(2,3,5,6-tetra­fluoro­pyridin-4-yl)amino]­ethyl methacrylate

In the crystal structure of the title compound, the packing is driven by C—H⋯F, N—H⋯O and C—H⋯π contacts. Hirshfeld surface analysis showed that the largest contribution to the surface contacts arise from F⋯H/H⋯F inter­actions.

Synthesis and crystal structure of bis­(2-phthal­imido­eth­yl)ammonium chloride dihydrate

The title compound is a phthalimide-protected polyamine with a protonated central nitro­gen atom. The crystal packing features a hydrogen-bond network, a two-coordinated chloride ion, and off-set π–π stacking.

David G. Watson (1934–2023)

Obituary for David Watson.