Syntheses and crystal structures of 2-(p-tolyl)-1H-perimidine hemihydrate and 1-methyl-2-(p-tolyl)-1H-perimidine

The title compounds, 2-(4-methylphenyl)-1H-perimidine hemihydrate (1, C18H14N2·0.5H2O) and 1-methyl-2-(4-methylphenyl)-1H-perimidine (2, C19H16N2), were prepared and characterized by 1H NMR and single-crystal X-ray diffraction. The organic molecule of the hemihydrate lies on a twofold rotation axis while the water molecule lies on the intersection of three twofold rotation axes (point group symmetry 222). As a consequence, the hydrogen atoms that are part of the N—H group and the water molecule as well as the CH3 group of the p-tolyl ring are disordered over two positions. In compound 1, the perimidine and the 2-aryl rings are slightly twisted while its N-methylated derivative 2 has a more distorted conformation because of the steric repulsion between the N-methyl group and the 2-aryl ring. In the crystal structures, molecules of perimidine 2 are held together only by C—H...π contacts while the parent perimidine 1 does not exhibit this type of interaction. Its crystal packing is established by intermolecular N—H...O hydrogen bonds with the solvent water molecules and additionally stabilized by π–π stacking.

Crystal structure, DFT and Hirshfeld surface analysis of N-acetyl-t-3-methyl-r-2,c-6-diphenylpiperidine

In the title compound [systematic name: 1-(3-methyl-2,6-diphenylpiperidin-1-yl)ethanone], C20H23NO, the piperidine ring adopts a distorted boat conformation, while the phenyl rings subtend a dihedral angle 65.1 (2)°. In the crystal, molecules are linked by C—H...O hydrogen bonds into chains extending along the b-axis direction. The DFT/B3LYP/6–311 G(d,p) method was used to determine the HOMO–LUMO energy levels. A Hirshfeld surface analysis was conducted to verify the contributions of the different intermolecular interactions, indicating that the important contributions to the crystal packing are from H...H (73.2%), C...H (18.4%) and O...H (8.4%) interactions.

Crystal structures of three N,N,N′-trisubstituted thioureas for reactivity-controlled nanocrystal synthesis

The synthesis and single-crystal X-ray structures of three N,N,N′-trisubstituted thioureas are reported, namely N,N,N′-tribenzylthiourea, C22H22N2S (1), N-methyl-N,N′-diphenylthiourea, C14H14N2S (2), and N,N-di-n-butyl-N′-phenylthiourea, C15H24N2S (3). The influence of the different substituents on the thioureas is clear from the delocalization of the thiourea C—N and C=S bonds, while the crystal structures show infinite chains of N,N,N′-tribenzylthiourea (1), hydrogen-bonded pairs of N-methyl-N,N′-diphenylthiourea (2) and hexamer ring assemblies of N,N-di-n-butyl-N′-phenylthiourea (3) molecules. The above-mentioned compounds were synthesized via a mild, general procedure, readily accessible precursors and with a high yield, providing straightforward access to a whole library of thioureas.

An orthorhombic polymorph of 2-(1,3,5-dithiazinan-5-yl)ethanol or MEA-dithiazine

Substituted triazines are a class of compounds utilized for scavenging and sequestering hydrogen sulfide in oil and gas production operations. The reaction of one of these triazines under field conditions resulted in the formation of the title compound, 2-(1,3,5-dithiazinan-5-yl)ethanol, C5H11NOS2, or MEA-dithiazine. Polymorphic form I, in space group I41/a, was first reported in 2004 and its extended structure displays one-dimensional, helical strands connected through O—H...O hydrogen bonds. We describe here the form II polymorph of the title compound, which crystallizes in the orthorhombic space group Pbca as centrosymmetric dimers through pairwise O—H...N hydrogen bonds from the hydroxyl moiety to the nitrogen atom of an adjacent molecule.

Crystal structure and Hirshfeld surface analysis of the hydrated 2:1 adduct of piperazine-1,4-diium 3,5-dinitro-2-oxidobenzoate and piperazine

The crystal structure of the adduct piperazine-1,4-diium 3,5-dinitro-2-oxidobenzoate–piperazine–water (2/1/2) shows the existence of a 3,5-dinitrosalicylate dianion (DNSA2−) and a protonated piperazine-1,4-diium cation (PIP2+) along with a piperazine molecule. The formula of the title adduct in the asymmetric unit is 2C4H12N2 2+·2C7H2N2O7 2−·C4H10N2·2H2O with Z = 1. The piperazine ring in the piperazine-1,4-diium cation and in the neutral piperazine molecule adopt chair conformations. All O atoms in the DNSA2− moiety and the water molecule act as hydrogen-bonding acceptors for various intermolecular O—H...O, N—H...O and C—H...O interactions, which stabilize the crystal structure. Various supramolecular architectures formed by the different intermolecular interactions are discussed. The relative contribution of various intermolecular contacts is analysed with the aid of two-dimensional (full and decomposed) fingerprint plots, indicating that H...O/O...H (50.2%) and H...H (36.2%) contacts are the major contributors to the stabilization of the crystal structure.

NiII molecular complex with a tetradentate aminoguanidine-derived Schiff base ligand: structural, spectroscopic and electrochemical studies and photoelectric response

The new molecular nickel(II) complex, namely, {4-bromo-2-[({N′-[(2-oxidobenzylidene)amino]carbamimidoyl}imino)methyl]phenolato}nickel(II) N,N-dimethylformamide solvate monohydrate, [Ni(C15H11BrN4O2)]·C3H7NO·H2O, (I), crystallizes in the triclinic space group P\overline{1} with one molecule per asymmetric unit. The guanidine ligand is a product of Schiff base condensation between aminoguanidine, salicylaldehyde and 5-bromosalicylaldehyde templated by Ni2+ ions. The chelating ligand molecule is deprotonated at the phenol O atoms and coordinates the metal centre through the two azomethine N and two phenolate O atoms in a cis-NiN2O2 square-planar configuration [average(Ni—N/O) = 1.8489 Å, cis angles in the range 83.08 (5)–95.35 (5)°, trans angles of 177.80 (5) and 178.29 (5)°]. The complex molecule adopts an almost planar conformation. In the crystal, a complicated hydrogen-bonded network is formed through N—H...N/O and O—H...O intermolecular interactions. Complex (I) was also characterized by FT–IR and 1H NMR spectroscopy. It undergoes an NiII ↔ NiIII redox reaction at E 1/2 = +0.295 V (vs Ag/AgCl) in methanol solution. In a thin film with a free surface, complex (I) shows a fast photoelectric response upon exposure to visible light with a maximum photovoltage of ∼178 mV.

Crystal structure of a three-dimensional neodymium(III) coordination polymer, [Nd2(H2O)6(glutarato)(SO4)2] n

A three-dimensional coordination polymer, poly[hexaaqua(μ4-glutarato)bis(μ3-sulfato)dineodymium(III)], [Nd2(H2O)6(glutarato)(SO4)2] n (glutarato2– = C5H6O4 2–), 1, consisting of cationic {Nd2(H2O)6(SO4)2} n 2n+ layers linked by bridging glutarate ligands, was synthesized by the microwave-heating technique within few minutes. The crystal structure of 1 consists of two crystallographically independent TPRS-{NdIIIO9} (TPRS is tricapped trigonal–prismatic geometry) units that form an edge-sharing dinuclear cluster interconnected to neighbouring dimers by the μ3-SO4 2– anions, yielding a cationic two-dimensional {Nd2(H2O)6(SO4)2} n 2n+ sheet. Adjacent cationic layers are then linked via the μ4-glutarato2– ligands into a three-dimensional coordination network. Strong O—H...O hydrogen bonds are the predominant interaction in the crystal structure.

Redetermination of the structure of 2-amino-8-thia-1,5-diazaspiro[4,5]dec-1-en-5-ium chloride monohydrate

The reaction of β-(thiomorpholin-1-yl)propioamidoxime with tosyl chloride in CHCl3 in the presence of DIPEA when heated at 343 K for 8 h afforded the title hydrated salt, C7H14N3S+·Cl−·H2O, in 84% yield. This course of the tosylation reaction differs from the result of tosylation obtained for this substrate at room temperature, when only 2-amino-8-thia-1,5-diazaspiro[4.5]dec-1-ene-5-ammonium tosylate was isolated in 56% yield. The structure of the reaction product was established by physicochemical methods, spectroscopy, and X-ray diffraction. The single-crystal data demonstrated that the previously reported crystal structure of this compound [Kayukova et al. (2021). Chem. J. Kaz, 74, 21–31] had been refined in a wrong space group. In the extended structure, the chloride anions, water molecules and amine groups of the cations form two-periodic hydrogen-bonded networks with the fes topology.

Crystal structure from X-ray powder diffraction data, DFT-D calculation, Hirshfeld surface analysis, and energy frameworks of (RS)-trichlormethiazide

The structure of racemic (RS)-trichlormethiazide [systematic name: (RS)-6-chloro-3-(dichloromethyl)-1,1-dioxo-3,4-dihydro-2H-1λ6,2,4-benzothiadiazine-7-sulfonamide], C8H8Cl3N3O4S2 (RS-TCMZ), a diuretic drug used in the treatment of oedema and hypertension, was determined from laboratory X-ray powder diffraction data using DASH [David et al. (2006). J. Appl. Cryst. 39, 910–915.], refined by the Rietveld method with TOPAS-Academic [Coelho (2018). J. Appl. Cryst. 51, 210–218], and optimized using DFT-D calculations. The extended structure consists of head-to-tail dimers connected by π–π interactions which, in turn, are connected by C—Cl...π interactions. They form chains propagating along [101], further connected by N—H...O hydrogen bonds to produce layers parallel to the ac plane that stack along the b-axis direction, connected by additional N—H...O hydrogen bonds. The Hirshfeld surface analysis indicates a major contribution of H...O and H...Cl interactions (32.2 and 21.7%, respectively). Energy framework calculations confirm the major contribution of electrostatic interactions (E elec) to the total energy (E tot). A comparison with the structure of S-TCMZ is also presented.

Synthesis, crystal structure and Hirshfeld surface analysis of 1-ferrocenylundecane-1,11-diol

The racemic title compound, [Fe(C5H5)(C16H27O2)], comprises an α,ω-diol-substituted undecyl chain with a ferrocenyl substituent at at one terminus. The alkane chain is inclined to the substituted ring of the ferrocene grouping by 84.22 (13)°. The ferrocene rings are almost eclipsed and parallel. The crystal structure features O—H...O and C—H...O hydrogen bonds and C—H...π contacts that stack the molecules along the c-axis direction. A Hirshfeld surface analysis reveals that H...H interactions (83.2%) dominate the surface contacts.