Acta Crystallographica Section C Structural Chemistry最新文献

Among various glycolates, potassium glycolate glycolic acid (PGGA), ammonium glycolate glycolic acid (AGGA) and rubidium glycolate glycolic acid (RGGA) are isostructural, with the general formula A(C₂H₃O₃)(C₂H₄O₃) (A = K, NH₄ and Rb). However, whether Na⁺ can occupy the A site and its effects on structure and properties remained unknown. This study synthesized sodium glycolate glycolic acid (SGGA), analyzed its composition, structure, vibrational spectra and thermal behaviour, and compared the results with PGGA. SGGA has the formula Na⁺·C₂H₃O₃^-·C₂H₄O₃ or Na(C₂H₃O₃)(C₂H₄O₃), with orthorhombic crystallinity. Although the salt lacks chiral C atoms, it crystallizes in the unique chiral space group P2₁2₁2₁. Among various glycolates, only PGGA and RGGA display relatively similar powder X-ray diffraction (PXRD) patterns, while those of other glycolates are distinctly different, providing a key basis for distinguishing A(C₂H₃O₃)(C₂H₄O₃) glycolates. Although SGGA and PGGA show closely related vibrational spectra and thermal behaviour due to structural similarities, differences are observed in certain spectral peaks. Moreover, PGGA decomposes into carbonates at a marginally higher temperature than SGGA. This work provides insight into glycolic acid bonding and the structural role of Na⁺ in glycolates, guiding new mineral discovery.

A structural analysis is developed for five bromine-substituted ferrocenyl chalcones; the crystal structures of three of these compounds are reported for the first time. 3-(4-Bromophenyl)-1-ferrocenylprop-2-en-1-one (1), 3-(3-bromophenyl)-1-ferrocenylprop-2-en-1-one (2), 3-(2-bromophenyl)-1-ferrocenylprop-2-en-1-one (3), 1-(4-bromophenyl)-3-ferrocenylprop-2-en-1-one (4) and 1-(3-bromophenyl)-3-ferrocenylprop-2-en-1-one (5), all [Fe(C₅H₅)(C₁₄H₁₀BrO)], were synthesized via a base-catalyzed Claisen-Schmidt condensation between the corresponding ketone and aldehyde, yielding three compounds (1-3) with ferrocene attached to the carbonyl group (System 1) and two (4 and 5) with ferrocene attached to the alkene directly (System 3). Also, the position of the Br atom in the aromatic ring changes in each compound. The effect of these two parameters is evaluated considering distinct compound features, crystal packing and supramolecular features. The compounds crystallize in multiple space-group types, namely, P2₁/n (1), P2₁2₁2₁ (2), P2₁/c (3), Pca2₁ (4) and P1 (5). The majority of the intermolecular interactions arise from the ferrocene units and aromatic rings; for all compounds, the role of bromine in the crystal packing is evident by the presence of H...Br/Br...H, C...Br/Br...C and Br...Br intermolecular interactions. The position of the Br atom has effects on the crystal density, as well as the exhibited bromine interactions. The enone connectivity in System 3 for para- and meta-substituted ferrocenyl chalcones enables shorter interactions and more participation of the enone in short contacts in comparison to System 1. This is confirmed by Hirshfeld surface analysis (red spots for short contacts) and via generated two-dimensional fingerprint plots (unique features and green regions). In addition, the title compounds were analyzed by ¹H NMR, ¹³C NMR and IR spectroscopy, and melting-point analysis.

The reaction of benzhydrazide and 2-formylphenylboronic in H₂O at ambient temperature afforded the benzoyl hydrazone (E)-{2-[(2-benzoylhydrazinylidene)methyl]phenyl}boronic acid, C₁₄H₁₃BN₂O₃ (5). However, when the reaction was performed in EtOH at ambient temperature, a dimer product, namely, {oxybis[benzo[d][2,3,1]diazaborinine-1,2(1H)-diyl]}bis(phenylmethanone), C₂₈H₂₀B₂N₄O₃ (6), is the sole product isolated. Both compounds were characterized using ¹H, ¹³C and ¹¹B NMR spectroscopy, high-resolution mass spectrometry (HRMS) and single-crystal X-ray diffraction following crystallization from hot DMF/H₂O for 5 and from hot CH₃CN for 6. Benzoyl hydrazone 5 crystallized in the orthorhombic space group Pbca and revealed a strong intramolecular hydrogen-bonding interaction between the boranol O atom and hydrazonoyl N atom [H...N = 1.734 (18) Å, O...N = 2.6139 (12) Å and O-H...N = 157.4 (15)°], ensuring a near-planar benzhydrazonoyl moiety. Benzoyl hydrazone 5 packs in the solid state in dimeric assemblies through intermolecular boranol hydrogen bonds, that are further extended to two-dimensional sheets by intermolecular hydrazonoyl nitrogen to hydrazonoyl oxygen hydrogen bonds. Dimer 6 crystallized in the monoclinic space group C2/c with the borinine O atom lying on the twofold rotational axis. In contrast to the structure of benzoyl hydrazone 5, dimer 6 lacks hydrogen-bond donors and packs with an absence of intermolecular hydrogen bonding. A dative bond between the B centre and an adjacent carbonyl O atom is observed for dimer 6 [B-O = 1.574 (2) Å], enabling the formation of a [3.3.1]bicyclic system at its core. This article provides unambiguous evidence that, depending on the conditions employed, the reaction between 2-formylphenylboronic acid and benzhydrazide produces benzoyl hydrazone 5 or dimer 6 rather than 2-benzoyl-1-hydroxybenzo[d][2,3,1]diazaborine (2), despite literature reports suggesting that the latter is the case.

This article presents a comprehensive investigation involving the synthesis and characterization of three complexes obtained in an efficient one-pot synthesis using zero-valent cobalt and the proligand 1-hydroxymethyl-3,5-dimethylpyrazole (L⁰) as one of the substrates. The isolated complexes, namely, [bromido/nitrato(1.81/0.19)][tris(3,5-dimethylpyrazol-1-ylmethyl-κN²)amine-κN][cadmium/cobalt(0.96/0.04)], [Cd_0.96Co_0.04Br_1.81(NO₃)_0.19(C₁₈H₂₇N₇)] or [Cd_0.96Co_0.04L^SBr_1.81(NO₃)_0.19], 1, bis{(nitrato-κO)[tris(3,5-dimethylpyrazol-1-ylmethyl-κN²)amine-κN]cobalt(II)} tetrabromidocadmate(II), [Co(NO₃)(C₁₈H₂₇N₇)]₂[CdBr₄] or [CoL^SNO₃]₂[CdBr₄], 2, and (nitrato-κO)[tris(3,5-dimethylpyrazol-1-ylmethyl-κN²)amine-κN]cobalt(II) nitrate, [Co(NO₃)(C₁₈H₂₇N₇)]NO₃ or [CoL^SNO₃]NO₃, 3, all contain the N-scorpionate ligand N,N,N-tris(3,5-dimethylpyrazol-1-ylmethyl)amine (L^S) obtained in situ from L⁰. Compound 1 crystallizes in the monoclinic space group P2₁/n, and some positional disorder is observed at the metal ions and inorganic ligands. In contrast to 1, compounds 2 and 3 form ionic crystals and crystallize in the same type of space group (No. 15) but in different settings, i.e. C2/c and I2/a, respectively. The synthesized compounds were characterized by X-ray diffraction, elemental analysis and FT-IR spectroscopy. All the complexes presented here have good biological activity against cancer cells. Among the complexes studied, 2 and 3 are the most interesting. The interactions of isolated complexes 2 and 3 with CT-DNA were investigated using UV-Vis absorption spectroscopy and circular dichroism (CD). Isolated complexes 2 and 3 interact with CT-DNA via nonintercalatory binding modes. The results show that complex 2 combines high anticancer potency with selective action towards colorectal adenocarcinoma cells and is more effective than complex 3 and the anticancer drug cisplatin. These properties make complex 2 an interesting candidate for further investigation of specific anticancer mechanisms.

Mercaptopyridines, heteroaromatic compounds containing thiol groups, are widely studied for their applications in coordination chemistry, supramolecular design and materials science due to their selective binding properties and photoresponsiveness. In this work, we investigated the crystallization of 4-mercaptopyridine with cyanuric acid under strictly controlled conditions. A solution of both components in aqueous ethanol was subjected to UV irradiation and then allowed to crystallize slowly at 4 °C, followed by ambient conditions. Three crystalline products were isolated and were structurally characterized, namely, a cocrystal of cyanuric acid with 1,2-di(pyridin-4-yl)disulfane, C₁₀H₈N₂S₂·C₃H₃N₃O₃, (I), a cocrystal of cyanuric acid with di(pyridin-4-yl)sulfane, C₁₀H₈N₂S·C₃H₃N₃O₃, (II), and a new 3:2 cocrystal of cyanuric acid with di(pyridin-4-yl)sulfane, 2C₁₀H₈N₂S·3C₃H₃N₃O₃, (III). No crystalline material was obtained under dark conditions, and cocrystal (III) was observed only after UV irradiation, which also yielded larger and better-quality single crystals than visible light. The results are consistent with oxidative coupling of 4-mercaptopyridine in solution under the applied conditions, giving disulfane and sulfane species that subsequently cocrystallize with cyanuric acid. Two of the cocrystals correspond to previously reported forms [CSD refcodes KIRGIF and KIRGOL; Gogoi et al. (2023). J. Mol. Struct. 1289, 135806], whereas cocrystal (III) is reported here for the first time.

A novel asymmetrical bis-Schiff base, 3-({(E)-[bis(pyridin-2-yl)methylidene]hydrazinylidene}methyl)-1H-indole, C₂₀H₁₅N₅ (3-D), incorporating both pyridine and indole units, was synthesized and structurally characterized alongside its cadmium(II) complex bis[3-({(E)-[bis(pyridin-2-yl)methylidene]hydrazinylidene}methyl)-1H-indole]dichloridocadmium(II) trihydrate, [CdCl₂(C₂₀H₁₅N₅)₂]·3H₂O (3-D-Cd). Single-crystal X-ray diffraction revealed that both compounds adopt discrete molecular architectures, with the complex exhibiting pronounced π-π stacking interactions, as confirmed by density functional theory (DFT) calculations. Comprehensive spectroscopic characterization (elemental analysis, HRMS, NMR, UV-Vis and fluorescence) was performed. Cytotoxicity assays against A375, A549 and HeLa cancer cell lines, as well as normal HFF-1 cells, demonstrated that, while 3-D is minimally toxic, 3-D-Cd selectively inhibits tumour cell proliferation with significantly reduced toxicity toward normal cells compared to CdCl₂. These findings suggest the potential of 3-D as a detoxifying ligand and of 3-D-Cd as a candidate for use as a low-toxicity metal-based anticancer agent.

The crystal structure of disodium valsartan 3.5-hydrate, or poly[hemiheptaaqua[μ-5-{2-[4-({N-[(2S)-1-carboxylato-2-methylpropyl]pentanamido}methyl)phenyl]phenyl}-1H-1,2,3,4-tetrazol-1-ido]disodium], [Na₂(C₂₄H₂₇N₅O₃)(H₂O)_3.5]_n (1), was determined using powder X-ray diffraction data. Recrystallization of this substance from an ethanol-acetonitrile (1:1 v/v) mixture afforded disodium valsartan 2.67-hydrate ethanol 0.33-solvate, [Na₂(C₂₄H₂₇N₅O₃)(C₂H₅OH)_0.33(H₂O)_2.67]_n (2), with partially occupied ethanol and water positions. The crystal structure of 2 was studied using synchrotron radiation and refined as a two-component twin. The solids were found to be isotypical with four cations and two anions occupying equivalent positions (Z' = 2). The difference in the number of solvent molecules affects the coordination environment of Na2 and Na3 (Na2NO₅ and Na3NO₅ in 1, and NaNO₄/NaNO₅ for both atoms in 2 due to solvent disorder), while two other sodium ions maintain the NaN₂O₃ coordination. Valsartan acts as a dianion with both tetrazolyl and carboxyl groups deprotonated. The anions interact with sodium cations through the carboxyl, tetrazolyl and oxo groups as both bridging and bridging-chelating ligands. Bridging anions and water molecules connect both structures into infinite two-dimensional layers. The surface of these layers is hydrophobic due to the coating of alkyl and aryl groups. Numerous O-H...O and O-H...N hydrogen bonds are observed within the layers.

A new combination of molecules that form a solid solution is reported. The 2,4,6-tris(4-tert-butylphenyl)phenoxyl radical, C₃₆H₄₁O (1_M), formed two solid solutions (α and β) with its methoxy analogue 1,3,5-tris(4-tert-butylphenyl)-2-methoxybenzene, C₃₇H₄₄O (1_OMe). According to single-crystal X-ray analysis, the crystal structure of each solid solution is thought to be dominated by the characters of the main components. The β crystal (1_M:1_OMe = 0.002:0.998) is isomorphic to the crystal composed solely of 1_OMe and the molecules in the β crystal adopt the most preferred conformation for 1_OMe. In contrast, in the α crystal (1_M:1_OMe = 0.80:0.20), the molecules adopt the most preferred conformation for 1_M. However, since a crystal composed solely of 1_M has not been obtained (1_M always precipitates as a σ-dimer formed by a covalent C-O bond between the phenoxyl O atom of one molecule and the para-C atom of the central phenyl ring of another molecule), it is unclear whether it is isomorphic with the α crystal.

The crystal structures of eleven 3- and 4-pyridyl borate salts with a variety of cations are reported. These are potassium trifluoro(pyridin-3/4-yl)borate, K⁺·C₅H₄BF₃N^-, 1 and 2 (as the monohydrate), tetrabutylammonium trifluoro(pyridin-3/4-yl)borate, C₁₆H₃₆N⁺·C₅H₄BF₃N^-, 3 and 4, tetraphenylphosphonium trifluoro(pyridin-3/4-yl)borate, C₂₄H₂₀P⁺·C₅H₄BF₃N^-, 5 and 6, tetrakis(3,5-dimethoxyphenyl)phosphonium trifluoro(pyridin-3/4-yl)borate, C₃₂H₃₆O₈P⁺·C₅H₄BF₃N^-, 7 and 8, and tetrakis[4-(dimethylamino)phenyl]phosphonium trifluoro(pyridin-3/4-yl)borate, C₃₂H₄₀N₄P⁺·C₅H₄BF₃N^-, 9 and 10, and the hemihydrate, C₃₂H₄₀N₄P⁺·C₅H₄BF₃N^-·0.5H₂O, 10h. The effects of the position of the pyridine N atom and the identity of the cations on the crystal packing of the salts are examined. The N...H and F...H anion-cation contacts and the Hirshfeld surface compositions of the anions for the salts containing organic cations are compared to the reactivity of the salts in a low-polarity solvent to look for trends between solid-state features and solution-state reactivity.

In this work, we explore the structural and photoluminescent properties of 1',3',6',8'-tetramethylspiro[fluorene-9,9'-xanthene] (TMSFX), C₂₉H₂₄O. TMSFX was synthesized via a one-pot method and crystallized in the monoclinic space group P2₁/c. Single-crystal X-ray diffraction revealed a unique 90° crossover between the fluorene and xanthene segments. Photoluminescence studies showed that TMSFX exhibits strong blue-white fluorescence on excitation at 321 nm, with emission peaks at 405 and 431 nm, and a fluorescence lifetime of 3.1 ns. In contrast, the methyl-free analog spiro[fluorene-9,9'-xanthene] (SFX) is non-luminescent, highlighting the critical role of methyl groups in enhancing fluorescence. These findings demonstrate the significance of methyl groups in tuning the photophysical properties of organic molecules for potential optoelectronic applications.