Acta Crystallographica Section C Structural Chemistry最新文献

The reaction of decafluorobenzophenone [perfluorobenzophenone, (C₆F₅)₂CO] with AsF₅ in anhydrous HF yields the protonated salt [bis(2,3,4,5,6-pentafluorophenyl)methylidene]oxidanium hexafluoridoarsenate, (C₆F₅)₂COH⁺[AsF₆]^-, whereas its reaction with AsF₅ in SO₂ affords the Lewis acid-base adduct decafluorobenzophenone-arsenic pentafluoride, (C₆F₅)₂CO·AsF₅. In both compounds, the decafluorobenzophenone moiety exhibits an elongated C=O bond [1.274 (2) and 1.2526 (15) Å in the salt and adduct, respectively]. The crystal structure of (C₆F₅)₂COH⁺[AsF₆]^- features a short O-H...F hydrogen bond between the cation and the anion, and the crystal structure of (C₆F₅)₂CO·AsF₅ represents a rare example of a ketone coordinated to the strong Lewis acid AsF₅.

The structures of six triperiodic CuCN network structures with conjugate acids of four N-alkylethanolamines as guest cations are described, namely, poly[2-hydroxyethan-1-aminium [μ₃-cyanido-di-μ₂-cyanido-dicuprate(I)]], {(C₂H₈NO)[Cu₂(CN)₃]}_n, 1, poly[bis(2-hydroxy-N-methylethan-1-aminium) [di-μ₃-cyanido-tri-μ₂-cyanido-tricuprate(I)] monohydrate], {(C₄H₁₂NO)₂[Cu₃(CN)₅]·H₂O}_n, 2, poly[tetrakis[N-(2-hydroxyethyl)ethan-1-aminium] [chloridotetra-μ₃-cyanido-penta-μ₂-cyanido-tricuprate(I)]], {(C₄H₁₂NO)₄[Cu₆(CN)₉Cl]}_n, 3, poly[tetrakis[N-(2-hydroxyethyl)ethan-1-aminium] [penta-μ₃-cyanido-hepta-μ₂-cyanido-octacuprate(I)]], {(C₄H₁₂NO)₄[Cu₈(CN)₁₂]}_n, 4, poly[2-hydroxy-N,N-diisopropylethan-1-aminium [μ₃-cyanido-μ₂-cyanido-dicuprate(I)] monohydrate], {(C₈H₂₀NO)[Cu₃(CN)₄]·H₂O}_n, 5, and poly[2-hydroxy-N,N-diisopropylethan-1-aminium [μ₃-cyanido-di-μ₂-cyanido-dicuprate(I)]], {(C₈H₂₀NO)[Cu₂(CN)₃]}_n, 6. In five of the structures (1-5), the CuCN network includes Cu atoms occurring in pairs, linked by cuprophilic interactions. Analysis with the intent of exploring the `template effect' of the cations on the CuCN network structure indicated five separate CuCN topologies. The two different crystal structures involving cations from N-ethylethanolamine have the same basic topology, whereas the two crystal structures involving cations from N,N-diisopropylethanolamine have different topologies, contrary to what might be expected from a template effect. Thermogravimetric analysis of the compounds usually shows loss of HCN(g) and the free base by 200 °C, with a CuCN(s) residue, but decomposition of one of the structures is more complex.

Bis[bis(ethylenedithio)tetraselenafulvalene(0.5+)] dibromidoaurate(I) and its chloride analogue, (C₁₀H₈S₄Se₄)₂[AuX₂] or BETS₂AuX₂ (X = Cl and Br), were synthesized to examine their crystal and band structures. The crystal structures are new in that they have both structural features of different types of organic Dirac electron systems (ODES), i.e. α- and α'-type iodine-centred trihalide (IX₂^-) salts of BETS-related electron-donor molecules. The former often produces zero-gap semiconductors, while the latter is related to nodal-line semimetals, i.e. classes of ODES different from each other. The band structure calculation suggests that BETS₂AuX₂ are close to zero-gap semiconductors, indicating that the α-type structural feature governs the band structures in these salts. Although the dimensions and geometries of the constituents are close to each other between BETS₂IX₂ and BETS₂AuX₂, the strength of the BETS-anion interaction resulted in a difference in the crystal structures between the α- and α'-type molecular arrangements. Our findings show that the crystal and band structures are affected by the electronic states of the constituents sometimes more than one would expect based on their geometrical features.

This article focuses on a specific real-space methodology for solving and refining molecular organic crystal structures, developed by the authors and collaborators. It outlines a practical route from polycrystalline samples to refined crystal structures, emphasizing efficient global optimization by DASH and the robust refinement capabilities of TOPAS. The approach prioritizes laboratory-to-laboratory reproducibility via a standardized workflow that addresses key challenges in molecular organic crystal structure determination.

Stimuli-responsive crystalline materials have demonstrated significant potential for developing multifunctional systems. Achieving precise structural modulation in non-porous crystalline phases remains a critical challenge, particularly in correlating molecular-level conformational changes with macroscopic properties. Here, we report a solvatomorphic crystalline system, (1-azabicyclo[2.2.2]octane-κN){4,4',6,6'-tetra-tert-butyl-2,2'-[1,2-phenylenebis(nitrilomethylidyne)]diphenolato-κ⁴O,N,N',O'}zinc(II) acetonitrile monosolvate, [Zn(C₃₆H₄₆N₂O₂)(C₇H₁₃N)]·CH₃CN or [Zn(saloph)](quinuclidine)](acetonitrile) (1·solvent), which exhibits a reversible single-crystal-to-single-crystal transformation during acetonitrile adsorption/desorption. Structure analysis reveals that solvation dynamics induce a pronounced variation in the dihedral angle of the [Zn(saloph)] coordination centre, accompanied by a luminescence red shift of approximately 10 nm. This work establishes a strategy for modulating optoelectronic properties in non-porous crystalline materials through solvent-mediated structural reorganization, advancing the development of stimuli-responsive functional materials.

Two 1:1 cocrystals of imidazo[1,2-a]pyridine-3-carbonitrile (IPC) with 4-nitrobenzoic acid (4-NBA) and 4-nitrophenol (4-NP), namely, imidazo[1,2-a]pyridine-3-carbonitrile-4-nitrobenzoic acid (1/1), C₈H₅N₃·C₇H₅NO₄ or (IPC)·(4-NBA) (I), and imidazo[1,2-a]pyridine-3-carbonitrile-4-nitrophenol (1/1), C₈H₅N₃·C₆H₅NO₃ or (IPC)·(4-NP) (II), were obtained and their crystal structures determined by single-crystal X-ray diffraction. Molecules of I and II are both linked by O-H...N, C-H...O and C-H...N hydrogen bonds to form two-dimensional planes, which are further connected into three-dimensional frameworks by C-H...π interactions (in I) and π-π interactions (in II).

The extraction and separation of rare earth elements (lanthanides) can be difficult due to their chemical similarities. Biological processes can have very selective activity towards different elements. We investigated the use of microalgae for this purpose by looking at the interaction of Ce, Gd and Yb with the microalga Chlamydomonas reinhardtii, which has been induced to form polyphosphate granules. X-ray absorption spectroscopy with XANES and EXAFS at the Ce L₃-edge, Gd L₃-edge and Yb L₃-edge was used to characterize the interaction between the lanthanides and the phosphate-containing algae. All three of the lanthanides, added as the chloride salt to the algae, appeared to react to form phosphate compounds. These form both in the presence of phosphate granules or when there is only a low level of P present. CePO₄ could be determined by XANES, but the structures of GdPO₄ and YbPO₄ were determined by EXAFS analysis without reference to the XAS spectra of the standard compounds. It is proposed that C. reinhardtii or other similar microalgae may be useful in the selective removal of rare earths from solution.

The HIV-1 protease inhibitor indinavir sulfate was cleaved via a one-pot reflux synthesis using 1-propanol, yielding the salt bis(2-hydroxy-2,3-dihydro-1H-inden-1-aminium) sulfate, 2C₉H₁₂NO⁺·SO₄^2-. Single-crystal X-ray diffraction (SC-XRD) revealed that the salt crystallizes in the monoclinic space group P2₁. The structure consists of two conformationally distinct cations and one sulfate anion, stabilized through an extensive hydrogen-bonding network. Thermal analysis showed minor solvent loss around 200 °C, followed by a two-step decomposition process commencing at 306.6 °C. Hirshfeld surface analysis revealed dominant O...H/H...O (44.4-41.0%) and H...H (45.2-40.1%) intermolecular contacts, with minor contributions from C...H/H...C and C...O/O...C interactions. These contact percentages were calculated for each of the two independent cations. The van der Waals surface area (687.30 Ų) accounts for 71.43% of the unit cell. These results provide structural and thermal evidence for the transformation of indinavir sulfate under alcoholytic conditions, highlighting the formation and stabilization of the resulting salt.

The crystal structure of the ortho-isomer trans-[N-(2-bromo-3,4,5,6-tetrafluorophenyl)-N',N'-diethylethane-1,2-diaminato(1-)]chloridopyridineplatinum(II), [PtBr_0.1(C₁₂H₁₄BrF₄N₂)Cl_0.9(C₅H₅N)][PtBr_0.4(C₁₂H₁₄BrF₄N₂)Cl_0.6(C₅H₅N)] or [Pt{(o-BrC₆F₄)N(CH₂)₂NEt₂}Cl(py)], 1o, revealed syn and anti rotamers in a 1:1 ratio in the solid state. 1o crystallizes in the centrosymmetric space group P1. The Pt-coordinated Cl ligand exhibits partial occupancy with Br, predominantly in the syn-rotamer. Notably, agostic interactions are observed between the Pt centre and a H atom of one of the ethyl groups. The ortho-isomer 1o was successfully isolated as a side product from the reaction of [Pt{H₂N(CH₂)₂NEt₂}Cl₂], Tl₂CO₃ and C₆F₅Br. While the para-isomer [Pt{(p-BrC₆F₄)N(CH₂)₂NEt₂}Cl(py)], 1p, is the main product, the higher solubility of 1o facilitates its isolation.

The crystalline form of sparsentan (SST) (systematic name: 2-{4-[(2-butyl-4-oxo-1,3-diazaspiro[4.4]non-1-en-3-yl)methyl]-2-(ethoxymethyl)phenyl}-N-(4,5-dimethyl-1,2-oxazol-3-yl)benzenesulfonamide), C₃₂H₄₀N₄O₅S, was produced and characterized using single-crystal and powder X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and IR spectroscopy. The SST molecule displays positional disorder in three different sections. Viability tests of alternative disorder models involved the calculation of energetic contributions to analyse each possible molecular conformation within its crystal environment and identify the energetically most favourable conformations in the lattice.