Journal of Chemical Crystallography最新文献

The hydrothermal reaction of the Cd(OAc)₂ with the 2-methylimidazole (mim) in the presence of the monocarboxylic acids produced five unpublished mim-derived coordination compounds of Cd(mim)₂(ibu)₂ (1) (Hibu = ibuprofen), Cd(mim)₂(sal)₂ (2) (Hsal = salicylic acid), Cd(mim)₂(pba)₂ (3) (Hpba = 3-phenoxybenzoic acid), Cd(mim)₂(tba)₂ (4) (Htba = 2,4,6-trichlorobenzoic acid), and Cd(mim)₂(tmba)₂ (5) (Htmba = 2,4,6-trimethoxybenzoic acid) and they are structurally characterized by the EA, IR spectra, TG and SCXRD analysis. The X-ray investigations declared that all these coordination compounds demonstrated the mononuclear graphs with the pseudo-tetrahedral/octahedral/square-pyramidal geometries around the Cd²⁺. The mim molecules take the coordination mode of the monodentate by only using its imidazole ring N atoms. The CO₂⁻ coordinated to the Cd²⁺ ion in monodentate, and chelating bidentate types. The intricate intra- and intermolecular traditional H-bonds are uncovered by the X-ray crystallographic studies, which mediate the discrete systems into the 1D–2D supramolecules.

Graphical Abstract

Five mononuclear Cd²⁺ complexes with the pseudo-tetrahedral/octahedral/square-pyramidal coordination geometries have been synthesized and characterized, the intricate intra- and intermolecular traditional H-bonds mediate the discrete systems into the 1D-2D supramolecules.

The synthesis, X-ray crystallographic, and spectroscopic studies of 2-benzoylthiophene ketone thiophene-2-carboxylic acid hydrazone (bttcah) is reported. The compound crystallized by slow evaporation from ethanol in a monoclinic space group P 2₁/c with a = 9.2783(3) Å, b = 16.4236(6) Å, c = 9.8605(3) Å, β = 106.0017(12)° and V = 1444.35(8) ų with Z = 4. The thienyl rings of bttcah are pseudo-planar with the hydrazone backbone, however, the phenyl ring is out of the plane of the hydrazone backbone by 108.96^o. The packing of the molecules showed classical intermolecular hydrogen bonding between NH and C=O groups. In the ¹H NMR the NH was observed at 9.96 ppm, and in the FTIR spectrum, the ν_NH and the ν_C=O were observed at 3167 cm^–1 and 1621 cm^–1, respectively.

Graphical Abstract

The synthesis, X-ray crystallographic, and spectroscopic studies of 2-benzoylthiopheneketone thiophene-2-carboxylic acid hydrazone (bttcah) is reported

Two new 2(E)-pyranylidene-1,5-benzodiazepine derivatives, namely: 3,4-Dihydro-2-(2,4-dioxo-6-methylpyran-3-ylidene)-4-(3-pyridine-phenyl)-1,5-benzodiazepine 3 and 2(E)-3,4-Dihydro-2-(2,4-dioxo-6-methylpyran-3-ylidene)-4-(3,4,5-méthoxy-phenyl)-5-N-acetyl-1,5-benzodiazepine 6 was synthesized and characterized by NMR spectroscopy and were also analyzed by single-crystal X-ray diffraction. Their molecular packing and supramolecular features were investigated through Hirshfeld surface analysis and interaction energy calculations, which revealed dominant H···H contacts along with secondary C–H···O and π···π interactions. Molecular docking studies performed with the human α1β3γ2 GABAA receptor (PDB: 6HUO) showed favorable binding affinities, suggesting efficient interaction with the benzodiazepine binding site. Furthermore, drug-likeness and ADMET properties assessments indicate that both compounds comply with Lipinski and Veber rules, exhibit good predicted oral absorption, and are in the drug-like space. Compound 3 emerges as a promising candidate, with improved permeability and a more favorable toxicity profile. In contrast, compound 6 exhibits greater intrinsic solubility and prolonged systemic exposure, albeit with a potential hepatotoxicity signal. These results highlight the potential of 2(E)-pyranylidene-1,5-benzodiazepine skeletons as promising candidates for further biological evaluation and the design of novel GABAA receptor modulators.

The coordination chemistry of transition metals has become a promising solution to the high demand for the design of drugs for chemotherapy and radiotherapy purposes. The binding mode of various organic molecules around the fac-[Re(CO)₃]⁺ moiety has significantly contributed to the preparation of various coordination compounds with a variety of specific applications. Herein, we report the synthesis and characterization of a non-radioactive rhenium complex fac-[Re(CO)₃(H₂dpp)Cl] (1) that was isolated from the reaction of Re(CO)₅Cl with a heterocyclic tetraamine compound, (8E,10E)-1,4,8,11-tetraazacyclotetradeca-8,10-diene (H₂tazd) in toluene. The crystals of compound 1 were crystallographically analysed using single X-ray diffraction techniques. The crystal structure of compound (1) is dominated by the unusual in situ ring rearrangement/reduction of the used H₂tazd ligand into the saturated and coordinated dodecahydropyrimido[2’,1′:3,4]pyrazino[1,2-a]pyrimidine (H₂dpp) ligand. This complex is a monomeric rhenium complex with H₂dpp coordinating neutrally as a bidentate N,N′-donor chelate. The coordinated chelate; H₂dpp is also a result of the intramolecular conversion process via the new C–N bond formation leading to a system with three fused rings. The refinement of compound 1 predicts the ring formation in the ligand, and this phenomenon is rare in the coordination chemistry of rhenium and was probably catalysed by rhenium(I) in the complex.

Graphical abstract

A heterotrimetallic aluminum-dysprosium-sodium 12-MC-4 complex, Dy^IIINa(ben)₄[12-MC_{Al(III)N(5−nitroshi)}-4](H₂O)_3.58(DMF)_2.44·7.86DMF·0.28H₂O (1), where DMF is N,N-dimethylformamide, with the metallacrown (MC) framework ligand 5-nitrosalicylhydroximate (5-nitroshi³⁻) and the ancillary bridging ligand benzoate (ben⁻) has been synthesized and characterized by FT-IR and single-crystal X-ray diffraction. The MC framework ligand 5-H₃nitroshi is a derivative of the common MC ligand salicylhydroxamic acid (H₃shi), and this is the first instance of 5-H₃nitroshi being used for a metallacrown. The MC ring consists of four Al^III ions, and the MC binds one Dy^III ion on the convex side of the central cavity. Four benzoate anions tether the Dy^III ion to the MC cavity by forming a bridge between each ring Al^III ion and the central Dy^III ion. The position of the Na⁺ ion is unique regarding this class of 12-MC-4 complexes as the sodium ion is disordered over four binding sites on the MC. The main occupancy [0.326(3)] of the sodium ion is located on the concave side of the MC central cavity, opposite of the Dy^III ion. This location is typical for this class of 12-MC-4 molecules. The other three binding sites occur of the periphery of the molecule, and the sodium ion binds to phenolate and carbonyl oxygen atoms of the 5-nitroshi³⁻ MC framework ligands. The coordination environments of each sodium ion are completed by a mixture of water and DMF solvent molecules. The total occupancy of the sodium ion sites is unity.

The heterotrimetallic Dy^IIINa(ben)₄[12-MC_{Al(III)N(5-nitroshi)}-4] complex is constructed with the metallacrown framework ligand 5-nitrosalicylhydroxamic acid (5-H₃nitroshi). The sodium cation is disordered over four different binding sites

The synthesised complex [OsBr₂(CO)₂(PBz₃)₂], crystallises in the monoclinic, space group C2/c (no. 15), a = 23.3375(14) Å, b = 18.3044(10) Å, c = 9.4310(6) Å, α = γ = 90°, β = 98.962(2)°, V = 3979.5(4) ų, Z = 4. The bulky PBz₃ ligand imposes a significant steric effect on the metal centre, as reflected by a buried volume of 24.0% in the title compound, with a cone angle of 213.51˚.

Graphical Abstract

The ongoing investigation of a copper (II) complexes has led to the development of novel hydrogen-bonded metal–organic frameworks (HBMOFs). In the present work, a copper (II) pyridine dicarboxylic acid, Cu(HPDCA)₂(H₂O)₂, is reacted with phenethylamine to yield a lamellar framework featuring an octahedral geometry across the copper (II) center. The incorporation of phenethylamine results in an extended interlayer separation relative to previously reported HBMOFs. This layered architecture is capable of accomodating a range of guest molecules, including both alkyl and benzyl alcohols. Herein, we report the structutal characterizations of four guest-included hydrogen-bonded frameworks, compared against the corresponding guest-free framework: (1) [phenethylammonium]₂Cu(PDCA)₂(H₂O)₂, (2) [phenethylammonium]₂Cu(PDCA)₂(H₂O)₂·(1-pentanol), (3) [phenethylammonium]₂Cu(PDCA)₂(H₂O)₂·(1-hexanol), (4) [phenethylammonium]₂Cu(PDCA)₂(H₂O)₂·(benzyl alcohol), (5) [phenethylammonium]₂Cu(PDCA)₂(H₂O)₂·(4-chlorobenzylalcohol).

Graphical Abstract

Lamellar Hydrogen-Bonded Metal-Organic Framework (HBMOF)

Chromene-based spiroketals are valuable structural motifs in medicinal and synthetic organic chemistry; however, their reported syntheses typically require multi-step routes and harsh reaction conditions. In this work, a simple, efficient, and cost-effective one-pot method for the synthesis of ethyl 2,2′-spirobi[chromene]-3-carboxylate is presented. The compound was obtained via the acid-catalyzed condensation of salicylaldehyde with ethyl acetoacetate in methanol using only a few drops of H₂SO₄, affording the spiroketal framework in a single step under mild conditions. Structural elucidation was performed using comprehensive spectroscopic techniques, including FTIR, HR-MS, and 1D/2D NMR analyses. Given the novelty of the compound, detailed 2D NMR (HSQC, HMBC, and COSY) studies were carried out to unambiguously assign proton and carbon resonances within the spiro-linked chromene units. The molecular structure was further confirmed by single-crystal X-ray diffraction, providing definitive evidence of the spiro-fused architecture. Elemental analysis supported the purity and composition of the synthesized product. This streamlined synthetic strategy offers an attractive alternative to conventional routes and may provide a useful platform for the development of new chromene-based spiroketal derivatives.

Graphical Abstract

Hybrid organic-inorganic metal halide materials attract attention due to their potential optoelectronic applications. In this report, we undertook the follow-up characterization of the hybrid material (C₂H₅NH₃)₂[SbBr₅]. Crystallographic characterization showed that this compound consists of corner-sharing SbBr₆ octahedra, which form zig-zag chains that are separated by the organic molecules. We found that, unlike in the previous study, the organic molecules do not exhibit an apparent disorder. Infrared (IR) and Raman spectroscopy confirm the composition of this compound. To further explore the material’s properties, we prepared two samples with and without Te. UV-Vis spectroscopy showed the bandgap of the material changed by approximately 0.30 eV upon tellurium incorporation. To elaborate on this effect, we performed DFT calculations for both the doped and undoped chemical systems. These calculations agreed well with our experimental observations and support the notion that tellurium causes a bandgap reduction in (C₂H₅NH₃)₂[SbBr₅].

Graphical Abstract

The crystal structure of (C2H5NH3)2[SbBr5] was re-evaluated, and the spectral characterization of this compound was made.