The title coordination complex tetra-chlorido-bis-(1H-imidazo[4,5-b]pyridin-4-ium-κN 3)iron(II), [FeCl4(C6H6N3)2] or [FeCl4(LH)2], was synthesized and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in the triclinic space group P1. The iron atom (site symmetry ) is hexa-coordinated, adopting a slightly distorted octa-hedral geometry defined by two 1H-imidazo[4,5-b]pyridinium ligands and four chloride anions. In the crystal, N-H⋯Cl hydrogen bonds generate two-dimensional layers parallel to the ab plane, while the three-dimensional supra-molecular framework is further consolidated by C-H⋯Cl inter-actions. In addition, π-π stacking inter-actions contribute to the overall cohesion of the crystal structure. Hirshfeld surface analysis indicates the significance of various inter-molecular contacts in the crystal packing, with major contributions from Cl⋯H/H⋯Cl (43.2%), H⋯H (22.5%), C⋯H/H⋯C (16.4%), H⋯N/N⋯H (4.4%), N⋯C/C⋯N (3.7%), C⋯C (3.6%), Cl⋯N/N⋯Cl (3.2%), Cl⋯C/C⋯Cl (2.4%), and N⋯N (0.6%) inter-actions.

The title coordination complex tetrachloridobis(1 H -imidazo[4,5- b ]pyridin-4-ium-κ N 3 )iron(II), [FeCl 4 (C 6 H 6 N 3 ) 2 ] or [FeCl 4 (LH) 2 ], was synthesized and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in the triclinic space group P 1 . The iron atom (site symmetry \overline{1}) is hexa-coordinated, adopting a slightly distorted octahedral geometry defined by two 1 H -imidazo[4,5- b ]pyridinium ligands and four chloride anions. In the crystal, N—H...Cl hydrogen bonds generate two-dimensional layers parallel to the ab plane, while the three-dimensional supramolecular framework is further consolidated by C—H...Cl interactions. In addition, π–π stacking interactions contribute to the overall cohesion of the crystal structure. Hirshfeld surface analysis indicates the significance of various intermolecular contacts in the crystal packing, with major contributions from Cl...H/H...Cl (43.2%), H...H (22.5%), C...H/H...C (16.4%), H...N/N...H (4.4%), N...C/C...N (3.7%), C...C (3.6%), Cl...N/N...Cl (3.2%), Cl...C/C...Cl (2.4%), and N...N (0.6%) interactions.

Advancing structure-packing-morphology correlations in beta-diketonate complexes provides a rigorous framework for how local coordination geometry propagates into supramolecular organization and ultimately governs macroscopic form. Within this context, we report the synthesis, single-crystal and powder X-ray diffraction analysis, targeted CSD mining, BFDH morphology modeling, and complementary quantum calculations of a new cobalt(II) benzoylacetonate, [Co(bzac)2]. Accurate SC-XRD data at 100 K establish a centrosymmetric trans-CoO4 chromophore in P21/n with a quasi square-planar coordination environment, while PXRD confirms phase purity. In the solid state, [Co(bzac)2] forms directionally coherent zigzag stacks consistent with its experimentally observed acicular habit. A comparative CSD-survey across [M(bzac)2] (M= Pb, Sn, Pdtrans, Pdcis, Cu) reveals metal-dependent variations in stereochemistry, chelate planarity, and packing, positioning the cobalt complex at the most planar and structurally coherent limit. BFDH analysis uncovers a monotonic increase in growth anisotropy culminating in [Co(bzac)2], whose short pi-pi, metal-pi, and C-Hpi contacts rationalize its needle-like morphology. FTIR confirms enolization and O,O '-chelation, while UV-vis spectra display ligand-centered pi -> pi* and n -> pi* transitions. DFT reproduces the experimental symmetry and electronic partitioning, and TD-DFT recovers the absorption envelope. Overall, the integrated SC-XRD <-> CSD <-> BFDH <-> DFT workflow establishes [Co(bzac)2] as a crystallographic, morphological, and electronic benchmark within the family.

A novel organic-inorganic hybrid compound, 1-[2-pyridylazo]-2-naphthol-hydroselenate monohydrate (PANHSW), was synthesized through a proton transfer reaction between PAN and selenic acid. The structural characterization of the compound was performed using single-crystal X-ray diffraction, revealing a triclinic crystal system (space group P1̅) with layered packing stabilized by π–π stacking and hydrogen bonding interactions. Infrared (IR) spectroscopy supported the presence of key functional groups, and theoretical vibrational analysis via DFT/B3LYP/6-31G(d, p) further confirmed structural assignments. Hirshfeld surface and fingerprint plot analyses indicated that O···H/H···O and H···H interactions contribute most to the packing stability. Frontier molecular orbital, natural bond orbital, and molecular electrostatic potential analyses provided insight into the compound’s electronic behavior, suggesting significant intramolecular charge transfer and moderate electrophilic character. The HOMO–LUMO energy gap (3.39 eV) implied high kinetic stability. Additionally, molecular docking simulations were performed against four predicted protein targets: TLR9, PDE7A, AHR, and PPARG. Among these, PANH⁺ showed the most promising and functionally relevant binding with PDE7A, engaging active site residues through π–π and electrostatic interactions. Interactions with TLR9, AHR, and PPARG were found to be peripheral or outside active regions. These findings collectively highlight the structural stability and potential biological relevance of PANHSW, paving the way for future studies into its pharmacological or sensing applications.

Bringing light responsiveness and single-molecule magnet behaviour into true cooperation has long been a central ambition. In the hetero-tetrametallic Mo(CuLnCo) 2 complex (Ln = Gd 3+ , Tb 3+ ), such synergy is achieved through a rational modular design in which each metal ion has a role to play. A photo-switching octacyanido Mo core is connected to two Schiff-base CuLn units, each capped by a Kläui metalloligand that tailors the lanthanoid environment to form the CuLnCo branch. Reversible light-induced bond cleavage at the Mo centre, associated with a singlet-to-triplet transition, introduces exchange interactions and generates a high spin state in the isotropic Gd species, while directly modulating magnetic relaxation in the Tb-based SMM. This interplay highlights a promising strategy for creating multifunctional molecules with cooperative, tuneable behaviour.

Hetero-tetra-metallic complexes, FeNOCuLnCo (Ln=Gd, Tb, Dy), combining magnetic properties and photo-isomerism, were obtained through the rational assembly of the photo-switching nitroprusside anion FeNO with new magnetic Schiff base CuLnCo precursors. Herein, we describe the synthesis and characterisation of these compounds followed by a demonstration of their multifunctional character. Particularly noteworthy is the FeNOCuTbCo complex which is one of the few examples of a photo-isomerisable SMM.

Both enantiomers (S,S) and (R,R) of the chiral mixed-valence radical cation salts (DM-EDT-TTF)2XO4 (X = Cl or Re) have been prepared by electrocrystallization. Single-crystal high-quality synchrotron radiation data allowed for the very accurate determination of their 298 and 18 K structures. At room temperature, they crystallize in the enantiomorphic space groups P6222 and P6422 for the (S,S) and (R,R) enantiomers, respectively, while at 18 K, the structures have been solved in the P62 and P64 space groups, respectively. This symmetry reduction results in a quadrupled unit cell containing four independent donors disordered over two inequivalent positions. In the perrhenate salts, there is strong structural evidence of the occurrence of charge ordering at 18 K as suggested by the alternation of charge-rich and charge-poor donors within the stacks. The easier establishment of charge disproportionation is very likely related to the higher metal-to-insulator transition temperature for perrhenate compared to perchlorate, as observed in the electrical resistance measurements. Spin-polarized DFT band structure calculations support the magnetic ground state of the materials and the activated low-temperature conductivity as a consequence of gap opening. Single-crystal Raman spectroscopy measurements indicate a stronger charge ordering degree at 10 K for the perrhenate than for the perchlorate salts. For the first time in chiral TTF-based conductors, the chirality-induced spin selectivity (CISS) effect is demonstrated through magnetoresistance measurements at room temperature on thin crystals of (DM-EDT-TTF)2ClO4, with a value of up to 30% for CISS-induced magnetoresistance.

The exploration of novel nonlinear optical (NLO) materials is essential for advancing photonic and optoelectronic technologies. Within this context, we report in this work, the synthesis, crystallization, and NLO properties of three novel semi-organic compounds: o-carboxyanilinium hydrogen selenite (1), m-carboxyanilinium hydrogen selenite (2), and p-carboxyanilinium hydrogen selenite (3). These compounds were synthesized using an aqueous-phase grafting technique, producing distinct crystalline structures: monoclinic P 2 1 for 1 , monoclinic P 2 1 / n for 2 , and triclinic P 1 for 3 . Single crystal X-ray diffraction revealed unique intra- and intermolecular interactions with significant implications for their optical properties. UV-Vis spectroscopy indicated broad absorption bands, varying among the compounds, and NLO measurements showed remarkable third harmonic generation (THG) and second harmonic generation (SHG) efficiencies, particularly for 1 . First-principles calculations using DFT were performed to gain deeper insights into the structure-property relationship of these hybrids. These calculations confirmed the significant THG and SHG responses of 1 due to its favorable electronic structure and intermolecular interactions. Additionally, Bond Valence Sum (BVS) calculations were conducted to confirm the valence state of selenium in the HSeO3- anion, further supporting the structural integrity and stability of the compounds. HS analysis, combined with a meticulous examination of structure-property relationships, elucidated the role of H-bonding and pi-pi interactions in stabilizing the crystal lattice and underscored the critical influence of crystal symmetry, molecular conformation, and intermolecular interactions on the NLO performance. These findings offer valuable insights into the structural attributes and nonlinear susceptibilities of these hybrids. This work provides a deeper understanding of the design and behavior of semi-organic materials regarding their nonlinear optical properties.

Mesoporous bioactive glasses (MBGs) have been reported as promising biomaterials to stimulate and promote the growth of bones. When exposed to Simulated Body Fluid (SBF), MBGs develop an apatite phase called carbonate hydroxyapatite (H(C)A) on their surfaces that closely mimics the mineral phase of bones. In order to gain deeper insights into the key stages of the surface reactions of two different types of MBGs (58S and 70S30C) soaked in SBF, we have used high energy total X-ray scattering coupled to Pair Distribution Function (PDF) analysis, along with Raman spectroscopy and scanning electron microscopy. This type of coupled analytical approach can ultimately help to unravel the details of the reaction kinetics in the complex calcium phosphate environment around the BGs surfaces. The data obtained in our in-vitro study point to the formation of other intermediate phases like amorphous calcium phosphate (ACP) and calcite (CC), that transform after a specific time into H(C)A depending on the composition of the MBGs, their surface properties and their interaction times with SBF.

In the title compound, C20H18O4, the dihedral angle between the 2H-chromen-2-one ring system and the phenyl ring is 89.12 (5)°. In the crystal, the molecules are connected through C—H...O hydrogen bonds to generate [010] double chains that are reinforced by weak aromatic π–π stacking interactions. The unit-cell packing can be described as a tilted herringbone motif. The H...H, H...O/O...H, H...C/C...H and C...C contacts contribute 46.7, 24.2, 16.7 and 7.6%, respectively, to its Hirshfeld surface.

The performance of different density functional tight binding (DFTB) methods for the description of six increasingly complex metal-organic framework (MOF) compounds have been assessed. In particular the self-consistent charge density functional tight binding (SCC DFTB) approach utilizing the 3ob and matsci parameter sets have been considered for a set of four Zn-based and two Al-based MOF systems. Moreover, the extended tight binding for geometries, frequencies, and noncovalent interactions (GFN2-xTB) approach has been considered as well. In addition to the application of energy minimizations of the temperature and pressure conditions (298.15 K, 1.013 bar) have been carried out to assess the performance of the different DFTB methods at nonzero thermal conditions. In order to obtain the XRD patterns from the MD simulations, a flexible workflow to obtain time-averaged XRD patterns from (in this study 5000) individual snapshots taken at regular intervals over the simulation trajectory has been applied. In addition, the comparison of pair-distribution functions (PDFs) directly accessible from the simulation data shows very good agreement with experimental reference data obtained via measurements employing synchrotron radiation in case of MOF-5. The comparison of the lattice constants and the associated X-ray diffraction (XRD) patterns with the experimental reference data demonstrate, that the SCC DFTB approach provides a highly efficient and accurate description of the target systems.

We have shown in a previous work that the combination of the emulsion solvent evaporation technique and droplet-based microfluidics allows for the synthesis of well-defined monodisperse mesoporous silica microcapsules (hollow microspheres), whose size, shape and composition may be finely and easily controlled. In this study, we focus on the crucial role played by the popular Pluronic® P123 surfactant, used for controlling the mesoporosity of synthesised silica microparticles. We show in particular, that although both types of initial precursor droplets, prepared with and without P123 meso-structuring agent, namely P123+ and P123− droplets, have a similar diameter (≃30 μm) and a similar TEOS silica precursor concentration (0.34 M), the resulting microparticles exhibit two noticeably different sizes and mass densities. Namely, 10 μm and 0.55 g/cm3 for P123+ microparticles, and 5.2 μm and 1.4 g/cm3 for P123− microparticles. To explain such differences, we used optical and scanning electron microscopies, small-angle X-ray diffraction and BET measurements to analyse structural properties of both types of microparticles and show that in the absence of Pluronic molecules, P123− microdroplets divide during their condensation process, on average, into three smaller droplets before condensing into silica solid microspheres with a smaller size and a higher mass density than those obtained in the presence of P123 surfactant molecules. Based on these results and on condensation kinetics analysis, we also propose an original mechanism for the formation of silica microspheres in the presence and in the absence of the meso-structuring and pore-forming P123 molecules.

A new conjugated chalcone compound (Z)-2-(1-(1-(2,4-dimethylphenyl)-3-oxo-3-phenylprop-1-en-2-yl)pyridin-2 (1H)ylidene) malononitrile was prepared and structurally analyzed using single-crystal X-ray diffraction. This new compound's quadratic and cubic susceptibilities at 1064 nm were analyzed and evaluated using the second and third harmonic generation methods after deposition in PMMA polymer thin films. These films have been used for the induced second harmonic generation measurements achieved using the corona poling technique. Complementary information on electric dipole moment, static dipole polarizability, and initial hyperpolarizability of this compound were obtained from the density functional theory (DFT) calculation performed at the DFT/B3LYP/6-311G++ (d, p) and Gaussian 09 software. The findings demonstrate that when compared to previous chalcone NLO crystals that have been published, the synthesized crystals had greater crystal transparency, polarizability, and pi-conjugation. In particular, the (Z)-2-(1-(1-(2,4-dimethylphenyl)-3-oxo-3-phenylprop-1-en-2-yl)pyridin-2(1H)ylidene) malononitrile crystal's SHG and THG susceptibility are 0. 243 [pmV-1] and 41.13 10- 22 [m2V-2], respectively. The combined findings demonstrate that the NLO properties depend only on the steric hindrance and the chemical structure, that is, the system of pi-conjugated electrons.

In this work, we reported the experimental study of two new complexes named bis[chloro(1-methyl-1H-imid-azole-2-carbaldehyde oxime) Nickel(II) {Ni(L)2Cl2} (I) and Di-mu-chloro-bis[chloro(1-methyl-1H-imidazole-2-carbaldehyde oxime) mercury(II) {Hg2(L)2Cl4}, DMF (II) based on (1-methylimidazole-2-aldoxime, L). The synthesis, crystallization, and characterization were detailed. Complex I display a hexa-coordinated compound with a distorted octahedral geometry. The NiII ion is coordinated to two ligands in bidentate mode through nitrogen atoms. Complex II has one unique HgII atom and forms a dimeric complex that contains two HgII atoms related by a crystallographic inversion center. In this complex, the oxime ligand is ligated to the metal ion in a monodentate fashion through the nitrogen atoms. On the basis of bond distances, this complex exhibits a dis-torted tetrahedral geometry around each mercury center metal. The complexes are analyzed using single-crystal diffraction, FT-IR, NMR, and UV-visible. Cyclic voltammetry was also used to understand the electrochemical behavior of the ligand and both complexes. Furthermore, we have performed DFT calculations to get more about the spectral electronic transitions' nature, reactivity, and electronic structure of the ligand and complexes.

Exploiting new polymorphs of active pharmaceutical ingredients (APIs) has a significant role in the development of new processes for the pharmaceutical industry.

Diethylenetriammonium nitrato-bis(oxalato)cuprate (II) dihydrate (H3dien)[Cu(NO3)(C2O4)2].2H2O (1) was synthesized by wet chemistry method. It was assessed for thermal stability (TG-DTA), single crystal X-ray diffraction, Fourier Transform Infrared spectroscopy (FTIR) and magnetic measurements. 1 crystallizes in the monoclinic system (P21/c), with the parameters: a = 10.1054(5) & ANGS;, b = 11.0825(5) & ANGS;, c = 14.8238(7) & ANGS;, & beta; = 103.516(5)degrees, V = 1614.2 (1) & ANGS;3 and Z = 4. The complex anions are distributed into layers, whilst the self assembly of the inorganic-organic entities is assured by an intricate hydrogen network. At 413 K, the thermal behavior predominantly consists of the removal of water molecules, while its infrared spectrum displays distinct bands of oxalate, nitrate and diethylenetriamine groups. The catalytic test indicated that complex 1 exhibits a good catalytic activity in nitrophenol isomers (NP) reduction to aminophenols (AP). Moreover, 1 showed a high photocatalytic degradation efficiency 90% at 90 min toward the methylene blue (MB) dye under the UV irradiation. Due to the presence of the heteroatoms in its structure, the examined hybrid material's corrosion inhibiting action in acidic conditions was more pronounced.

The solid-state landscape of proxyphylline (PXL), a chiral derivative of theophylline crystallizing as a racemic compound, was extensively investigated by means of thermal analyses and diffraction techniques. This study revealed the presence of five distinct polymorphic forms that were characterized: two polymorphs of the racemic mixture and three polymorphs of the pure enantiomer. The nature of each solid phase was confirmed by combining the different analytical techniques, revealing the presence of a thermodynamically stable racemic compound, RI (TFus= 134 °C), in equilibrium with the stable enantiopure crystal form, EI (TFus = 148.3 °C). Additionally, other crystal forms could be evidenced: a polymorph of the racemic compound, RII (TFus= 111.5 °C), as well as two metastable conglomerates, cEI and cEII, and two other polymorphs of the pure enantiomer, EII and EIII. The crystal structures of RI and EI are reported and discussed, highlighting the diversity of molecular conformations that can be adopted by the PXL molecule, which accounts for the versatility of the crystallization behaviors observed in this system. These findings enhance our understanding of the crystallization behavior of chiral pharmaceutical compounds and have implications for optimizing their crystallization processes in the pharmaceutical industry.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Using ethylenediamine (en) as a structure-directing agent, a novel hybrid decavanadate (diethylenediammonium diammonium decavanadate tetrahydrated) (NH4)2(H2en)2{V10O28}.4H2O has been synthesized via a slow evaporation approach. A low-temperature single-crystal X-ray diffraction investigation was used to investigate its structural structure. Its crystal structure was studied using a low-temperature single-crystal X-ray diffraction analysis showing a crystallization in the triclinic system (S.G. P-1) with the following unit cell parameters (angstrom, degrees) a = 8.4975 (2), b =10.2550 (3), c =10.9165 (3), alpha =103.950 (2), beta = 98.466 (2), gamma =113.978 (3). The asymmetric unit is made up of a single [V10O28]6- monomer, one (NH4)+, one ethylenediammonium (H2en)2+ cation, and two H2O molecules. Supramolecular interactions such as N-H...O and O-H...O hydrogen bonds build the three-dimensional network, ensuring the connection between organic cations, water molecules, and the inorganic framework. The Fourier Transform Infrared result shows distinct bands associated with decavanadate moieties, organic molecules, water molecules and ammonia and it was correlated with the crystal structure. The organic moieties, water molecules, and ammonium ions are all lost during the hybrid compound's thermal decomposition. The study of the corrosion inhibiting behavior of the decavanadate solution clearly showed a much stronger effect in acidic media than in a neutral environment. However, the biological activity of (NH4)2(H2en)2{V10O28}.4H2O revealed humble results.