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], [Na(CHNO)(HO)] (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, [Na(CHNO)(CHOH)(HO)] (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 (Na2NO and Na3NO in 1, and NaNO/NaNO for both atoms in 2 due to solvent disorder), while two other sodium ions maintain the NaNO 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.

Halide-bridged polymers are a type of coordination polymer whereby halide ligands act as bridging ligands between the metal centres. The crystal structures of three halide-bibridged polymers of the formula [Hg(μ-X)(4-Etpy)], namely, catena-poly[[(4-ethylpyridine)mercury(II)]-di-μ-halido], obtained through the combination of the organic ligand 4-ethylpyridine (4-Etpy, CHN) and HgX (X = Cl, Br or I), were determined. In these structures, abbreviated as 4epHgCl, 4epHgBr and 4epHgI, respectively, the Hg ion exhibits a coordination number of five. All three structures were found to display a similar one-dimensional scalloped polymeric chain with halide ligands bridging pairs of Hg ions in a bidentate fashion; however, 4epHgI differs from the other two structures in terms of the packing arrangement of the polymer. The change of the halide ligand to the larger iodide ligand disrupts the formation of the regular halide-bibridged polymeric chain observed in the chloride and bromide analogues, with 4epHgI displaying pseudo-bridging in the polymer chain.

The crystal structure of the novel Knoevenagel-type indole derivative (2E)-2-(1H-indol-3-ylmethylidene)-4,4-dimethyl-3-oxopentanenitrile, CHNO, was determined by single-crystal X-ray diffraction and further characterized by NMR, FT-IR and UV-Vis spectroscopy. The compound crystallizes in the monoclinic space group P2/c (Z = 4). The molecule has a nearly planar conformation across the indole ring and the adjacent C=C-C[triple-bond]N fragment. In the crystal, molecules are linked by N-H...O hydrogen bonds into chains parallel to the b axis, which are reinforced by inversion-related π-π stacking interactions in a slipped configuration along the a axis; additional C[triple-bond]N...H contacts further stabilize the supramolecular framework. Hirshfeld surface analysis reveals that H...H and H...C contacts dominate the packing, with smaller contributions from H...N and H...O interactions. Pairwise interaction energy calculations highlight the key role of π-π stacking (E = -46.8 kJ mol) and N-H...O hydrogen-bonded chains (E = -43.6 kJ mol), with dispersion identified as the principal stabilizing force.

Deprotonation of the Schiff base 2,6-dimethyl-N-(1-phenylethylidene)aniline, CHN or [MeC(Ph)=N(2,6-MeCH)], 1, with one equivalent of lithium diisopropylamide (LDA) and subsequent reaction with half an equivalent of SiPhCl gave a new diimine, N-[2-({2-[(2,6-dimethylphenyl)imino]-2-phenylethyl}diphenylsilyl)-1-phenylethylidene]-2,6-dimethylaniline, CHNSi, 2. Further treatment of 2 with LDA in the presence of tetrahydrofuran (THF) yielded the target binuclear ansa-bis(1-azaallyl) lithium compound {μ-N-[2-({2-[(2,6-dimethylphenyl)azanidyl]-2-phenylethyl}diphenylsilyl)-1-phenylethylidene]-2,6-dimethylanilinido}bis[(tetrahydrofuran)lithium], [Li(CHNSi)(CHO)], 3. Both 2 and 3 were characterized by H and C NMR spectroscopy and elemental analysis, and the structures of 1, 2 and 3 were confirmed by X-ray crystallography. Density functional theory (DFT) calculations were carried out for compounds 1-3. In addition, the catalytic properties of 3 towards the ring-opening polymerization of ϵ-caprolactone were investigated and the compound showed good catalytic activity.

The structural chemistry of selenourea ligands is quite diverse, though examples of their coordination to cobalt are rare. In this study, the solid-state structures of the selenourea 1,3-diethylimidazole-2-selone, CHNSe, and the cobalt complexes dichloridobis(1,3-diethylimidazole-2-selone-κSe)cobalt(II), [CoCl(CHNSe)] (1), and dichloridobis(1,3-diisopropylimidazole-2-selone-κSe)cobalt(II), [CoCl(CHNSe)] (2), are presented. Two crystallization methods for the coordination complexes are utilized. The structures of complexes 1 and 2 are compared with the few existing examples in the literature, revealing a similar trend for terminal binding modes, rather than bridging modes which are often seen for late d-block metal complexes. Density functional theory calculations reveal a trend in cobalt-selenium bond strengths for 1,3-dialkyl-substituted imidazole-2-selones of Me ≃ Et < Pr.

Our laboratory recently explored a highly stereospecific rearrangement of epoxides into tetrahydrofurans. To unambiguously determine the stereochemical outcome of this rearrangement, single crystals of one of the products, (2R*,3R*)-2-(2-phenoxyethyl)tetrahydrofuran-3-yl acetate, CHO, were grown and analyzed. Based on the crystal structure data, we were able to show that the contiguous stereocenters of this molecule are in a syn configuration, and we now suggest with confidence a plausible mechanism for the rearrangement reaction. The syn configuration of the ring may also account for the inability of most members of this class to crystallize, as it imparts a kink in the structure reminiscent of low-melting unsaturated fatty acids.

Recrystallization of pazufloxacinium mesylate from HCl solutions yielded two previously unknown salts of pazufloxacin. These were characterized by X-ray diffraction and are bis(oxidanium) pentakis[(2S)-6-(1-azaniumylcyclopropyl)-7-fluoro-2-methyl-10-oxo-4-oxa-1-azatricyclo[7.3.1.0]trideca-5(13),6,8,11-tetraene-11-carboxylic acid] heptachloride decahydrate, 2HO·5CHFNO·7Cl·10HO (1), and (2S)-6-(1-azaniumylcyclopropyl)-7-fluoro-2-methyl-10-oxo-4-oxa-1-azatricyclo[7.3.1.0]trideca-5(13),6,8,11-tetraene-11-carboxylic acid chloride ethanol hemisolvate 1.75-hydrate, CHFNO·Cl·0.5CHO·1.75HO (2), which were obtained from acetonitrile and ethanol, respectively. The compounds crystallize in the noncentrosymmetric triclinic space group P1. Salt 1 contains five independent cations and seven chloride anions, while compound 2 contains eight independent cations and anions. In both, an intramolecular COOH...O=C hydrogen bond is present and the amino group is protonated. The cations, anions and solvent molecules form extensive hydrogen-bonded frameworks. In addition, in both structures, the cations are packed into infinite stacks via π-π interactions, with interplanar distances of approximately 3.2 Å.

The structures of three doubly-acylated 4-aminoantipyrine (AP) compounds where the aryl substituent is varied are reported and analysed in terms of their relative conformation, intermolecular interactions and overall packing; these are N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-methyl-N-[(4-methylphenyl)carbonyl]benzamide, CHNO, N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-N-[(furan-2-yl)carbonyl]furan-2-carboxamide, CHNO, and N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-N-[(thiophen-2-yl)carbonyl]thiophene-2-carboxamide, CHNOS. The compounds were crystallized using the encapsulated nanodroplet crystallization (ENaCt) protocol. Where previous singly-acylated AP compounds produced structures with obvious classical hydrogen-bonding motifs, the doubly-acylated derivatives lack classical donors and therefore exhibit weak C-H hydrogen bonds and interactions involving the π-system. All three AP compounds form bifurcated C-H...O interactions having either dimer or chain motifs, with the other structure-directing interactions being dependant on the nature of the aryl substituent.

The molecular structures of two novel cobalt aminodiphosphine (PNP) complexes (1 and 2) are reported, namely, bis[bis(diphenylphosphanyl)(pentyl)amine-κP,P']chloridocobalt(III) di-μ-chlorido-bis[dichloridocobalt(II)], [CoCl(CHNP)][CoCl], and bis[bis(diphenylphosphanyl)(propan-2-yl)amine-κP,P']chloridocobalt(III) di-μ-chlorido-bis[dichloridocobalt(II)], [CoCl(CHNP)][CoCl], featuring variation in the N-atom substituent, i.e. n-pentyl in complex 1 and isopropyl in complex 2. The asymmetric unit of complex 1 contains a five-coordinated cationic [CoCl{κ-P,P-(N)-CH}] species and a [Co(μ-Cl)Cl] anion, while complex 2 includes a five-coordinated cation [CoCl{κ-P,P-(N)-CH}], half a [Co(μ-Cl)Cl] anion, and disordered diethyl ether and dichloromethane solvent molecules. The impact of ligand-induced strain, particularly due to the small bite angles of the PNP aminodiphosphine ligands, was examined in the context of geometric constraints and their influence on stability and reactivity. A Cambridge Structural Database (CSD) survey, along with a noncovalent interaction (NCI) analysis of the analogous [TMCl(PNP)] (where TM = transition metal and n = 1 or 2) core, revealed an inverse correlation between P-TM-P bite angles and N...TM contact distances. This correlation is attributed to the influence of the van der Waals radius of the metal: smaller metals allow wider bite angles and stronger N...TM contacts, whereas larger metals favour narrower bite angles and longer N...TM distances. NCI analysis indicated significant steric repulsion at the TM...N contacts, reflecting strain imposed by ligand geometry. A comparison of sign(λ)ρ eigenvalues suggests that Mo-P bonds exhibit weaker attractive interactions relative to Co-P and Ru-P bonds, with Cr-P bonds being the weakest. These findings provide pointers to structural and electronic factors governing coordination in PNP-ligated transition-metal complexes, offering rational design and catalytic and material applications.

Two benzamide-based derivatives were synthesized and their structures solved for the first time. The successful syntheses of N-ethyl-4-iodobenzamide (CHINO, NE4IBA) and N-ethyl-4-ethynylbenzamide (CHNO, NE4EBA) were achieved via a simple synthetic route. The molecules of NE4IBA in the crystal form one-dimensional double chains with strong hydrogen bonding and weak I...I halogen interactions, while NE4EBA forms two-dimensional hydrogen-bonded layers, including acetylene moieties engaging in C-H...O interactions within a rigid planar layer packing arrangement. Intermolecular N-H...O interactions between the amide groups dominate in both crystal structures. The strong exothermal effect of acetylene-group polymerization was detected immediately after melting NE4EBA using a simultaneous thermal analysis.

In the presence of 4-[4-(1H-imidazol-1-yl)phenyl]pyridine (ipp), the self-assembly reaction of 2-methoxyterephthalic acid (Hmta) with Co ions produced the complex poly[[{μ-4-[4-(1H-imidazol-1-yl)phenyl]pyridine}(μ-2-methoxyterephthalato)cobalt(II)] monohydrate], {[Co(CHO)(CHN)]·HO} or {[Co(mta)(ipp)]·HO} (denoted as HU29). The complex was structurally characterized by thermogravimetric analysis, elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Single-crystal structure analysis revealed that the mta anions and ipp ligands are connected according to AABB and ABAB modes to form four distinct helical chains. These helical chains further construct a three-dimensional (3D) framework. Owing to the similar geometries of mta and ipp, combined with the low coordination numbers of the Co centres, the resulting 3D framework exhibits a fivefold interpenetrating structure. Topological analysis indicates that HU29 can be simplified as a four-connected dia net. UV-Vis absorption spectroscopy shows a broad absorption band in the UV-Vis region and a band gap of 2.72 eV based on the Kubelka-Munk method, indicating semiconductor behaviour. Moreover, a magnetic study reveals that antiferromagnetic interactions occur in HU29 between 300 and 2 K.

With the aim of producing an extended bridging ligand for the assembly of coordination polymers, a terphenyl ligand incorporating carboxyl and phenol functionalities, namely, 4''-hydroxy-1,1':4',1''-terphenyl-4-carboxylic acid (Hhtpa, CHO, 1), was prepared. Within the structure, complementary hydrogen bonding between carboxylic acid groups leads to dimer formation with additional hydrogen bonding between phenolic groups, resulting in the formation of a 2D network. Following the addition of NaCO, mono- and dianionic forms of the ligand are generated within a compound of composition Na(Hhtpa)(htpa)·hydrate or {[Na(CHO)(HO)](CHO)} (2). The addition of tetraethylammonium hydroxide (NEtOH) solution to the acid leads to the formation of (EtN)Hhtpa·2(dioxane) or CHN·CHO·2CHO (3) and (EtN)(Hhtpa)(Hhtpa)·hydrate or 5CHN·[H(CHO)]·2CHO·17.522HO (4), with hydrogen-bonded chains a feature of both. Compound 4 contains both the Hhtpa anion, and pairs of htpa dianions linked by a single proton between phenolate O atoms to generate a trianionic unit, [H(htpa)]. A ladder-shaped anionic coordination polymer of composition (NEt)[Zn(htpa)Cl] or {(CHN)[Zn(CHO)Cl]} (5) was obtained when Zn was combined with htpa in the presence of NEt and chloride. Finally, an anionic coordination polymer with the formulation (EtN)[Zn(htpa)(OAc)]·1.5(dioxane) or {(CHN)[Zn(CHO)(CHO)]·1.5CHO}} (6) was generated with both OAc (acetate) and htpa serving as bridging ligands between Zn centres in a 2D network.

The crystal structure of bis[μ-3,5-bis(pyridin-2-yl)pyrazolato-κN,N:N,N]bis[bis(methanol-κO)cobalt(II)] dinitrate methanol disolvate, [Co(CHN)(CHO)](NO)·2CHO (I), was solved by X-ray diffractometry in order to gain insights into its electronic and catalytic properties because of its relevance to an analogous cobalt(II) dimer (V) which was shown to be highly active for CO reduction. The geometrical and electronic properties are also discussed in relation to other reported Co dimers having analogous structures (compounds II-IV and VI). Interestingly, I was found to possess quite similar structural features compared with the five other reported analogues (II-VI). The similarly elongated coordinate bond lengths in I-VI further implied a consistency in their spin states at the metal centres. By analogy to a report on V, all these compounds were suggested to possess a high-spin septet state (S = 3), previously evidenced for V by measuring its magnetic susceptibility data. The validity of these considerations was also confirmed by examining the density functional theory (DFT)-based structures, together with the energies of three possible spin states (S = 3, 1 and 0).

Four new crystal structures of the salts of N-[(2,3-dimethylphenoxy)alkyl]aminoalkanol derivatives with anticonvulsant activity are reported. Bis{D,L-trans-N-[(2,3-dimethylphenoxy)ethyl]-1-hydroxycyclohexan-2-aminium} succinate, 2CHNO·CHO, 1, and its polymorph 1p, crystallize in the monoclinic space group P2/n, 1 with two cations and one anion, and 1p with four cations and two anions in the asymmetric unit. The other two salts, D,L-trans-N-[(2,3-dimethylphenoxy)ethyl]-1-hydroxycyclohexan-2-aminium 6-carboxypyridine-2-carboxylate, CHNO·CHO, 2, and N-[(2,3-dimethylphenoxy)propyl]-3-hydroxypiperidinium pyridine-2-carboxylate, CHNO·CHO, 3, crystallize in the monoclinic space group P2/c, with one cation and one anion in each asymmetric unit. The geometry of the created polymorphs indicates the main differences in the conformation of the linker between the two rings. The arrangement of the ether O atom and the N atom shows an unusual antiperiplanar conformation for the cations of 1p. The crystal packing of all four salts is dominated by charge-assisted hydrogen bonding between the protonated N atom and the carboxylate group of the corresponding acid. Structural studies have been enriched by quantum chemical calculations.

Hirshfeld atom refinement (HAR) has so far been explored almost exclusively for the determination of accurate and precise H-atom positions from X-ray diffraction experiments, neglecting other features of the resulting crystal structures and molecular wavefunctions. In contrast, here we compare the applicability of the HAR and transferable aspherical atom model (TAAM) approaches for the structure refinement, as well as for the reconstruction of electron-density distribution in a series of quinoic compounds, known for their pronounced single-double bond alternation. A set of five quinone-like compounds has been crystallized and investigated using single-crystal X-ray diffraction at standard resolution and subjected to various structure refinement approaches, namely, 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione (Cl4Q), CClO, 2,3,5,6-tetrafluorocyclohexa-2,5-diene-1,4-dione (F4Q), CFO, 2-[4-(dicyanomethylidene)cyclohexa-2,5-dien-1-ylidene]propanedinitrile (TCNQ), CHN, 2-[4-(dicyanomethylidene)-2,5-difluorocyclohexa-2,5-dien-1-ylidene]propanedinitrile (F2TCNQ), CHFN, and 2-[4-(dicyanomethylidene)-2,3,5,6-tetrafluorocyclohexa-2,5-dien-1-ylidene]propanedinitrile (F4TCNQ), CFN. The HAR results quantitatively reproduce the alternating electron-density effects in the studied compounds, while the electron densities from the TAAM approach, utilizing pseudoatom parameters averaged over a large number of chemical compounds, do not perform as well in capturing bond alternation. As a consequence of the differences in the electron-density models, the two refinement approaches also yield distinct atomic displacement parameters (ADPs).

The crystal structure of the metastable form of S-ibuprofen-nicotinamide cocrystals, CHO·CHNO, was solved from powder X-ray diffraction. This form was obtained by melting a molar mixture of S-ibuprofen and nicotinamide at 100 °C, and then cooling. The high-resolution powder X-ray diffraction pattern of this new phase was recorded at room temperature using synchrotron radiation at SOLEIL Synchrotron (France). A hypothetical structure was obtained from the Monte-Carlo simulated annealing method and confirmed by Rietveld refinement. The symmetry is monoclinic (space group P2, No. 4) and the unit cell contains four molecules, two of nicotinamide and two of S-ibuprofen. Density functional theory (DFT) energy minimization simulation was performed in order to locate the H atoms. The determination of the crystallographic structure of this metastable form allowed an explanation of the main mechanisms at the origin of the relative stability of the two forms of the S-ibuprofen-nicotinamide cocrystals. This also made it possible to explain the transition mechanism between the two forms with temperature.

The ternary boride MgNiB (magnesium dinickel hexaboride) crystallizes as a new representative of the CeCrB structure type. The Mg and Ni atoms occupy sites with mmm and mm2 symmetry, respectively. The B atoms occupy two sites with m.. and m2m symmetry. The 14-membered polyhedron around the Mg atom is a hexagonal prism, with two adjacent lateral faces centred by Mg atoms. The Ni atoms are encapsulated in 10-vertex polyhedra. The trigonal prismatic coordination is typical for both B atoms. The electronic structure was calculated by the tight-binding linear muffin-tin orbital atomic spheres approximation (TB-LMTO-ASA) method. The electron concentration is higher around the B atoms, which form eight-membered channels along b, which are filled with Mg and Ni atoms. The maximum hydrogen absorption is up to 2.38 wt% H.

Salcaprozate sodium (SNAC) is a clinically approved oral permeation enhancer, notably used in the formulation of oral semaglutide. Despite its pharmaceutical importance, the crystallographic information of SNAC or its free acid form, salcaprozoic acid {systematic name: 8-[(2-hydroxyphenyl)formamido]octanoic acid, CHNO, denoted HNAC}, has not been reported previously. Here, we present the first crystallographic and physicochemical characterization of HNAC using single-crystal X-ray diffraction and complementary analytical techniques. The structure reveals the molecular conformation, hydrogen-bonding network and packing features of HNAC, supported by a complementary solid-state dataset. These findings provide fundamental insights into the structural and physicochemical properties of this physiologically relevant form of SNAC.

Dissymmetric ligands have garnered interest due to their ability to simultaneously coordinate to multiple different acceptors. Herein, we report the synthesis of a dissymmetric thioether N,N'-bidentate ligand, namely, 2-[(6-chloropyrimidin-4-yl)sulfanyl]pyrimidine-4,6-diamine (CHClNS, L1), along with its hydrated form (CHClNS·HO). In addition, we describe the structure of a nitrate salt of the protonated ligand {4,6-diamino-2-[(6-chloropyrimidin-4-yl)sulfanyl]pyrimidin-1-ium nitrate, CHClNS·NO} and a cobalt(II) complex of L1 (dichlorido{2-[(6-chloropyrimidin-4-yl-κN)sulfanyl]pyrimidine-4,6-diamine-κN}cobalt(II), [CoCl(CHClNS)]). The structures of all four compounds were determined by single-crystal X-ray diffraction and Hirshfeld surface analyses were performed. These analyses reveal unengaged hydrogen-bond donors and acceptors in both the neutral ligand and its water solvate, while protonation or metal coordination induces a conformational change that enables full engagement of hydrogen-bond donors. These structural insights have implications for the molecular design of ligands in ion-sensing applications.

The structure of the 1:1 gallic acid (3,4,5-trihydroxybenzoic acid)-N-methylurea cocrystal, CHO·CHNO, (I), has been determined by single-crystal X-ray diffraction. In the crystal, molecules of both components form O-H...O and N-H...O hydrogen-bonded complexes. These complexes are further linked by O-H...O, N-H...O and C-H...O hydrogen bonds, together with aromatic π-π stacking interactions, to generate a triperiodic supramolecular network. Energy framework analysis shows that electrostatic contributions predominate over dispersive ones in (I). Quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses indicate that the O-H...O and N-H...O interactions are strong, with homonuclear hydrogen bonds being stronger than heteronuclear ones. Stabilization of the carboxylic acid-urea complexes arises primarily from charge transfer resulting from orbital interactions between the lone electron pairs of hydrogen-bond acceptors (O atoms) and the empty antibonding orbitals of the hydrogen-bond donor [LP(O) → BD*(D-H)].