Crystallization Water Molecules Research Articles

Crystal structure of the one-dimensional coordination polymer formed by the macrocyclic [Ni(cyclam)]2+ cation and the dianion of di-phenyl-silanediylbis(4-benzoic acid).

The asymmetric unit of the title compound, catena-poly[[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ-4,4'-(di-phenyl-silanedi-yl)dibenz-o-ato-κ2 O:O'] sesquihydrate], {[Ni(C26H18O4Si)(C10H24N4)]·1.5H2O} n , consists of the halves of the centrosymmetric macrocyclic cation and the C 2-symmetric di-carboxyl-ate dianion and of the water mol-ecule of crystallization. The Ni2+ ion is coordinated by the four secondary N atoms of the macrocyclic ligand characterized by the most energetically favourable trans-III conformation and two mutually trans O atoms of the carboxyl-ate, forming a slightly tetra-gonally elongated trans-N4O2 octa-hedron. The crystals are composed of parallel polymeric chains of the macrocyclic cations linked by the anions of the acid running along the [101] direction. Each polymeric chain is bonded to four neighbouring ones via water mol-ecules providing O-H⋯O hydrogen bonds to the non-coordinated carboxyl O atoms to form a three-dimensional supra-molecular network.

Quantum Mechanical Investigation of Three-Dimensional Activity Cliffs Using the Molecules-in-Molecules Fragmentation-Based Method.

The concept of activity cliff (AC) (i.e., a small structural modification resulting in a substantial bioactivity change) is widely encountered in medicinal chemistry during compound design. Whereas the study of ACs is of high interest as it provides a wealth of opportunities for effective drug design, its practical application in the actual drug development process has been difficult because of significant computational challenges. To provide some understanding of the ACs, we have carried out a rigorous quantum-mechanical investigation of the electronic interactions of a wide range of ACs (205 cliffs formed by 261 protein-ligand complexes covering 37 different receptor types) using multilayer molecules-in-molecules (MIM) fragmentation-based methodology. The MIM methodology enables performing accurate high-level quantum mechanical (QM) calculations at a substantially lower computational cost, while allowing for a quantitative decomposition of the protein-ligand binding energy into the contributions from individual residues, solvation, and entropy. Our investigation in this study is mainly focused on whether the QM binding energy calculation can correctly identify the higher potency cliff partner for a given ligand pair having a sufficiently high activity difference. We have also analyzed the effect of including crystal water molecules as a part of the receptor as well as the impact of ligand desolvation energy on the correct identification of the more potent ligand in a cliff pair. Our analysis reveals that, in the majority of the cases, the AC prediction could be significantly improved by carefully identifying the critical crystal water molecules, whereas the contribution from the ligand desolvation also remains essential. Additionally, we have exploited the residue-specific interaction energies provided by MIM to identify the key residues and interaction hot-spots that are responsible for the experimentally observed drastic activity changes. The results show that our MIM fragmentation-based protocol provides comprehensive interaction energy profiles that can be employed to understand the distinctiveness of ligand modifications, for potential applications in structure-based drug design.

Supramolecular arrangements of novel clickable 4-substituted 3,6-bis(2′-pyridyl)pyridazine molecules

The clickable reaction between the starting 3,6-bis(2′-pyridyl)-1,2,4,5-tetrazine (bptz) with a series of terminal alkynes-containing functional biomolecules [prop-2-yn-1-ol, 4-(prop-2′-yn-1′-yl)morpholine and D-galactose] by means of an inverse electron demand Diels-Alder pathway has been studied and four new 4-substituted 3,6-bis(2′-pyridyl)pyridazine derivatives (4-Rdppn) were isolated, namely 4-(hydroxymethyl)-3,6-di(pyridin-2-yl)pyridazine (1), 4-((prop-2-yn-1-yloxy)methyl)-3,6-di(pyridin-2-yl)pyridazine (2) obtained by post-etherification reaction of 1, 4-(morpholinemethyl)-(3,6-dipyridin-2-yl)pyridazine monohydrate (3) and 3,6-di(pyridin-2-yl)-4-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxo)[4,5-b:4′,5′-d]pyran-5-yl)methoxy)methyl)pyridazine (4). The four new compounds were characterized by elemental analysis, IR spectroscopy and 1H/13C NMR and the crystal structures of 1–3 were solved by single crystal X-ray diffraction to elucidate their molecular structure. In the light of their structural knowledge, an analysis of the role of the substituent and steric effects on the crystal packing is carried out. Focusing on their dppn fragment of 1–3, an approximate s-trans/s-trans-conformation of the rings occurs as in the free dppn molecule and the bond lengths and angles agree with those reported for this molecule. π-π interactions and hydrogen bonds involving the substituents occur in 1 and 2. In addition, the water molecule of crystallization in 3 plays an important role in determining the crystal packing.

Catena-Poly[[[aqua-copper(II)]-μ-(biphenyl-2,2'-di-carboxyl-ato)-μ-[N,N'-bis-(pyridin-4-yl)urea]] 1.25-hydrate

In the title compound, {[Cu(C14H8O4)(C11H10N4O)(H2O)]·1.25H2O} n , the CuII cations are coordinated in a square-pyramidal fashion by trans carboxyl-ate O-atom donors from two diphenate (dip) ligands, trans pyridyl N-atom donors from two bis-(4-pyrid-yl)urea (bpu) ligands, and a ligated water mol-ecule in the apical position. [Cu(H2O)(dip)(bpu)] n coordination polymer layer motifs are oriented parallel to (02). These layer motifs display a standard (4,4) rectangular grid topology and stack in an AAA pattern along the a-axis direction to form the full three-dimensional crystal structure of the title compound, mediated by N-H⋯O and O-H⋯O hydrogen bonding patterns involving the water mol-ecules of crystallization.

A 2D coordination polymer assembled from a nickel(II) tetraazamacrocyclic cation and 4,4'-(dimethylsilanediyl)diphthalate(3-) linker.

The preformed nickel(II) complex of the 14-membered macrocyclic ligand 1,4,8,11-tetraazacyclotetradecane (cyclam, L), when treated with 4,4'-(dimethylsilanediyl)diphthalic acid (H4A) in a DMF/H2O mixture (4:1 v/v) under heating, leads to [Ni(L)]3(HA)2·3DMF (I·DMF). Redissolution of this compound in a DMF/H2O/MeOH mixture (4:1:30 v/v/v) with mild acidification under gentle heating results in the formation of a similar compound but containing water and methanol molecules of crystallization, [Ni(L)]3(HA)2·5H2O·2MeOH (II·H2O). At lower temperature and concentration of reactants and longer reaction time, single crystals of composition {[{Ni(L)}3(HA)2]·4CH3OH}n (II·MeOH) were isolated. Single-crystal X-ray diffraction analysis of this compound, which, according to PXRD is isostructural with II·H2O but different from I·DMF, revealed its two-dimensional (2D) polymeric structure, i.e. poly[[bis{μ3-4-[(4-carboxy-3-carboxylatophenyl)dimethylsilyl]benzene-1,2-dicarboxylato-κ3O1:O2:O3'}tris(1,4,8,11-tetraazacyclotetradecane-κ4N)trinickel(II)] methanol tetrasolvate], {[Ni3(C18H13O8Si)2(C10H24N4)3]·4CH3OH}n. It is built up of the monoprotonated tricarboxylate HA3- ligand coordinated in a monodentate manner in the axial positions of two crystallographically independent NiII cations, one of which is located on a crystallographic inversion centre. Both metal ions adopt a slightly tetragonally elongated trans-N4O2 octahedral geometry. The compound has a lamellar structure with polymeric layers oriented parallel to the (10-2) plane, which are in turn linked via hydrogen bonds involving protonated carboxylic acid groups of the ligand. Bulk compounds I·DMF and II·H2O were characterized by FT-IR and diffuse reflectance spectroscopy and thermogravimetry, which provide evidence of their structural differences.

Coordination Polymers Based on a Biphenyl Tetraphosphonate Linker: Synthesis Control and Photoluminescence.

In this work, we used the rigid tetrapodal organic linker, [1,1′-biphenyl]-3,3′,5,5′-tetrayltetrakis(phosphonic acid) (H8btp), for the preparation of two lanthanide–organic framework families of compounds: layered [Ln7(H5btp)4(H5.5btp)2(H6btp)2(H2O)12]∙23.5H2O∙MeOH [where Ln3+ = Eu3+ (1Eu) and Gd3+ (1Gd)], prepared using microwave-irradiation followed by slow evaporation; 3D [Ln4(H3btp)(H4btp)(H5btp)(H2O)8]∙3H2O [where Ln3+ = Ce3+ (2Ce), Pr3+ (2Pr), and Nd3+ (2Nd)], obtained from conventional hydro(solvo)thermal synthesis. It is shown that in this system, by carefully selecting the synthetic method and the metal centers, one can increase the dimensionality of the materials, also increasing structural robustness (particularly to the release of the various solvent molecules). Compound 1 is composed of 2D layers stacked on top of each other and maintained by weak π–π interactions, with each layer formed by discrete 1D organic cylinders stacked in a typical brick-wall-like fashion, with water molecules occupying the free space in-between cylinders. Compound 2, on the other hand, is a 3D structure with small channels filled with crystallization water molecules. A full solid-state characterization of 1 and 2 is presented (FT-IR spectroscopy, SEM microscopy, thermogravimetric studies, powder X-ray diffraction and thermodiffractometry). The photoluminescence of 1Eu was investigated.

Copper(II)–ethylenediamine linked Nb24 dimer with one dimensional chain architecture

The one-pot synthesis of one-dimensional chain polyoxoniobate based on Nb24 building block, [{Cu(en)2(H2O)2}{Cu(en)2(H2O)}2(H2en)10][{(Nb24O72H6)[Cu(en)2]2}2Cu(en)2]·72H2O (1, en = ethylenediamine), are firstly presented. Compound 1 was structurally and compositionally characterized in the solid state by single-crystal X-ray diffraction, IR、UV spectroscopy, powder X-ray diffraction, as well as thermogravimetry and elemental analyses. The results indicate that 1 comprises a dimeric polyanion [{(Nb24O72H6)[Cu(en)2]2}2Cu(en)2]26− (1a), three copper complex cations, ten di-protonated en cations and 72 crystal water molecules. In 1a, two [{Nb24O72H6}{Cu(en)2}]16− fragments are fused together by two {Cu(en)2} bridges through one terminal oxygen atom and one bridging oxygen atom from Lindqvist units on adjacent clusters to form dimeric [(Nb24O72H6){Cu(en)2}2]228− ({Cu2Nb24}2) unit. The adjacent {Cu2Nb24}2 dimeric units are further linked together by a {Cu(en)2} ligand forming a straight 1D chain. In addition, compound 1 can be used to decolor methyl blue, and the decolorization rate can reach 94.86% after 3 min under the irradiation of natural light.

Synthesis and crystal structure of a 6-chloro-nicotinate salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4'-bi-pyridine.

A 6-chloro-nicotinate (6-Clnic) salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4'-bi-pyridine (4,4'-bpy), namely, catena-poly[[[tetra-aqua-nickel(II)]-μ-4,4'-bi-pyridine-κ2 N:N'] bis-(6-chloro-nicotinate) tetra-hydrate], {[Ni(C10H8N2)(H2O)4](C6H3ClNO2)2·4H2O} n or {[Ni(4,4'-bpy)(H2O)4](6-Clnic)2·4H2O} n , (1), was prepared by the reaction of nickel(II) sulfate hepta-hydrate, 6-chloro-nicotinic acid and 4,4'-bi-pyridine in a mixture of water and ethanol. The mol-ecular structure of 1 comprises a one-dimensional polymeric {[Ni(4,4'-bpy)(H2O)4]2+} n cation, two 6-chloro-nicotinate anions and four water mol-ecules of crystallization per repeating polymeric unit. The nickel(II) ion in the polymeric cation is octa-hedrally coordinated by four water mol-ecule O atoms and by two 4,4'-bi-pyridine N atoms in the trans position. The 4,4'-bi-pyridine ligands act as bridges and, thus, connect the symmetry-related nickel(II) ions into an infinite one-dimensional polymeric chain extending along the b-axis direction. In the extended structure of 1, the polymeric chains of {[Ni(4,4'-bpy)(H2O)4]2+} n , the 6-chloro-nicotinate anions and the water mol-ecules of crystallization are assembled into an infinite three-dimensional hydrogen-bonded network via strong O-H⋯O and O-H⋯N hydrogen bonds, leading to the formation of the representative hydrogen-bonded ring motifs: tetra-meric R 2 4(8) and R 4 4(10) loops, a dimeric R 2 2(8) loop and a penta-meric R 4 5(16) loop.

Isostructural Inorganic-Organic Piperazine-1,4-diium Chlorido- and Bromidoantimonate(III) Monohydrates: Octahedral Distortions and Hydrogen Bonds.

Halogenidoantimonate(III) monohydrates of the (C4H12N2)[SbX5]·H2O (X = Cl, 1 or Br, 2) formula, crystallizing in the same monoclinic space group of P21/n, are isostructural, with an isostructurality index close to 99%. The single crystal X-ray diffraction data do not show any indication of phase transition in cooling these crystals from room temperature to 85 K. Both hybrid crystals are built up from [SbX6]3– octahedra that are joined together by a common edge forming isolated bioctahedral [Sb2X10]4– units, piperazine-1,4-diium (C4H12N2)2+ cations and water of crystallization molecules. These structural components are joined together by related but somewhat different O/N/C–H···X and N–H···O hydrogen bonded systems. The evolution of structural parameters, notably the secondary Sb–X bonds along with the associated X/Sb–Sb/X–X/Sb angles and O/N/C–H···X hydrogen bonds, as a function of ligand exchange and temperature, along with their influence on the irregularity of [SbX6]3– octahedra, was determined. The comparison of packing features and hydrogen bond parameters, additionally supported by the Hirshfeld surface analysis and data retrieved from the Cambridge Structural Database, demonstrates the hierarchy and importance of hydrogen bond interactions that influence the irregularity of single [SbX6]3– units.

Synthesis, crystal structure and biological activity of a cobalt(III) complex derived from 6,6’-(2-hydroxypropane-1,3-diyl)bis(azanediyl) bis(methylene)bis(2-bromo-4-chlorophenol)

A new dinuclear cobalt(III) complex, 2[Co2L(HL)N3]·5H2O, derived from the reduced Schiff base 6,6’-(2-hydroxypropane-1,3-diyl)bis(azanediyl)bis(methylene)bis(2-bromo-4-chlorophenol) (H3L), was synthesized and characterized by infrared and electronic spectroscopy, and single-crystal X-ray diffraction techniques. The ligand was firstly synthesized and bound to the Co(III) center. The compound contains two dinuclear [Co2L(HL)N3] complex molecules and five water molecules of crystallization. The Co atoms in the complex are in octahedral coordination. The complex shows effective antimicrobial activity.

Crystal Structure of Glycinium Dicitratoborate Monohydrate

Crystals of glycinium dicitratoborate monohydrate H3NCH2COOH[B(C6H6O7)2] · Н2О have been synthesized and selected for the first time. Their structure is determined by X-ray diffraction analysis: triclinic system, sp. gr. Р$$\bar {1}$$, and Z = 2. The crystals consist of cation–anion layers, in which all structural units (dicitratoborate anion, glycinium cation, and crystallization-water molecule) are bound firmly by numerous hydrogen bonds.

Capturing the Heptaniobate {Nb7O22}9– Anion by Covalent Bond Formation: Synthesis, Crystal Structure, and Selected Properties of {[Fe(cyclam)]3Nb7O22}· ≈ 19 H2O

The new compound {[Fe(cyclam)]3Nb7O22}· ≈ 19 H2O (I) was synthesized at room temperature reacting aqueous solutions of K8{Nb6O19}·16 H2O, Fe(NO3)3·9 H2O and cyclam (1,4,8,11‐tetraazacyclotetradecane). In the crystal structure the heptaniobate {Nb7O22}9– anion is observed which is expanded by three [Fe(cyclam)]3+ complexes, thus suppressing further condensations into larger aggregates. The complexes are solely bound to the three terminal O2– anions of the NbO6 octahedron which expands the hexaniobate {Nb6O19}8– anion to form the heptaniobate cluster. The two O atoms in the FeN4O2 octahedron are in cis position leading to a severe distortion of the cyclam ligand with one of the CH2–CH2–CH2–N–CH2–CH2 fragments being rotated by about 90°. The {[Fe(cyclam)]3Nb7O22} units are arranged to form channels which host the crystal water molecules. The crystal water molecules can be removed by thermal treatment. Storing the sample on air the pristine sample is recovered.

Synthesis, crystal structures, and antimicrobial activity of copper(II) complexes derived from N′-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide

Two mononuclear copper(II) compounds, [Cu(HL)2](ClO4)2 · (H2L)ClO4 · 3H2O (1) and [CuL2] (2), where L is the monoanionic form of N′-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide (HL), have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination. Compound 1 contains a [Cu(HL)2]2+ complex cation, a H2L+ cation, three perchlorate anions, and three water molecules of crystallization. Compound 2 contains one neutral [CuL2] complex molecule. The Cu atoms in the complexes are in octahedral coordination, with the hydrazone ligands coordinate to the Cu atoms through the pyridine N, imine N, and enolate O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

Crystal structure, spectroscopic characterization and Hirshfeld surface analysis of aqua-dichlorido-{N-[(pyridin-2-yl)methyl-idene]aniline}copper(II) monohydrate.

The reaction of N-phenyl-1-(pyridin-2-yl)methanimine with copper chloride dihydrate produced the title neutral complex, [CuCl2(C12H10N2)(H2O)]·H2O. The CuII ion is five-coordinated in a distorted square-pyramidal geometry, in which the two N atoms of the bidentate Schiff base, as well as one chloro and a water mol-ecule, form the irregular base of the pyramidal structure. Meanwhile, the apical chloride ligand inter-acts through a strong hydrogen bond with a water mol-ecule of crystallization. In the crystal, mol-ecules are arranged in pairs, forming a stacking of symmetrical cyclic dimers that inter-act in turn through strong hydrogen bonds between the chloride ligands and both the coordinated and the crystallization water mol-ecules. The mol-ecular and electronic structures of the complex were also studied in detail using EPR (continuous and pulsed), FT-IR and Raman spectroscopy, as well as magnetization measurements. Likewise, Hirshfeld surface analysis was used to investigate the inter-molecular inter-actions in the crystal packing.

Mn(II) complex of a di-2-pyridyl ketone-N(4)-substituted thiosemicarbazone: Versatile biological properties and naked-eye detection of Fe2+ and Ru3+ ions

A novel manganese(II) complex of a di-2-pyridyl ketone N(4)-phenyl thiosemicarbazone (HL) was synthesized and characterized. Single crystal X-ray diffraction studies revealed that the asymmetric unit of the triclinic unit cell contained two independent Mn(L)2 molecules together with two water molecules of crystallization and a DMF molecule. DNA binding studies of the ligand and its complex were conducted using absorption titrations, fluorescent intercalator displacement assays and viscosity measurements. Both the ligand and the complex were found to show good DNA binding abilities and actively displaced the standard intercalator ethidium bromide. In addition to the DNA binding studies, antimicrobial activities of the compounds were also determined and the complex exhibited higher antibacterial activity compared to the ligand HL. Another interesting property exhibited by the manganese complex was its colorimetric sensing, making it an excellent probe for naked-eye detection of Fe2+ and Ru3+ ions, with a visible color change from yellow to colorless. The recognition ability of the ions by the probe was quantitatively analyzed using a titration [ion]/[complex] ratio of 0–2.

N,N'-Bis(pyridin-3-ylmeth-yl)ethanedi-amide monohydrate: crystal structure, Hirshfeld surface analysis and computational study.

The mol-ecular structure of the title bis-pyridyl substituted di-amide hydrate, C14H14N4O2·H2O, features a central C2N2O2 residue (r.m.s. deviation = 0.0205 Å) linked at each end to 3-pyridyl rings through methyl-ene groups. The pyridyl rings lie to the same side of the plane, i.e. have a syn-periplanar relationship, and form dihedral angles of 59.71 (6) and 68.42 (6)° with the central plane. An almost orthogonal relationship between the pyridyl rings is indicated by the dihedral angle between them [87.86 (5)°]. Owing to an anti disposition between the carbonyl-O atoms in the core, two intra-molecular amide-N-H⋯O(carbon-yl) hydrogen bonds are formed, each closing an S(5) loop. Supra-molecular tapes are formed in the crystal via amide-N-H⋯O(carbon-yl) hydrogen bonds and ten-membered {⋯HNC2O}2 synthons. Two symmetry-related tapes are linked by a helical chain of hydrogen-bonded water mol-ecules via water-O-H⋯N(pyrid-yl) hydrogen bonds. The resulting aggregate is parallel to the b-axis direction. Links between these, via methyl-ene-C-H⋯O(water) and methyl-ene-C-H⋯π(pyrid-yl) inter-actions, give rise to a layer parallel to (10); the layers stack without directional inter-actions between them. The analysis of the Hirshfeld surfaces point to the importance of the specified hydrogen-bonding inter-actions, and to the significant influence of the water mol-ecule of crystallization upon the mol-ecular packing. The analysis also indicates the contribution of methyl-ene-C-H⋯O(carbon-yl) and pyridyl-C-H⋯C(carbon-yl) contacts to the stability of the inter-layer region. The calculated inter-action energies are consistent with importance of significant electrostatic attractions in the crystal.

Bis{2,6-bis[(E)-(4-fluorobenzylimino)methyl]pyridine}nickel(II) dinitrate dihydrate

In the title hydrated salt, [Ni(C21H17F2N3)2](NO3)2·2H2O, the central NiII ion is coordinated by six N atoms from two tridentate chelating 2,6-bis[(E)-(4-fluorobenzylimino)methyl]pyridine ligands. While the central NiII ion is six-coordinate, its environment is distorted from an octahedral structure because of the unequal Ni—N distances. The Ni—N bond lengths vary from 1.8642 (14) to 2.2131 (15) Å, while the N—Ni—N angles range from 79.98 (6) to 104.44 (6)°. Three coordinating sites of each chelating agent are almost coplanar with respect to the pyridine ring, and two pyridine moieties are perpendicular to each other. Two non-coordinating nitrate anions within the asymmetric unit balance the charges of the central metal ion, and are linked with two crystal water molecules, forming a water–nitrate cyclic tetrameric unit [O...O = 2.813 (2) to 3.062 (2) Å]. In an isolated molecule, the fluorophenyl rings of one ligand are stacked with the central ring of the other ligand via π–π interactions, with the closest centroid-to-plane distances being 3.359 (6), 3.408 (5), 3.757 (6) and 3.659 (5) Å.

A hexaniobate expanded by six [Hg(cyclam)]2+ complexes via Hg–O bonds yields a positively charged polyoxoniobate cluster

Abstract The room temperature reaction of Hg(NO3)2 · H2O, cyclam (cyclam = 1,4,8,11-tetraazacyclotetradecane) and K8{Nb6O19} · 16 H2O in a mixture of H2O and DMSO led to crystallization of the novel compound {[Hg(cyclam)]6Nb6O19}(NO3)4 · 14 H2O, which is the first mercury containing polyoxoniobate. The structure consists of a {Nb6O19}8− cluster core which is expanded by six [Hg(cyclam)]2+ complexes via Hg–μ 2-O–Nb bond formation. The title compound contains a positively charged polyoxoniobate cluster. The crystal water molecules form small aggregates by O–H · · · O hydrogen bonding which are joined into larger aggregates by N–O · · · H–O hydrogen bonding integrating the nitrate anions.

Crystal Structure of Three Ionic Compounds of Levofloxacin

The structures of three ionic compounds of levofloxacin (LevoH or Ci18H20FN3O4) − LevoH3[CoCl4]-H2O (I), LevoH3[ZnBr4]·H2O (II), LevoH3[CuBr4]-H2O·(III) are determined. The crystals of I-III are monoclinic; in compound III, the particles are packed so that the direction of the screw axis does not coincide with the largest unit cell parameter. The asymmetric unit of the unit cell contains two LevoH32+ and CoCl42− ions and two crystallization water molecules in I; two LevoH32+ and MBr42− (M = Cu, Zn) ions and two crystallization water molecules in II and III. The absolute structure of the crystals and the configuration of the chiral center of the levofloxacinium cation S are determined. The structures are stabilized by multiple hydrogen bonds, X−Y π and π-π interactions.

Synthesis, crystal structure, vibrational study, optical properties and thermal behavior of a new hybrid material bis(3-amino-4-phenyl-1H-pyrazolium) tetrachloridocobaltate (II) monohydrate

The title organic–inorganic hybrid compound, (C9H10N3)2[CoCl4]·H2O, was synthesized by slow evaporation at room temperature. Single-crystal X-ray diffraction analysis indicates that the asymmetric unit in this compound consists of one tetrahedral geometry [CoCl4]2-, two protonated organic cations (C9H10N3)+ and one water molecule of crystallization. In the crystal structure, the inorganic layers are built from tetrachloridocobaltate anions [CoCl4]2- and free water molecules, linked together by Ow—H…Cl hydrogen bonds and halogen···halogen interactions. The organic cations are intercalated between the mineral layers via N–H⋯Cl hydrogen bonds and form chains through cycle stacking interactions. The atomic arrangement can be described as an alternation of organic and inorganic layers along the c-axis. Crystal cohesion is achieved through N–H⋯Cl, Ow—H…Cl, N–H … Ow hydrogen bonds between organic cations, inorganic anions and the water molecules building up a three-dimensional network. The vibrational properties were investigated experimentally by means of IR spectroscopy. The powder X-ray diffraction was used to confirm the phase purity. Also, The UV–visible and the photoluminescence (PL) properties of the compound were investigated at room temperature in the solid state. The crystal morphology was carried out using Bravais–Friedel–Donnay–Harker (BFDH) model. Electronic properties such as HOMO and LUMO energies were also obtained. Thermal behavior was characterized by thermogravimetric and differential scanning calorimetry TG-DSC.