Ionic Radii in Mixed-Valence and Nonstoichiometric Metal Oxides and Their Polymorphic Forms

Abstract  A linear dependence of was found for ionic radii on the cube root of molecular volume standardised per oxygen atom (M _a/b O) of MO oxides of alkali earth metals, M₂O oxides of alkali metals and MO₂ oxides of f-electron metals, and parameters of the linear equation were calculated. This equation makes it possible to predict mean ionic radii of metals in compact structures of polymorphic forms of oxides, mixed-valence oxides and oxides showing deviation from stoichiometry, otherwise not accessible. Index Abstract  It is possible to predict mean ionic radii of metals in compact structures of polymorphic forms of oxides, mixed-valence oxides and oxides showing deviation from stoichiometry, otherwise not accessible, knowing the molecular volume standardised per oxygen atom of (M _a/b O) of MO oxides of alkali earth metals, M₂O oxides of alkali metals and MO₂ oxides of f-electron metals. Fig. The relation between the cube root of the molecular volume of oxides and the radii of the respective metal ions.      

Solid State Synthesis and Hierarchical Supramolecular Self-assembly of Organic Salt Cocrystals

Abstract This paper describes the solid-state synthesis and systematic studies of versatile supramolecular self-assembly of 14 new series of organic salt cocrystals. Hierarchical self-assembly in the solid state utilizes the cooperative interaction of hydrogen bonding, electrostatic and π–π interactions. These salts are crystallized as a highly ordered self-assembly directed by intermolecular non-covalent interaction. Index Abstract Fourteen cocrystals of organic salt have been characterized by single crystal X-ray diffraction and their solid-state packing pattern has been compared. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

Synthesis and Crystal Structure of a New Binuclear Samarium Complex with Salicylate

Index Abstract  In the dinuclear compound (HPhen)₂[Sm₂(Hsal)₈(H₂O)₂] · 2H₂O (Hsal = o-HOC₆H₄CO₂ ⁻, Phen = 1,10-phenanthroline), intermolecular hydrogen bonds and π–π stacking interactions between parallel aromatic rings result in the formation of a two-dimensional supramolecular network.      

A Unusual Bridging Mode of Diphenylhydantoin in Pentaaquabis[(5,5-Diphenylhydantoinato)Potassium]

Abstract  A new complex of diphenylhydantoin, pentaaquabis[(5,5-diphenylhydantoinato)potassium], has been synthesized and the structure has been solved by X-ray diffraction. The crystals are monoclinic, space group C2/c, with a = 34.959(5) ?, b = 8.273(4) ?, c = 11.692(2) ?, β = 109.069(13)°, M _r = 670.80, V = 3196.0(17) ?³, Z = 4 and R = 0.050. The potassium cations are assembled in dimers bridged through the carbonyl O atoms of the anions. The metal atom is in a distorted octahedral coordination environment. Index Abstract  In pentaaquabis[(5,5-diphenylhydantoinato)potassium] the potassium cations are coupled in dimers through the carbonyl O atoms of the anions.      

Using of Taguchi Method for Experimental Design of Crystallization Processes of an Oxidant: Tetraethylammonium Chlorochromate (VI)

Abstract  Crystallization of tetraethylammonium chlorochromate (C₂H₅)₄N[CrO₃Cl], TEACC, with desirable particle size as a performance characteristic was used to illustrate the design procedure. Taguchi design of experiments (DOE) method has been used for to plan a minimum number of experiments and optimization of crystallization processes. Four factors, which influence the crystal size, crystal growth and nucleation, were chosen. These factors are concentration, temperature, type of solvent and method of crystallization. After optimization the results show that concentration is most effective factor that has largest percent of contribution 53.26% and type of solvent is least effective factor that has smallest percent of contribution 4.33%. The optimum conditions are vapor diffusion as method, 0.043 g/15 mL for concentration, 0 °C for temperature and acetonitrile as solvent. These conditions must be produced suitable crystals for single crystal X-ray diffraction experiment. These results confirmed by experimental data and the crystals of the optimum conditions found to have suitable properties for single crystal X-ray diffraction. These crystals had sent for single crystal X-ray diffraction and diffraction data gathered successfully. A red block crystal was mounted on a glass fiber. The X-ray data determined monoclinic system, space group C2(#5), with a = 12.023(3), b = 7.998(2), c = 14.527(4) ?, β = 114.187(4)°, V = 1274.4(6) ?³ and Z = 4. Index Abstract  The Taguchi design of experiments (DOE) method has been used for to plan a minimum number of experiments and optimization of crystallization processes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and Crystal Structures of Three Pyrazine-2-carboxylate Containing Isostructural Complexes: M(2-pyrazine-carboxylate)<Subscript>3</Subscript> (M = Co<Superscript>+3</Superscript>, Cr<Superscript>+3</Superscript>, and Rh<Superscript>+3</Superscript>)

Abstract Three new isostructural coordination complexes, M(pca)₃, where M = Co (1), Cr (2), or Rh (3) and 2-pyrazine-carboxylate (pca), have been synthesized solvothermally and characterized by single crystal X-ray diffraction and powder X-ray diffraction. In structures 1-3, the pca ligand chelates to the metal centers in a tris-chelating arrangement through proximal nitrogen and oxygen donor atoms. Structures 1-3 are monoclinic and crystallize in the space group C2/C. In structure 1, a = 28.066(13) ?, b = 8.036(4) ?, c = 13.577(6) ?, and β = 90.2(10)°. In structure 2 a = 28.318(3) ?, b = 8.089(4) ?, c = 13.792(12) ?, and β = 90.256(2)°. In structure 3, a = 28.679(4) ?, b = 8.051(13) ?, c=13.847(2) ?, and β = 90.585(2)°. Graphical Abstract Three new isostructural coordination complexes, M(pca)₃, where M = Co, Cr, or Rh and 2-pyrazine-carboxylate (pca), have been synthesized solvothermally and characterized by single crystal X-ray diffraction and powder X-ray diffraction.      

Synthesis of 7,4′-Bis-(hydroxyl)-8,3′,5′-tris-(hydroxymethyl)isoflavone and Crystal Structure of its Ester

Abstract 7,4′-bis-(hydroxyl)-8,3′,5′-tris-(hydroxymethyl)isoflavone (I) and its ester were synthesized and examined by IR, element analysis and ¹H NMR. The crystal of 7,4′-bis-(acetyl oxide)-8,3′,5′-tris-(acetoxymethyl)isoflavone (II) was studied by X-ray diffraction. (II) crystallizes in the monoclinic with space group P2 ₁ /c. a = 17.987(3) ?, b = 17.972(3) ?, c = 8.4087(11) ?, β = 97.703(3)°, V = 2693.7(6) ?³ and Z = 4. The molecular structure of the ester consists of a benzopyranone moiety, a phenyl moiety, two acetyl oxides and three acetoxymethyl groups. Hydrogen bonds and aromatic stacking interactions link the ester into a two-dimensional structure. Index Abstract 7,4′-bis-(hydroxyl)-8,3′,5′-tris-(hydroxymethyl)isoflavone and its ester were synthesized and examined by IR, element analysis and ¹H NMR. The result of the ester’s crystal structure showed that hydrogen bonding and aromatic π–π stacking assemble the ester into a two-dimensional networking structure.      

The Crystal Structures of Bis(2-amino-5-methylpyridinium) Tetrabromometallate(II): Intermolecular Interactions in (C<Subscript>6</Subscript>H<Subscript>9</Subscript>N<Subscript>2</Subscript>)<Subscript>2</Subscript>[MBr<Subscript>4</Subscript>]; M = Cd and Co

Abstract The crystallization and structures of a triclinic (henceforth T) (C₆H₉N₂)₂[CdBr₄] and a monoclinic (henceforth M) of (C₆H₉N₂)₂[CoBr₄] are reported. The crystal packing of both solids is analyzed and compared: both contain parallel chains of cations and stacks of anions. In both T and M, each [MBr₄]²⁻ is hydrogen bonded non-symmetrically to surrounding cations in a ladder chains that run along b axis, with planar cations in both structures falling in parallel to the planes to anions. In T the cation chains are further involved in classical π···π stacking, while in M the cation chains show less significant stacking, with longer repeat distance. Index Abstract Extensive N–H···Br hydrogen bonds link both anions and cations into chains of the ladder type parallel to the crystallographic b axis. The crystal structures of bis(2-amino-5-methylpyridinium) tetrabromometallate(II): Intermolecular interactions in (C6H9N2)2[MBr4]; M = Cd and Co Rawhi Al-Far and Basem Fares Ali      

Structural Report for Sc[(R,R)-norephedrine-pybox](OTf)3 Dimeric Complex

Abstract The title compound containing two metal centers each complexes to one enantiopure chiral norephedrine-derived pyridyl-(bis) oxazoline (pybox) ligand and linked by two hydroxide bridges, crystallizes to give rodlike form in the space group P2₁(# 4). Cell Parameters are a = 10.2344(18) ?, b = 13.952(3) ?, c = 23.371(4) ?, β = 94.586(4)°, V = 3326.6(10) ?³. The metal-hydroxide motif forms a square plane at the center of the structure with the scandium centers exhibiting a distorted pentagonal bipyramid coordination sphere consisting of the chelating ligand and two additional triflouromethyl sulfonyloxy species positioned anti to each other. Graphical abstract The complex contains two metal centers each complexes to one enantiopure chiral norephedrine-derived pyridyl-(bis) oxazoline (pybox) ligand and linked by two hydroxide bridges. Structural report for Sc[(R,R)-norephedrine-pybox](OTf)₃ dimeric complex Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and Structure of the Dimeric Copper(II) Complex Tetrakis[<Emphasis Type="Italic">N</Emphasis>-thiazol-2-yl-(4-methylphenyl)sulfonamidate]dicopper(II)

Abstract The coordination chemistry of the ligand N-thiazol-2-yl-toluenesulfonamidate towards the copper(II) ion has been investigated using an electrochemical synthesis method. The X-ray structure of this complex was elucidated and is discussed. The compound crystallised in the monoclinic crystal system, P2₁/c space group with a = 17.3888(9), b = 16.3003(9), c = 18.3679(9) ? and β = 114.3640(10)°. Four bidentate sulfathiazolato anions bridge two metal centers in a paddle-wheel fashion, with the nitrogen atoms as donors to give a dimeric species with a Cu···Cu distance of 2.7859(5) ?. Graphical Abstract The coordination chemistry of the ligand N-thiazol-2-yl-toluenesulfonamidate towards the copper(II) ion has been investigated using an electrochemical synthesis method. The X-ray structure of the product has been elucidated and is discussed. Sulfathiazolato anions act as bridging ligands to give a dimeric species with a Cu···Cu distance of 2.7859(5) ?.      

Spectroscopic Studies and Crystal Structure of 3-[(2-morpholinoethylimino)methyl]benzene-1,2-diol

Abstract Schiff base 3-[(2-morpholinoethylimino)methyl]benzene-1,2-diol has been synthesized from the reaction of 4-(2-aminoethyl)morpholine with 2,3-dihydroxybenzaldehyde. The title compound has been characterized by elemental analysis, IR, ¹H-NMR, ¹³C-NMR and UV–visible techniques. The structure of the compound also has been examined crystallographically. For the compound exist as dominant form of enol-imines in both the solutions and solid state. The crystal structure has been solved by direct methods and refined by full-matrix least squares. The title compound crystallize in the monoclinic space group P2₁/n with a = 12.085(1), b = 8.256(1), c = 13.650(1) ?, β = 108.56(1)°, V = 1291.1(2) ?³, D _x = 1.288 g cm⁻³, respectively (R ₁ = 0.0336 and wR ₂ = 0.0922 for 2117 reflections [I > 2σ(I)]. Index abstract Intramolecular hydrogen bonding is important on the tautomeric properties and the type of aldehyde plays a vital role of the enol-imine and keto-amine properties of the Schiff base ligand.      

Molecular Structure of [Me<Subscript>2</Subscript>Al(μ-OPh)]<Subscript>2</Subscript>: A Crystallographic and Ab initio Study

Abstract The molecular structure of [Me₂Al(μ-OPh)]₂ has been determined. The phenoxide ring is parallel to the Al₂O₂ ring rather than the energetically favored perpendicular configuration determined by ab initio calculations. Ab initio calculations successfully predict the structures of sterically demanding analogs. The adoption of the parallel configuration allows for an estimation of the magnitude of crystal packing forces. A discussion of the parameters controlling the structures of dialkylaluminum phenoxides is presented. Crystal data: group Pbca, a = 12.127(2), b = 8.491(2), c = 17.299(4) ?, V = 1781.3(6) ?³, Z = 4, R = 0.0695, wR ₂ = 0.1390. Graphical Abstract The molecular structure of [Me₂Al(μ-OPh)]₂ has been determined. The phenoxide ring is parallel to the Al₂O₂ ring rather than the energetically favored perpendicular configuration as determined by ab initio calculations.      

Synthesis and Crystal Structure of Compound 1,5-bis(4-methoxyphenyl)-3a-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-3aH-benzo[b][1,2,4]oxadiazolo[4,5-d][1,4]thiazepine

Abstract The crystal structure of title compound has been determined. The compound crystallizes in the triclinic system with space group P-1, lattice parameters; a = 9.2938 (5) ?, b = 11.9992 (7) ?, c = 25.5918 (13) ?, α = 91.343 (2)°, β = 95.8360 (10)°, γ = 101.005 (2)°, V = 2784.3 (3) ?³, Z = 4, X-Ray analysis reveals that the molecular backbone consists of tricyclic system with the central seven-membered ring in twisted chair-like conformation. Graphical abstract The crystal structure of 1,5-bis(4-methoxyphenyl)-3a-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-3aH-benzo[b][1,2,4]oxadiazolo[4,5-d][1,4]thiazepine was first determined by single-crystal X-ray diffraction which reveals that the molecular backbone consists of a tricyclic system with the central seven-membered ring in twisted chair-like conformation .     

Synthesis and Crystal Structure of 3-[(Naphthalen-2-yl)methyl]Isocoumarin

Abstract 3-[(Naphthalen-2-yl) methyl]isocoumarin was synthesized by the reaction of homophthalic acid with 2-(naphthalen-2-yl)acetyl chloride at elevated temperature and its crystal structure has been determined (C₂₀H₁₄O₂), Mr = 286.31, a = 13.704(3), b = 7.356(4), c = 7.042(7) ?, β = 99.21(3)°, space group Pc, Z = 2, and V = 700.7(8) ?³. The isocoumarin and the naphthalene ring systems are individually planar and the dihedral angle between the mean planes of these two ring systems is 70.05(8)°. Graphical Abstract Synthesis and crystal structure of 3-[(Naphthalen-2-yl)methyl]isocoumarin Aamer Saeed, Junmei Liang, Masood Parvez The synthesis and crystal structure of a novel isocoumarin, 3-[(naphthalen-2-yl)methyl]isocoumarin has been presented.      

<Emphasis Type="Italic">Trans-</Emphasis>dichlorodioxobis(triphenylphosphate)molybdenum(VI), MoO<Subscript>2</Subscript>Cl<Subscript>2</Subscript>[OP(OPh)<Subscript>3</Subscript>]<Subscript>2</Subscript>

Abstract  The molecular structure of trans-dichlorodioxobis(triphenylphosphate) molybdenum(VI), MoO₂Cl₂[OP(OPh)₃]₂ has been determined. Crystal data: Monoclinic, Pn, a = 11.767(2), b = 10.341(2), c = 15.682(3) ?, β = 92.27(3)°, V = 1906.8(7) ?⁻³, Z = 2. Trans-dichlorodioxobis(triphenylphosphate)molybdenum(VI) was obtained by the reaction of molybdenum oxide, HCl and triphenylphosphate and was characterized by elemental analysis, IR, and ¹H-NMR spectroscopy. Index Abstract   Trans-dichlorodioxobis(triphenylphosphate)molybdenum(VI), MoO₂Cl₂[OP(OPh)₃]₂ V. Huch¹, R. Kumar², S. Mathur¹, R. Ratnani² The immediate environment around Mo is distorted octahedral with two cis-oxygen atoms and two trans-chlorine atoms along with two triphenylphosphate moieties.      

Synthesis, Structure and Properties of (H2NCH2CH2NH3)3 {(VO)6 [B10O16 (OH)6]2} · 11H2O

Abstract A new polyoxovanadoborate cluster (H₂NCH₂CH₂NH₃)₃ {(VO)₆[B₁₀O₁₆(OH)₆]₂} · 11H₂O was prepared by hydrothermal technique and characterized by single crystal X-ray diffraction analysis, IR and TGA. The crystal of the new compound belongs to monoclinic system, space group C2/c with a = 20.198(1) ?, b = 13.4476(8) ?, c = 21.602(1) ?, β = 97.067(1)°, V = 5822.8(5) ?³, Z = 4, D _c = 1.956 g cm⁻³, M = 1714.4, μ = 1.066 mm⁻¹, S = 1.905, R = 0.059, R _w = 0.0966. Index Abstract A new polyoxovanadoborate cluster (H2NCH2CH2NH3)3{(VO)6 [B10O16(OH)6]2} · 11H2O was prepared by hydrothermal technique and characterized by single crystal X-ray diffraction analysis, IR and TGA.      

Dimer Formation in 4-Benzyl-5-Methoxymethyl-3-Methyl-1<Emphasis Type="Italic">H</Emphasis>-Pyrrole-2-Carboxylic Acid Benzyl Ester

Abstract A new substituted pyrrole, a precursor of meso-free-porphyrins, has been synthesised and characterised by single-crystal X-ray diffraction: monoclinic, P2₁/c with a = 14.607(9) ?, b = 5.136(2) ?, c = 25.832(17) ?, β = 108.14(5)°, Mr = 349.41, V = 1841.6(18) ?³, Z = 4. The molecules are assembled in centrosymmetric dimers via strong N–H...O hydrogen bonds. The dimers are gathered into chains via C–H...π intermolecular interactions. Graphical abstract The molecules in 4-benzyl-5-methoxymethyl-3-methyl-1H-pyrrole-2-carboxylic acid benzyl ester are joined in dimmers by strong hydrogen bonds. The dimmers are aggregated in chains running along the b axis through C-H...?€ intermoleculear interactions. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and Crystal Structure of La(NO<Subscript>2</Subscript>)(SO<Subscript>4</Subscript>)(H<Subscript>2</Subscript>O)

Abstract Single crystals of new open-framework lanthanide sulphate nitrite La(NO₂)(SO₄)(H₂O) has been synthesized, in the presence of 2,6-diformyl-4-chlorophenol. His structure has been determined by X-ray diffraction data: the complex crystallizes in the tetragonal system, space group P4₃, with a = 7.0028(2) (?), b = 7.0028(2) (?), c = 11.8341(4) ?, V = 580.34(3) ?³, Z = 4, D _c = 3.582 Mg m⁻³. The three-dimensional (3D) framework of this compound is built up by the linkages of lanthanide atoms and the oxygen atoms of the sulphate and nitrite groups. The lanthanum atom is 9-fold coordinated. The structure is unfamiliar in lanthanide chemistry and this compound represents the first example of nitrite lanthanide sulphate complex. Graphical Abstract An unfamiliar structure in lanthanide chemistry represented by the first example of nitrite lanthanide sulphate complex is described.      

Octahedral Copper(II) Carboxylates with 1,10-Phenanthroline: Synthesis,Structural Characterization,DNA-Binding and Anti-Fungal Properties

Two mono-nuclear axially distorted octahedral copper(II) complexes have been prepared and characterized via FT-IR, UV–Visible, elctrochemical, electron spin resonance and powder and single crystal XRD techniques. The complexes consist of a phenanthroline and two carboxylate ligands each bonded in bidentate fashion. Carboxylates are ortho-nitro-2-phenyl acetate (L1) and para-chloro-2-phenyl acetate (L2). Structural study showed that both complexes possess Jahn–Teller distorted octahedral geometry. The bulk purity was assessed from the matching experimental and simulated powder XRD spectra. The results of spectroscopic techniques are consistent with each other. ESR data revealed single electron occupancy of d_x² ? _y² orbital with ²B_1g as ground state typical of tetragonally distorted octahedral geometry. Electrochemical solution study showed diffusion controlled electron transfer processes with diffusion co-efficient values of 10.323?×?10^–8 cm²s^–1 and 0.972?×?10^–8 cm²s^–1 for 1 and 2. Complexes exhibited excellent DNA-binding activity studied via UV–Visible spectroscopy, cyclic voltammetry, florescence spectroscopy and viscometry yielding K_b values of 1.871?×?10⁴ M^–1 (1) and 1.577?×?10⁴ M^–1 (2), 0.38?×?10⁴ M^–1 (1) and 6.39?×?10⁴ M^–1 (2) and 2.1?×?10⁶ M^–1 (1) and 2.0?×?0⁶ M^–1 (2), respectively, for the first three techniques. Complexes possess good antifungal activity against three fungal strains.

Graphic Abstract

     

Propeller-like Conformation of Diphenylacetic Acid

Abstract Crystal structure of diphenylacetic acid has been solved by X-ray diffraction. The crystals are monoclinic, space group P2₁/c, with a = 12.254(4) ?, b = 7.2260(8) ?, c = 17.521(4) ?, β = 133.38(1)°, Mr = 212.24, V = 1127.6(5) ?³, Z = 4 and R = 0.045. A strong hydrogen bond links the molecules in dimers. The dimers are connected by weaker C–H···π and π···π interactions. A calculation was performed for the isolated molecule and for the dimer within the Hartree-Fock (HF) level with a 6-311G(d) basis set. In both calculations, the minimum of the energy is achieved with the phenyl rings assuming a more symmetric arrangement around the central carboxylic plane than is experimentally observed. Graphical Abstract In diphenylacetic acid the molecules are coupled in dimers by a strong hydrogen bonds. Weaker intermolecular interactions involving the aromatic ring π systems join the dimers together. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.