Pharmaceutical Salts of Fluoroquinolone Antibacterial Drugs with Acesulfame Sweetener

Novel organic salts of norfloxacin and ciprofloxacin with artificial sweeteners such as saccharin and acesulfame were prepared. The two salts 1 and 2 were characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Finally, the crystal structures were solved by single crystal X-ray diffraction data and the structures were analyzed in terms of supramolecular synthons. In norfloxacin acesulfamate 1, two norfloxacin cations and two acesulfame anions form an eight membered cyclic tetramer supramolecular synthon. The salt, ciprofloxacin acesulfamate 2, has a similar structure as salt 1. This study contributes the importance of crystal engineering and supramolecular chemistry to the pharmaceutical applications in terms of interactions and structural correlations in the design of new solid phases.

Supplemental materials are available for this article. Go to the publisher's online edition of Molecular Crystals and Liquid Crystals to view the free supplemental file.     

Synthesis and Crystal Structures of (E)-1-Phenyl-3-[(2,4,6-Trimethylphenyl)]prop-2-En-1-One and (E)-1-Phenyl-3-[(4-Trifluoromethylphenyl)]prop-2-En-1-One

Two chalcone compounds, namely (E)-1-phenyl-3-[(2,4,6-trimethylphenyl)]prop-2-en-1-one (1) and (E)-1-phenyl-3-[(4-trifluoromethylphenyl)]prop-2-en-1-one (2), have been synthesized and structurally characterized by elemental analysis, ¹H NMR spectrum, and single-crystal X-ray diffraction analysis. The chalcone molecules in (1) and (2) have the common skeleton of 1,3-diaryl-2-propen-1-one and adopt an (E)-configuration about the C = C double bonds. In addition, X-ray analysis reveals that the π···π stacking interactions are well observed in the crystal structure of (1) and (2).     

Synthesis,crystal structure,thermal behavior and luminescence property of a cobalt(II) complex of pyridine-2,6-dicarboxylic acid containing benzimidazole as auxiliary ligand

The new cobalt(II) complex [Co(pydca)(bim)₃] (1) (where H₂pydca = pyridine-2,6-dicarboxylic, bim = benzimidazole) has been synthesized and characterized by elemental analysis, Infrared spectroscopy, X-ray single crystal analysis, thermogravimetric and fluorescent analysis. Single crystal X-ray diffraction analysis reveals that the mononuclear complexes are linked by N–H…O hydrogen bonds. Fluorescent analysis reveals that complex 1 exhibits intense luminescence in ethanol solution at room temperature.     

Polymorphic single crystal ? single crystal transition in K0.975Rb0.025NO3

Polymorphic transformations in K_0.975Rb_0.025NO₃ single crystals have been investigated by optical microscopy and X-ray diffraction. The equilibrium temperature between modifications II and III has been determined. It is established that the crystal growth at II ↔ III polymorphic transitions is accompanied by the formation and growth of daughter-modification nuclei in the matrix crystal.     

α-Diimine Chelation at a Triosmium Cluster: Synthesis and X-ray Structure of 1,1-Os<Subscript>3</Subscript>(CO)<Subscript>9</Subscript>(μ-CO)(1,10-phen)

Abstract The α-diimine ligand 1,10-phenanthroline (phen) reacts with the activated cluster 1,2-Os₃(CO)₁₀(MeCN)₂ to afford the carbonyl-bridged cluster 1,1-Os₃(CO)₉(μ-CO)(phen), which has been characterized by IR and NMR spectroscopies and X-ray diffraction analysis. Replacement of the 1,5-cyclooctadiene (cod) ligand in 1,1-Os₃(CO)₁₀(cod) by phen proceeds sluggishly over a 24 h period, showing less than 5% conversion to 1,1-Os₃(CO)₉(μ-CO)(phen). Graphical abstract α-Diimine Chelation at a Triosmium Cluster: Synthesis and X-ray Structure of 1,1-Os ₃ (CO) ₉ (μ-CO)(1,10-phen) Bhaskar Poola, Xiaoping Wang, and Michael G. Richmond The reaction between the triosmium cluster 1,2-Os3(CO)10(MeCN)2 and 1,10-phenanthroline yields 1,1-Os3(CO)9(μ-CO)(phen) at room temperature. The presence of a bridging carbonyl group in the product cluster has been observed by IR spectroscopy and confirmed by X-ray crystallography.      

Structure and spectroscopic properties of borane-1-trimethylsilylpiperidine

As a new borane source for hydroboration, borane-1-trimethylsilylpiperidine (1) was synthesized from the reaction of diborane with 1-trimethylsilylpiperidine. The molecular structure of 1 was unambiguously determined by a combination of ¹H, ¹³C, and ¹¹B NMR spectra and X-ray single crystal analysis. X-ray crystallographic data for 1: Orthorhombic Pnma (#62), a = 6.4476(6) Å, b = 10.503(1) Å, c = 6.058(2) Å, V = 1087.4(2) ų, Z = 4.     

Adsorption and Electronic Properties in Tetramethylbenzidine-Intercalated Tetrasilicicfluormica

Abstract

Adsorption and electronic properties in tetramethylbenzidine-intercalated tetrasilicicfluormica were investigated by powder X-ray diffraction, ESR, TG, and DC-electric conductivity measurements.     

Two d10 Coordination Complexes Based on the Substitutional Aromatic Multicarboxylate and N-Donor Co-Ligands: Syntheses,Structures, and Properties

Two new coordination complexes, formulated as [Cd₂(3-NPA)(phen)₄(H₂O)₂]₂ (1) and [Zn(3-NPA)(phen)(H₂O)]_n (2) (3-NPAH₂ = 3-nitrophthalic acid, phen = 1,10-phenanthroline) have been synthesized by hydrothermal reactions of the rigid neutral ligand phen with metal ions in the presence of 3-NPAH. X-ray analysis shows that complex 1 is a 0D dinuclear structure that is arranged to form a 3D supramolecular framework through hydrogen bonds and π–π stacking interactions. In polymer 2, the 3-NPA^2? anions coordinate the Cd(II) ions in a tridentate mode to form a 1D infinite chain structure, which is connected by the hydrogen bonds and π–π stacking interactions resulting in a 3D supramolecular architecture. In addition, the two complexes were characterized by infrared spectroscopy, elemental analysis, luminescent properties, thermo gravimetric analysis, and powder X-ray diffraction (PXRD).     

Synthesis and Structure of a New Coordination Polymer [Cd(pzdc)(bpy)]<Subscript>n</Subscript> (H<Subscript>2</Subscript>pzdc = Pyrazine-2,3-dicarboxylic Acid,bpy = 2,2′-Bipyridine)

Abstract A new 3D coordination polymer, [Cd(pzdc)(bpy)]_n (1) (pzdc = pyrazine-2,3-dicarboxylic acid, bpy = 2,2′-bipyridine), has been hydrothermally synthesized and characterized by the elemental analyses, IR spectrum and single crystal X-ray diffraction. X-ray diffraction analysis reveals that 1 (C₁₆H₁₀CdN₄O₄) crystallizes in monoclinic space group P2₁/c, features an interesting 3D zipper-like networks constructed by 2D layers via strong π–π packing interactions. Cell unit parameter for 1: a = 9.767(1), b = 14.022(2), c = 13.719(2) ?, β = 100.86(1)^o, and Z = 4. Graphical Abstract A new 3D coordination polymer, [Cd(pzdc)(bpy)]_n (pzdc = pyrazine-2,3-dicarboxylic acid, bpy = 2,2′-bipyridine), has been hydrothermally synthesized and characterized by the elemental analyses, IR spectrum and single crystal X-ray diffraction. X-ray diffraction analysis reveals that [Cd(pzdc)(bpy)]_n features an interesting 3D zipper-like networks constructed by 2D layers via strong π–π packing interactions.      

Ag(I) and Cu(II) Coordination Polymers of Pyridylmethyl-Benzimidazole Ligand: Syntheses,Crystal Structure,and Influence of Metal Ion

In our efforts to investigate the relationships between the metal ions and the structures of their complexes based on N-donor ligand, 1-(4-pyridylmethyl)-1H-benzimidazole (L), and their complexes [Ag(L)(ClO₄)]_n (1),{[Cu(L)₂ (ClO₄)₂](H₂O)₂}_n (2) were synthesized and structurally characterized by elemental analyses, IR spectra and single-crystal X-ray diffraction analysis. Structural analyses show that 1 possess one-dimensional (1D) double helix chain structure, which further forms two-dimensional supramolecular framework connected by Ag···Ag and Ag···O weak interactions. When the metal ion was changed to Cu(II), 2 was obtained, which shows a two-fold interpenetrating three-dimensional diamond network. The results show that the metal ions and weak interactions play important roles in the construction of such coordination architectures. X-ray powder diffractions show that the bulk synthesized materials and the crystals used for diffraction are homogeneous. Meanwhile, the photoluminescent property of the complex 1 is investigated in the solid state at room temperature.     

Crystal Structures of Two-Dimensional Coordination Polymer Fe(Methylpyridine)2Ni(CN)4

Abstract

Two-dimensional coordination polymer compounds FeL₂Ni(CN)₄ (L: 2, 3, or 4-methylpyridine) have been synthesized and characterized by single crystal X-ray diffraction method.     

Syntheses,Structural, and Biological Studies of Two New Peptide Compounds, 2(s)-(5-fluorouracil-1-aceto)amino-2-isopropyl Acetate Hemihydrate and 2(s)-(5-fluorouracil-1-aceto)amino-2-isopropyl Acetic Acid

Abstract  Two new peptide compounds, 2(s)-(5-fluorouracil-1-aceto)amino-2-isopropyl acetate hemihydrate (1:1/2H ₂ O) and 2(s)-(5-fluorouracil-1-aceto)amino-2-isopropyl acetic acid (2), have been synthesized and characterized by elemental analysis, IR, ¹H- and ¹³C NMR spectroscopy. Two new compounds were structurally characterized by single-crystal X-ray diffraction. The thermal stabilities of compounds 1:1/2H ₂ O and 2 were studied by DSC-TGA techniques. The result of the biological test showed that the compounds 1:1/2H ₂ O and 2 have certain antitumor activities. Index Abstract  Two new peptide compounds, 2(s)-(5-fluorouracil-1-aceto)amino-2-isopropyl acetate hemihydrate (1:1/2H2O) and 2(s)-(5-fluorouracil-1-aceto)amino-2-isopropyl acetic acid (2), have been synthesized and characterized by elemental analysis, IR, 1H-, and 13C NMR spectroscopy. Two new compounds were structurally characterized by single-crystal X-ray diffraction. The thermal stabilities of compounds 1:1/2H2O and 2 were studied by DSC-TGA techniques. The result of the biological test showed that the compounds 1:1/2H2O and 2 have certain antitumor activities.      

1,3,2,5-Dioxadiphosphorinanes. Six-membered ring compounds containing two different phosphorus atoms

The reaction of bis(hydroxymethyl)phenylphosphane withtert-butyldichlorophosphane leads to the formation ofcis-2-tert-butyl-5-phenyl-1,3,2,5-dioxadiphosphorinane (1). Thecis configuration was definitively proven by the X-ray diffraction study of the 2, 5-dithioxo derivative (2), which was obtained from (1) by a stereoselective reaction. The diselenoxo compound (3) was also prepared. These three new compounds were subjected to a complete NMR study (¹H,¹³C,³¹P, and⁷⁷Se).     

Photooxygenation of 2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene

The photooxygenation of 2-amino-3-cyano-4,5,6,7-tetrahydro-benzo[b]thiopene1 was carried out in the presence of thiourea in order to reductively trap the intermediate; however, the rearranged compound 3-cyano-7-hydroxy-2-thio-2,4,5,6,7,7a-hexahydroindole2 was isolated. The structure, determined by X-ray crystallography, is described, and the mechanism for the formation of2 is discussed.     

Construction of Three Novel Coordination Complexes by 3-Nitrophthalic Acid Plus N-Donor Ligands: Synthesis,Structure, and Properties

In order to explore new coordination frameworks with novel designed 3-nitrophthalic acid and N–donor ancillary ligands, three novel coordination complexes, namely, [Co₂(3-NPA)₂(2,2′-bipy)₂(H₂O)₂]?2H₂O (1), [Mn₂(3-NPA)₂(4,4′-bipy)₃(H₂O)₆]?(4,4′-bipy) (2), and [Pb₂O(3-NPA)]_n (3) (where 3-NPAH₂ = 3-nitrophthalic acid, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been hydrothermally synthesized. X-ray structure analysis reveals that 1 and 2 are dinuclear structures, while 3 is a two-dimensional (2D) network polymer. And the hydrogen bonds and π–π stacking also play important roles in affecting the final structure where complexes 1-2 have 3D and 2D supramolecular architectures, respectively. These complexes have been characterized by powder X-ray diffractions (PXRD) and thermal gravimetric analyses (TGA). In addition, their photochemical properties have also been investigated.     

Crystal Structure of Diethyl[(4chlorophenyl)(dibenzylamino)methyl]propanedioate

Abstract  

The titled new functionalized N,O,O-ligand of type diethyl[(4-chlorophenyl)(dibenzylamino)methyl]propanedioate (4) is prepared in good yield through condensation of dibenzylamine, with 2-arylidene-malonic acid diethyl esters 3. The structure of 4 was determined by spectral (IR, ¹H NMR), elemental analyses and X-ray diffraction data. The molecular conformation shows two possible pockets ready to coordinate two metal atoms.     

Linear trinuclear mixed valance MnIII-MnII-MnIII complex: Synthesis,crystal structure and characterization

A new linear trinuclear Mn^III-Mn^II-Mn^III complex 1 has been synthesized and characterized by elemental, spectral, X-ray and magnetic analysis. X-ray diffraction studies show that the central Mn^II ion is located at a crystallographic inversion center and is triply bridged to the terminal Mn^III ions through one methoxide, one syn-syn carboxylate and one hydroxyl oxygen bridges with the short Mn^III…Mn^II distance that is 3.047 Å. The intermolecular C-H…O, C-H…π and ring-metal interactions are observed in the hydrogen-bonded assembly of 1. Magnetic studies reveal that the mixed-valence complex 1 has S = 3/2 ground state with antiferromagnetic exchange interactions between Mn^II and Mn^III ions.     

Microstructure of Milled Mesophase Pitch-Based Carbon Fibers as an Anode Material for Li-ion Batteries

Abstract

The microstructure of milled mesophase pitch-based carbon fibers (mMPCFs) that have been developed as an anode material for Li ion batteries have been studied as a function of heat treatment temperature (HTT), by SEM, X-ray diffraction, and Raman spectroscopy. And the results obtained are compared with those by X-ray diffraction (XRD) and SEM observations, for the characterization of specific structural features of mMPCFs as a promising anode material.     

Pyridine-2,6-Dicarboxylic Acid (Dipic): Crystal Structure from Co-Crystal to a Mixed Ligand Nickel(II) Complex

Abstract  

Pyridine-2,6-dicarboxylic acid (dipic) was used for the synthesis of a co-crystal with 1,10-phenanthroline-5,6-dione (phen-dione) and a nickel(II) complex. The co-crystal dipic·phen-dione·4H₂O (1) has been synthesized and studied by X-ray crystallography. The structure is stabilized with hydrogen bonds between dipic, H₂O and phen-dione. It is surprising that there is no direct hydrogen bonding between phen-dione and dipic and yet the molecules co-crystallize in aqueous solution. A new complex of nickel(II), [Ni(phen)(dipic)(H₂O)]·4H₂O (2), (where phen = 1,10-phenanthroline) has been synthesized and characterized by elemental and thermogravimetric analyses, FT-IR, UV–Vis and ¹H-NMR spectroscopy. The structure of (2) has been studied by X-ray crystallography. The coordination around Ni(II) is a distorted octahedron. The crystal packing shows that the dimensionality of (2) is enlarged to 3D, through hydrogen bonds and π–π interactions. Cyclic voltammetry of (2) shows that the Ni(II/I) couple is irreversible.     

Syntheses, Structures, Fluorescence and Magnetic Property of Two Complexes with the Asymmetric dpa Ligand

Abstract  

Two compounds [Zn(Hdpa)₂(2,2′-bipy)]₂ (1) and [Mn(dpa)(4,4′-bipy)] _n (2) (H₂dpa=2,2′-biphenyldicarboxylate, bipy=dipyridine) are synthesized by hydrothermal reactions and structurally characterized by Single crystal X-ray diffraction analyses. Compound 1 is a dual-core molecular structure of two Zn ions in the same coordination environment, we studied the fluorescence of compound 1. Compound 2 is a layer structure based on the one-dimensional chains bridged by 4,4-bipy, it displays weak antiferromagnetic interactions between the inter-chain Mn²⁺ ions.