Synthesis, structure, and activity evaluation of two silver(I) complexes as Helicobacter pylori urease inhibitors

Two silver(I) compounds, [Ag(R,R-hxn)](C₇H₄BrO₂) · 2H₂O (I) (Chxn = 1,2-diaminocyclohexane) and [Ag(C₅H₆N₂)₂]₂(C₈H₄O₄) · 10H₂O (II), were synthesized and complex I was structurally characterized by X-ray crystallography. Compound I contains a catena-(trans-1,2-diaminocyclohexane) silver polycation ([Ag(Chxn)]_∞) in a roughly linear fashion, while II possesses a linear-type silver monocation. Compounds I and II were evaluated for their inhibitory activities against Helicobacter pylori urease in vitro. Both were found to have strong inhibitory activities against H. pylori urease comparable to that of acetohydroxamic acid.     

Adduct formation of cadmium(II) N,N-cyclo-hexamethylenedithiocarbamate, [Cd2{S2CN(CH2)6}4], with morpholine: Synthesis, molecular structure, and thermal behavior of a crystalline adduct cis-[Cd{NH(CH2)4O}2{S2CN(CH2)6}2]

The reaction of [Cd₂{S₂CN(CH₂)₆}₄] (I) with morpholine gives a crystalline adduct of cadmium N,N-cyclo-hexamethylenedithiocarbamate [Cd{NH(CH₂)₄O}₂{S₂CN(CH₂)₆}₂] (II), whose coordination sphere includes two molecules of the donor base. The structural organization and thermal behavior of II is studied by X-ray diffraction analysis and simultaneous thermal analysis in comparison with the original binuclear cadmium complex I. The central cadmium atom (coordination number 6) coordinates two morpholine molecules and two structurally equivalent S,S’-anisobidentate ligands HmDtc to form a chromophore [CdN₂S₄] with the structure of a distorted octahedron. The thermal destruction of II proceeds in two stages and includes consecutive steps of dissociation of the Cd-N bonds followed by the desorption of morpholine and thermolysis of the dithiocarbamate moiety of the adduct to form CdS as the final product. The structure of binuclear [Cd₂{S₂CN(CH₂)₆}₄] is refined for a correct refinement of the geometric characteristics of compounds I and II.     

Polymerization of ethylene by SiO2-supported two-component catalytic systems containing bis(imino)pyridine and bis(imine) ligands

The polymerization of ethylene initiated by SiO₂-supported two-component catalytic systems based on 2,6-bis[1-(2,4-dimethyl-6-cyclohexylphenylimino)ethyl]pyridine iron (II) chloride (I) and 1,2-bis(2-cyclohexyl-4,6-dimethylphenylimino)acenaphthene] nickel bromide (II) was studied. Methylaluminoxane was used as a cocatalyst during support. It was shown that the activity of two-component catalytic systems and the molecular mass and short-chain branching of polyethylene samples depend on the supporting procedure: simultaneous immobilization of components I and II, separate immobilization of components on the support (first I, then II, and vice versa), and the use of a mixture of components I and II immobilized separately on SiO₂.     

Xanthate complexes of {Nb2S4}4+

Alkyl xanthate complexes [Nb₂S₄(S₂COR)₄] (R = Et (I), iso-Pr (II), n-Bu (III), and iso-Am (IV)) are synthesized by the ligand exchange reaction in solutions from (Et₄N)₄[Nb₂S₄(NCS)₈] and the corresponding potassium salts in satisfactory yields. The X-ray diffraction analyses are carried out for the isopropyl xanthate (II) and butyl xanthate (III) complexes. From the view point of mutual arrangement of chelate cycles, complexes II and III exist in crystals as ΛΔ isomers. The niobium-niobium distances are 2.8789(4) Å in complex II and 2.8856(3) Å in complex III. The first example for the formation of short S...S contacts between the disulfide ligands of the {Nb₂S₄}⁴⁺ fragments in the crystal structure of III is found (3.146 Å).     

Syntheses and crystal structures of (18-crown-6)bis(perchlorato-O,O′)strontium and (18-crown-6)bis(perchlorato-O,O′)barium

Two complexes, namely, (18-crown-6)bis(perchlorato-O,O′)strontium (I) and (18-crown-6)bis(perchlorato-O,O′)barium (II), are synthesized. Their crystal structures are determined by X-ray diffraction analysis. The structures of I (space group P2₁/c, a = 15.266 Å, b = 11.080 Å, c = 13.235 Å, β = 109.20°, Z = 4) and II (space group P2₁/n, a = 8.330 Å, b = 11.202 Å, c = 11.752 Å, β = 98.38°, Z = 2) are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.077 (I) and 0.041 (II) against 3714 (I) and 2478 (II) independent reflections (CAD-4 diffractometer, λMoK _α radiation). Complex molecules [Sr(18C6)(ClO₄)₂] in the structure of I and [Ba(18C6)(ClO₄)₂] in II (in the inversion center)—are of the host-guest type. The Sr²⁺ or Ba²⁺ cation is localized in the center of a cavity of the 18-crown-6 ligand and coordinated by its all six O atoms. In compounds I and II, the coordination polyhedron of the Sr²⁺ and Ba²⁺ cations (coordination number 10) can be described as a distorted hexagonal bipyramid with two bifurcated vertices at two O atoms of two ClO ₄ ^? ligands, which are disordered in I and II and each of them has two orientations.     

Crystal structures of nitrato-{4-bromo-2-[(2-hydroxyethylimion)methyl]phenolo}-(3,5-Dibromopyridine)copper and nitrato-{2,4-dibromo-6-[(2-hydroxyethylimino)methyl]phenolo}-(3,5-dibromopyridine)copper

The crystal structures of nitrato-{4-bromo-2-[2-hydroxyethylimino)methyl]phenolo}-(3,5-dibromopyridine)copper (I) and nitrato-{2,4-dibromo-6-[(2-hydroxyethylimino)methyl]phenolo}-(3,5-dibromopyridine)copper (II) are determined. The crystals of compound I are orthorhombic: a = 14.157(3) Å, b = 15.420(3) Å, c = 17.494(4) Å, space group Pbca, Z = 8, R = 0.067. The crystals of compound II are monoclinic: a = 10.675 Å, b = 13.973 Å, c = 14.007 Å, β = 111.92°, space group P2₁/n, Z = 4, R = 0.0464. In the structures of compounds I and II, the copper atom coordinates, correspondingly, singly deprotonated 4-bromo-2-[(2-hydroxyethylimino)methyl]phenol and 2,4-dibromo-6-[(2-hydroxyethylimino)methyl]phenol molecules, and 3,5-dibromopyridine, and the nitrate ion. The coordination polyhedron of the copper ion in complexes I and II is a slightly distorted tetragonal pyramid. The bases of the pyramids are formed by the imine and pyridine nitrogen atoms and the phenolic and alcoholic oxygen atoms, and the axial vertices are occupied by the oxygen atoms of the monodentate nitrato groups. In the complexes under study, the six-membered metallocycles have asymmetric gauche conformation. In crystal, complexes I are united, due to the slip plane a, through bifurcate hydrogen bonds into infinite chains along the direction [100]. Complexes II in crystal form two-dimensional networks by means of hydrogen bonds.     

Synthesis, crystal structures, and properties of inorganic-organic hybrid complexes constructed from copper(II) macrocyclic fragment

Reaction of a macrocyclic copper(II) complex [Cu(L)](ClO₄)₂ · 3H₂O (I) (L = 1,3,10,12,16,19-hexaazatetracyclotetracosane) with a hexapod carboxylate ligand H₆TTHA (H₆TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid) and a tripod carboxylate ligand H₃TATB (H₃TATB = 4,4′,4″-S-triazine-2,4,6-triyl-tribenzoic acid) yielded two mononuclear copper(II) complexes [Cu(L)][H₄TTHA] · 4H₂O (II) and [Cu(L)][HTATB] · 4H₂O (III). The complexes I–III have been structurally characterized. The crystal structures of complexes II and III show the copper(II) ion has a distorted pentacoordinate square-pyramidal geometry with two secondary and two tertiary amines from the macrocyclic complex [Cu(L)]²⁺ and one oxygen atom from the carboxylate ligand group at the axial position. The UV-Vis spectra are utilized to discuss the hydrolysis of the complex II.     

Synthesis and crystal and molecular structures of new copper and zinc complexes with aza-14-crown-4 ether having di(α-pyridyl)-substituted bispidine subunit

The complexes [Cu(L)(H₂O)](ClO₄)₂ · 2H₂O (I) and [Zn(L)Cl₂] · C₂H₅OH (II), where L is the macrocyclic substituted aza-14-crown-4 ether molecule containing di(α-pyridyl)bispidine insert, were synthesized and studied by X-ray diffraction. The Cu atoms in complex I and the Zn atoms in complex II have equal coordination numbers of 5 and different highly distorted polyhedra (the CuN₄O tetragonal pyramid and ZnN₃Cl₂ trigonal bipyramid). Ligand L in structure I performs the tetradentate tetrachelate (4N) structural function and in II, it performs the tridentate bis-chelate (3N) function. The key difference between the structures of complexes I and II is determined by different conformations of both the aza-macrocycles and bispidine substituents of ligand L.     

Isomorphous crystal structures of 4,7,13,16,21,24-hexaoxo-1,10-diaziniabicyclo[8.8.8]·hexacosane bis(tribromide) and bis(bromoiodide)

Two compounds, 7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(tribromide) and bis(bromodiiodide) — [H₂(Crypt-222)]²⁺·2Br ₃ ^? (I) and [H₂(Crypt-222)]²⁺·1.45(BrI₂)^?·0.4(Br₂I)^?·0.15 I ₃ ^? (II) — are prepared and characterized by single crystal XRD; the refinement of the second compound was more accurate. Isomorphous monoclinic structures (I, space group C2/c, Z = 4, a = 12.090, b = 15.833 Å, c = 15.732 Å, β = 95.83°; II, a = 12.548 Å, b = 16.417 Å, c = 15.748 Å, β = 94.53°) are solved by a direct method and refined in the anisotropic full-matrix approximation to R = 0.057 (I) and 0.044 (II) using all 2635 (I) and 2852 (II) measured independent reflections (automated CAD-4 diffractometer, λMoK _α). In the structures of I and II one of the trihalide anions sits at the inversion center i(000), and the second trihalide anion and the dication [H₂(Crypt-222)]²⁺ are situated at crystallographic axis 2. In the structure of II iodine is located in the center of trihalide anions, while the terminal atoms are disordered and are represented by a statistical combination of iodine and bromine atoms.     

Synthesis and structural properties of thiapyridinophane and its complex with Ni(II) and Ag(I)

The 2,11-dithia[3.3](3,5)pyrdinophane (L¹) has been synthesized by a new method and characterized by ¹H NMR, which is used to form coordination complexes C₁₄H₁₄N₄O₆S₂Ni (I) by addition of Ni²⁺ cation and C₁₄H₁₄N₃O₃S₂Ag (II) by addition of Ag⁺ cation. 2,11,20-Trithia[3.3.3](3,5)pyridinophane (L²) and 2,11,20,29-tetrathia[3.3.3.3](3,5)pyridinophane (L³) have also been synthesized as by-products. Single-crystal X-ray analysis reveals that the conformation of the L¹ is syn(boat-chair), complexes I and II also adopt syn(boat-chair) (CIF files CCDC nos. 1400332 (I) and 700724 (II)). While in I, Ni(II) is coordinated with L¹ with two nitrogen and four oxygen atoms, in II, Ag(^I) is coordinated with L¹ by two nitrogen and two sulfur atoms came from four ligands. In complexes I and II, the formation of three-dimensional structure depends on π???π stacking and hydrogen bonds.     

Synthesis,spectroscopic characterization,and crystal structures of copper(I) iodide clusters of N-methylthiourea and 1,3-diazinane-2-thione

Two copper(I) iodide complexes, [Cu₄(Metu)₆I₄] (I) and [Cu₈(Diaz)₁₂I₈] (II) (Metu = N-methylthiourea; Diaz = 1,3-diazinane-2-thione), have been prepared and their structures been determined by X-ray crystallography. The crystal structures show that complex I is a tetranuclear, while II is an octanuclear cluster, both having a Cu : S ratio of 2 : 3, characteristic of metallothioneins. In I, each of the four copper atoms is coordinated to three thiourea ligands and one iodide ion in a distorted tetrahedral mode adopting admantane-like structure. In II, four types of core arrangements are observed around copper(I), which include, Cu(μ-S₂)I₂, Cu(μ-S₂)(μ-I)I, Cu(μ-S₃)I, and Cu(μ-S₃)S each having copper(I) tetrahedrally coordinated. The complexes were also characterized by IR and ¹H and ¹³C NMR spectroscopy.     

Tetraphenylantimony(V) O,O′-dialkyl dithiophosphates [Sb(C6H5)4{S2P(OR)2}] (R = s-C4H9, c-C6H11): Synthesis, structures, and 13C and 31P CP/MAS NMR spectra

Tetraphenylantimony(V) O,O′-di-sec-butyl dithiophosphate (I) and tetraphenylantimony(V) O,O′-dicyclohexyl dithiophosphate (II) [Sb(C₆H₅)₄{S₂P(OR)₂}] (R = sec-C₄H₉ or cyclo-C₆H₁₁) were obtained. Their structures and spectroscopic properties were studied by X-ray diffraction analysis and ¹³C and ³¹P CP/MAS NMR spectroscopy. The dithiophosphate (Dtph) ligands in complexes I and II were found to be coordinated in S-monodentate and S,S′-bidentate fashions, respectively (MAS NMR data). According to X-ray diffraction data, the coordination polyhedron of antimony in molecular structure I is a trigonal bipyramid with unusual monodentate coordination of the Dtph group in the axial position.     

Hydrothermal synthesis, crystal structure, and photoluminescence of Pb(II) and Mn(II) coordination polymers based on imidazo[4,5-f][1,10]phenanthroline

Two new coordination polymers, [Pb(IDPT)₂(NO₃)₂] (I) and [Mn(IDPT)(SO₄)(H₂O)₂] (II) (IDPT = imidazo[4,5-f][1,10]phenanthroline), were synthesized by hydrothermal method and characterized by elemental analysis and single-crystal X-ray diffraction technique. The results reveal that the complex I belongs to monoclinic crystal system, space group C2/c and complex II belongs to monoclinic crystal system, P2₁/c space group. The cell parameters are: a = 19.1970(13), b = 7.3875(5), c = 17.3825(12) Å, β = 100.47(10)°, V = 2424.0(3) ų, Z = 4, F(000) = 1488 for I; a = 10.9135(6), b = 7.0230(4), c = 19.7034(10) Å, β = 99.32(10)°, V = 1490.25(14) ų, Z = 4, F(000) = 828 for II. In the structure of complex I, the metal center Pb(II) is six-coordinated, displays an octahedral geometry. Each molecule is further connected with neighboring one via π-π interactions into 1D chain. In complex II, Mn(II) is six-coordinated to form a distorted octahedral geometry. Compound II displays 1D supramolecular chain formed through hydrogen bonds. Additionally, the fluorescent properties for the complexes were investigated. Complexes I and II exhibit strong photoluminescence with emission maximum at 583 and 529 nm at room temperature.     

Crystal structures and luminescence of a series of cadmium(II) complexes based on isophorone derivative containing imidazolyl

Three new complexes, [CdL₂(CH₃COO)₂(H₂O)₂] (I), CdL₂Br₂ (II), CdL₂I₂ (III), have been successfully synthesized by self-assembly of corresponding metal salts with (E)-2-(3-(4-(1H-imidazole-1-yl)styryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile (L). The structures of the complexes were determined by single crystal X-ray diffraction analysis (CIF file CCDC nos. 957831 (I), 957792 (II), 957832 (III)). In complex I, central metal is six-coordinated and the crystal packing shows a 3D supramolecular framework. Complexes II and III display the similar 2D supramolecular structures in which the central metals are four-coordination. The luminescent properties were investigated.     

The synthesis of the [Fe(Phen)3](iso-Bu2PS2)2 Complex. The crystal structures of [Fe(Phen)3](iso-Bu2PS2)2 · 5H2O and disulfan {iso-Bu2P(S)S}2

The complex [Fe(Phen)₃][iso-Bu₂PS₂)₂ (I) was synthesized and the single crystals of [Fe(Phen)₃](iso-Bu₂PS₂)₂ · 5H₂O (II) were grown. The disulfan {iso-Bu₂P(S)S}₂ (III) was isolated. Compound II consists of the complex cations [Fe(Phen)₃]²⁺, the outer-sphere anions iso-Bu₂PS ₂ ^? , and the molecules of water of crystallization. The coordination polyhedron of the Fe atom is a distorted N₆ octahedron. Complex I is diamagnetic, and thus, the full spin of the Fe²⁺ ion S = 0. The structure of III is built of the molecules containing the S-S bridge 2.061(1) Å in length.     

Urease inhibition of oxovanadium(V) complexes with hydrazone and hydroxamate ligands

Two new oxovanadium(V) complexes, [VOL¹(SHA)] (I) and [VOL²(BHA)] (II), were prepared by the reaction of [VO(Acac)₂] (Acac = acetylacetonate) with N′-(2-hydroxybenzylidene)isonicotinohydrazide (H₂L¹) and salicylhydroxamic acid (HSHA) and 4-chloro-N′-(2-hydroxy-3-methoxybenzylidene)benzohydrazide (H₂L²) and benzohydroxamic acid (HBHA), respectively, in methanol. Crystal and molecular structures of the complexes were determined by elemental analysis, infrared spectra and single crystal X-ray diffraction (CIF file CCDC nos. 978238 (I) and 978392 (II)). The V atoms are in octahedral coordination. Thermal stability and the inhibition of urease of the complexes were studied.     

New polyarylates with nonlinear T-shaped mesogenic groups and variable hinge heteroatoms

The synthesis and comparative study of mesomorphic properties of aromatic polyesters containing the nonlinear T-shaped mesogenic sequences based on 1,4-dihydroxy-2-benzoylbenzene and hinge heteroatoms—oxygen (polyester I) or sulfur (polyester II)—have been performed. Polyester II lacks liquid-crystalline properties, in contrast to the oxygen-containing analog I demonstrating the mesomorphic behavior. In the case of polyester II samples, there is a large scatter in dynamooptical characteristics estimated in dilute N-methylpyrrolidone solutions. This behavior of polyester II is apparently associated with restriction of intramolecular mobility because of interaction between valence shells of sulfur atoms giving rise to bridge S···S bonds.     

The syntheses and structures of two silver compounds based on Phdat

Based on the organic ligand 2,4-diamine-6-phenyl-1,3,5-triazine (Phdat), two Ag(I) compounds, Ag(Phdat)₂(NO₃) (I) and Ag(Phdat)₂(OAc) (II), have been synthesized and characterized by single crystal X-ray diffractions, elemental analyses, and IR spectra. Compounds I and II are mononuclear and binuclear structures, respectively, and with the help of N-H…O and N-H…N hydrogen bonds and π…π packing interactions, the 3D supramolecular networks are built up.     

New Co(III) dioximates with hexafluorophosphate ion as stimulators of the proteolytic activity of the micromycete Fusarium gibbosum CNMN FD 12

The coordination compounds [Co(DH)₂(An)₂][PF₆] (I) and [Co(NioxH)₂(Thio)₂][PF₆] · 0.5DMF · 0.5H₂O (II), where DH- and NioxH-are dimethylglyoxime and 1,2-cyclohexanedione dioxime monoanions, respectively; An is aniline; and Thio is thiourea, were synthesized. The composition and structure of the complexes were determined by elemental analysis, IR spectroscopy, and X-ray diffraction. Compounds I and II are ionic and consist of complex cations [Co(DioxH)₂(A)₂]⁺, where DioxH is the α-dioxime residue, A is neutral organic molecule (aniline or thiourea), and [PF₆]^? anions. The coordination polyhedra of the Co(III) complex cations are octahedra formed by the set of N6 donor atoms of monodeprotonated DH-residues and two An molecules (in I) or by the N₄S₂ atoms of two NioxH-anions and two Thio molecules (in II). The formation of the crystal structure of I and II is largely determined by the [PF₆]-anions in which the fluorine atoms serve as acceptors in various hydrogen bonds. The compounds were tested as stimulators of biosynthesis of extracellular proteases of the micromycete Fusarium gibbosum CNMN FD 12. The introduction of the test complexes in optimized concentrations into the nutrition medium for cultivation of the producing strain enhances the biosynthesis of acid and neutral proteases by 63.6 and 92.5%, respectively.     

Synthesis of optically active Zn(II) complexes with thiosemicarbazones of (+)-camphor (L) and (−)-carvone (L1). The crystal structures of L and [Zn(L)2Cl2]

The optically active complexes [Zn(L)₂Cl₂] (I) and [Zn(L¹)₂Cl₂] (II) (L and L¹ are thiosemicar-bazones of (+)-camphor and (?)-carvone, respectively) were obtained. The crystal structures of L and complex I were determined by X-ray diffraction. The structure of L consists of hydrogen-bonded molecules united into chains. The crystal structure of complex I is built from mononuclear molecules. The coordination polyhedron of the Zn atom is a distorted tetrahedron Cl₂S₂. The molecule L functions as a monodentate ligand. According to data from IR spectroscopy, complex II is structurally similar to complex I.