8-Thiatheophylline nitrato silver (I): Spectroscopic characterization and crystal structure

A new metal-theophylline derivative was synthesized from AgNO₃ and 8-thiatheophylline. The thermal stability of the Ag(C₆H₆N₄O₂S)(NO₃) complex was studied by TG and DSC techniques. The silver coordination has been discussed from IR,¹H-NMR and¹³C-NMR spectra. The crystal structure was established by X-ray diffraction. Ag(TTH)(NO₃) crystallizes in space groupP2₁2₁2₁ witha=6.198(1),b=12.576(2),c=13.422(2) Å andZ=4. The structure was refined toR=0.032. This complex reveals interesting features in the coordination mode of the TTH ligand. The sulfur atom and the carbonyl groups are not involved in the coordination. Silver tetrahedral coordination occurs through N7 and N9 of two different TTH ligands (Ag-N7=2.422(3) Å; Ag-N9=2.356(2) Å) and through two oxygen atoms of two different nitrato groups (Ag-O=2.435(4) and 2.518(4) Å) giving a polymeric structure.     

Crystal structures of 2-pyrazinecarboxylato silver(I) and ammine 2,3-pyrazinecarboxylato disilver(I)

X-ray analysis has shown that the complexes of silver(I) with the anionic forms of 2-pyrazinecarboxylic and 2,3-pyrazinedicarboxylic acids are three-dimensional network polymers. Ag(C₅H₃O₂N₂) (1) crystallizes in space groupPna2₁ witha=7.028(2),b=11.510(3),c=6.949(2) Å andZ=4. Silver tetrahedral coordination occurs through three ligands: the first one acts as a bidentate chelator (Ag–O=2.539(4), Ag–N=2.334(4)Å), the second one involves one N pyrazine atom (Ag–N=2.196(4)Å) and the third one bonds through one O-carboxylato atom (Ag–O=2.323(4)Å). The dinuclear complex Ag₂(C₆H₂O₄N₂)(NH₃) (2) crystallizes in space groupP2₁/c witha=7.775(2),b=16.455(2),c=7.174(1) Å, -115.21(1)° andZ =4. Each of the two silver atoms shows a trigonal environment. The first silver atom involves two O carboxylic atoms (Ag–O=2.312(4), 2.374(4)Å) and one N pyrazine atom (Ag–N=2.277(3)Å) belonging to three different ligands. The second one involves one O carboxylic atom (Ag–O=2.364(3)Å) and one N pyrazine atom (Ag–N=2.304(4)Å) from the same chelating ligand and one N ammine atom (Ag–N=2.158(5)Å).     

Crystal structure of the keto-enamine form of (+) (1S,2S)-2-(2-hydroxybenzylidene)amine-1-phenyl-1,3-propanediol

The title compound crystallizes in the orthorhombic space group P2₁2₁2₁, withZ=4,a=6.068(1)Å,b=10.922(1)Å, andc=21.713(2)Å. The compound is the chiral ligand of a copper complex used as an enantioselective catalyst. It crystallizes from methanol in the keto-enamine form, though the enol-imine isomer predominates in the solution. Most N-salicylideneamines studied by X-ray are enol-imines. The two tautomeric forms may interchange through anintramolecular hydrogen bond and the distances between non-H atoms in the resulting cyclic –O–H...N=C–C=C- or –C=O...H–N–C=C- fragment may be misleading, so that H atom position is the crucial factor for determination of the proper tautomeric form.     

Crystal structure of 1-(2-hydroxyphenyl)-3-(2-thiomethoxyphenyl)-1,3-propanedione,C16H14O3S

The crystal structure of the enol tautomer of 1-(2-hydroxphenyl)-3-(2-thiomethoxyphenyl)-1,3-propanedione C₁₆H₁₄O₃S, was determined from X-ray crystallography. The finalR value was 5.99% based on 1945 unique observed reflections. The crystals are monoclinic,P2₁/c, witha=7.406(6),b=8.585(6),c=21.992(4) Å,=93.42(2),D _c =1.36 g cm^–3 forz=4. The compound is present in the solid state as a unique enol tautomer.There are two short, intramolecular OO contacts of 2.553(4) and 2.577(4) Å. Both the phenol and the enol H atoms are asymmetrically located with respect to the O atoms.     

Tri-(nitrato)-bis-(hexamethylenetetramine)-nona-(aquo) neodymium (III): Synthesis,crystal structure,IR and Raman spectroscopy

This paper reports the structural and spectroscopic properties of tri-(nitrato)-bis-(hexamethylene-tetramine)-nona-(aquo)neodymium (III). The crystals are monoclinic, space groupP2₁/n,Z=4, witha=17.902(4),b=9.335(2),c=18.489(4)Å, B=112.07(2)°. The crystal structure consists of one [Nd(NO₃)₂(H₂O)₆]⁺ cation, two NO ₃ ^– anions coordinated to the neodymium atom, two hexamethylene tetramine molecules, third free NO ₃ ^– anion and three water molecules. The structure was refined to a finalR index 0.039 and weightedR _w 0.039 for 6221 observed reflections. The IR and Raman spectra are fully consistent with the crystallographic results.     

Metal-betaine interactions. II. Crystal structures of catena-dichloro(betaine)cadmium(II) and dimeric diaquabis(betaine)tetrachlorodicadmium(II)

Two cadmium(II) complexes of betaine (BET) have been prepared and characterized by X-ray crystallography. [Cd(BET) (–Cl)₂] (1), is a one-dimensional polymer in which each cadmium atom is coordinated by two pairs of bridging chlorine atoms [Cd-Cl=2.631(2), 2.614(2) Å] and two oxygen atoms from different bridging carboxylate groups [Cd-O=2.291(6), 2.329(6) Å] in the form of a compressed octahedron. [Cd(BET)(H₂O)Cl(–Cl)]₂ (2) is a dimer with each cadmium atom in a distorted octahedral coordination environment, being surrounded by a chelating bidentate carboxylate group [2.480(2), 2.332(3) Å], one aqua ligand [2.364(3) Å], two bridging chlorine atoms [2.659(1), 2.557(1) Å], and one terminal chlorine atom [2.480(1) Å].     

Crystal and molecular structure of nickel(II) dicyanothiosemicarbazide monohydrate

The structure of the title compound (Ni(CN)₂(CH₅N₃S)·H₂O) has been determined, from X-ray diffractometer data, by the heavy-atom method and refined by least-squares. The finalR-values, based on 3109 observed reflections, areR=0.035 andR _w =0.039. The complex has square-planar geometry with two adjacent cyano carbon atoms (Ni-C, 1.838(2) Å and 1.862(2) Å)and thiosemicarbazide sulfur and nitrogen atoms (Ni-S, 2.169(1) Å and Ni-N, 1.923(2) Å). The water molecule does not enter the inner coordination sphere of the nickel atom; however, it plays a very important role in the crystal structure. Water is coordinated by hydrogen bonds to four adjacent complex units.     

Redetermination of the structure of bis[chloro-2-(2-hydroxy-4,5-dimethylphenylazo)-5,5-dimethyl-4,5,6,7-tetrahydrobenzothiazol-7-on] copper(II) complex

The crystal structure of C₁₇H₁₈ClCuN₃O₂S (M = 854.78, monoclinic, P2₁/c, a = 8.316(2), b = 18.461(4), c = 11.774(2) Å, = 99.64(3)°, V = 1782.0(7) ų, Z = 4) is formed by dimeric molecules [C₁₇H₁₈ClCuN₃O₂S]₂ with two monomeric units linked together by two chlorine atoms. The Cu atom is coordinated by two chlorine atoms, an oxygen atom, the azo nitrogen atom attached to the benzene ring, and the nitrogen atom of the thiazole ring, in the form of a distorted tetragonal pyramid.     

A dinuclear cyano-bridged complex based on hexacyanoferrate(III) and samarium(III) nitrate: synthesis and crystal structure

A new complex, [Sm(DMF)₄(H₂O)₄Fe(CN)₆]·H₂O (DMF = N, N-dimethylformamide), has been synthesized and characterized by X-ray single crystal structure and thermogravimetric analyses. The complex crystallizes in the P2₁/n space group, with lattice parameters a = 17.583(4) Å, b = 8.870(2) Å, c = 19.845(6) Å, = 95.98(3)°, V = 3078(1) ų, D _x = 1.679 Mg m^–3, D _m = 1.65(1) Mg m^–3, Z = 4. The molecular structure shows that a cyano-bridged bimetallic structure is obtained. The Sm atom is coordinated by eight oxygen atoms of four water molecules and four DMF molecules and one nitrogen atom of the bridging cyanide ligand. The iron atom assumes approximately an octahedral environment surrounded by six CN ligands. The hydrate water molecule is hydrogen-bonded to one of the O atoms bound to Sm. Each terminal CN ligand of the Fe(CN) ₆ ^3– entity is hydrogen-bonded to some O atoms of water molecules. An infrared spectrum is also reported.     

Preparation and crystal structure of diaquabis(1,8-naphthyridine-N-monoxide)nickel(II)nitrate

The title compound [Ni(napyo)₂(H₂O)₂](NO₃)₂ was formed by the reaction of nickel(II) nitrate with 1,8-naphthyridine-N-monoxide (napyo) in ethanol medium. The complex crystallizes in the monoclinic, space groupP2₁/n withZ=2. Lattice parameters are:a=7.160(2),b=11.713(3),c=11.830(2) Å,=95.11(3)°. The structure was determined from 1399 observed reflections and refined toR=0.061. The Ni atom shows a slightly distorted octahedral coordination, being bonded to two oxygen atoms and two nitrogen atoms of two napyo ligands and to two oxygen atoms of two water molecules.     

Crystal and molecular structure of tris-(O-isopropylxanthato)-chromium(III)

The title compound has been synthesized by the reaction of CrCl₃6H₂O with K{S₂COCH(CH₃)₂} in a 13 molar ratio in an aqueous medium. It has been characterized by elemental analysis and IR spectral studies. Crystals of Cr{S₂COCH(CH₃)₂}₃ are monoclinic, space group P2₁/n witha=10.002(2),b=10.973(1),c=18.961(6) Å,=91.78(2)°,V=2079.9 ų,Z=4,D _calc=1.46 g cm^–3, monochromatic radiation (Mo-K), =0.71069 Å,=11.2 cm^–1,F(0 0 0)=948,T=295K, finalR=0.0320 for 2641 reflections. The environment of the chromium atom is based on an octahedral geometry having six sulfur donor atoms from three symmetrically chelated ligands with average distances: Cr-S=2.396(9) Å, C-S=1.690(3) Å and C-O=1.315(3) Å. The bond distance between oxygen atom and the carbon atom of the isopropyl group (O-C_av=1.478(4) Å) suggests that the form –S ₂ ^(–) C=O⁽⁺⁾CH(CH₃)₂ contributes significantly to the structure of the isopropyl group.     

Synthesis and crystal structure of a binuclear maleatocopper(II) complex with phenanthroline

The title copper(II) complex [Cu₂(C₄H₂O₄)₂(phen)₂]⋅4H₂O (phen = 1,10-phenanthroline) was prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to space group C2/c with cell of a = 18.136(5), b = 12.505(5), and c = 14.617(5) Å, β = 103.440(5)^∘ and Z = 4. The Cu(II) atom assumes a square pyramidal coordination geometry with a longer Cu–O3 coordination distance [2.308(3) Å] in the apical direction. The carboxyl O3 atoms from two maleate dianion bridges two Cu(II) atoms to form the binuclear complex with a shorter Cu⋅sCu separation of 3.349(1) Å. The separations of 3.39(1) and 3.41(1) Å between parallel phen rings indicate the existence of aromatic stacking.     

Crystal structures of difluoro[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]boron(III), [BF2(C16H13O3)], and bis[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]copper(II), [Cu(C16H13O3)2]

The crystal structures of difluoro[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]boron(III), [BF₂(C₁₆H₁₃O₃)], and bis[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]copper(II), [Cu(C₁₆H₁₃O₃)₂], have been determined by single-crystal X-ray diffraction methods. The structures were solved by direct methods and electron density calculations and were refined by the full-matrix least-squares method. Difluoro[2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato]-boron(III) crystallizes as yellow rhombs in the monoclinic space groupP2₁/c witha=11.429(3),b=11.364(4),c=11.412(4) Å,=92.19(2)°,V=1481.0(8) ų andZ=4. A total of 2754 unique reflections were collected. Of these 1342 were considered observed [I>3(I)] leading to a finalR-value of 0.045. Boron is tetrahedrally coordinated to the two fluorine atoms and to two oxygen atoms of the bidentate 2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato ligand, C₁₆H₁₃O ₃ ^– . Average bond distances: C-C (aromatic) 1.378(10) Å, B-O 1.473(7) Å and B-F 1.343(4) Å. bis[2-(4-Methoxyphenyl)-3-oxo-3-phenylpropanalato]copper(II) crystallizes as dark yellow-green plates in the monoclinic space groupC2/c witha=23.410(7),b=13.856(3),c=8.039(3) Å,=101.79(2)°,V=2553(1) ų andZ=4. Of the unique set of 3076 scanned reflections 2401 hadI>3(I) for whichR became 0.040. Copper is coordinated to four oxygen atoms, two from each of the two bidentate 2-(4-methoxyphenyl)-3-oxo-3-phenylpropanalato ligands, in a distorted square planar manner. The molecule hasC ₂ symmetry. Average bond distances: C-C (aromatic) 1.383(6) Å and Cu-O 1.896(8) Å. The crystals of both compounds consist of monomeric molecular complexes held together by van der Waals forces.     

Trifluoromethyl group disorder in crystalline 2,8-bis(trifluoromethyl)-4-hydroxymethylquinoline

The title compound crystallized in space groupPna2₁ with lattice constantsa=13.406(1),b=18.799 (4), andc=4.785(1). The molecule is essentially flat with only fluorine atoms, methylene hydrogen atoms, and the hydroxyl hydrogen atom out of the plane of the quinoline ring. Only one of the trifluoromethyl groups of the title compound is disordered following a pattern observed in other crystal structures. Quantum chemical calculations at the AM1 level are consistent with this phenomenon. Although the carbon atom of the fixed trifluoromethyl group is further from the quinoline nitrogen atom than the carbon atom of the disordered trifluoromethyl group, the fluorine atoms of the fixed trifluoromethyl group more closely approach the quinoline nitrogen atom by 0.3 Å if the C(8)–C(10) bond in the crystal structure is freely rotated.National Research Council Associate     

Structure of (1,2-diaminoethane) (1-[[2-[(2-aminoethyl)imino]propyl]thio]-2-propanone)nickel(II) nitrate

A single crystal X-ray investigation of the purple nickel (II) complex Ni[L(en)](NO₃)2, produced by condensation of 1,2-diaminoethane (en) with the thiodiketone S(CH₂COCH₃)2 in the presence of nickel (II) nitrate (L is NH₂(CH₂)₂N=C(CH₃)CH₂SCH₂COCH₃), shows that the metal ions are six coordinate. The new ligand L is tetradentate, with the N,N and S donor atoms arranged meridionally, and the coordination shell completed by the carbonyl oxygen atom of L and the nitrogen atoms of 1,2-diaminoethane. Metal-ligand bond distances are Ni-N: 2.08 av. (en), 2.10 and 2.05 (NH₂ and N=C respectively of L); Ni-O, 2.16; Ni-S, 2.45 Å. There is considerable angular distortion from regular octahedral values of the bond angles at nickel. The crystals are monoclinic,P2₁/c (No. 14),a=12.433(2),b=11.709(1),c=13.150(2) Å,=103.93(1)°,V _c=1858.2(4) ų. The structure was solved by the heavy-atom method and refined by full-matrix least squares to anR value of 0.055 for 3633 reflections.     

A novel four-coordinate zinc(II) complex of the di-N-hydroxypropylated tetraaza macrocycle

The compound [Zn(L²)Cl]ClO₄·H₂O (1) (L² = 2,13,-bis(3-hydroxypropyl)-5,16-di-methyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) has been synthesized and structurally characterized. 1 crystallizes in the monoclinic system, space group P2₁/c with a = 8.932(2), b = 16.189(2), c = 22.492(4) Å = 95.34(2)° V = 3238.3(11) ų; and Z = 4. The zinc atom is placed in a highly distorted tetrahedral environment bonding with three nitrogen atoms of the macrocycle and one chlorine atom.     

Crystal structure of [Mn2(III)(salpa)2Cl2(H2O)2] (H2salpa = 1-(salicylaldeneamino)-3-hydroxypropane)

The manganese complex, (Mn₂(III)(salpa)₂Cl₂(H₂O)₂], has been prepared and its structure determined using x-ray crystallography. The dimer is a di-₂-alkoxo complex which is a six-coordinate manganese dimer with unsupported alkoxide bridges and a rare example of a chloride- and water-containing manganese dimer. The complex crystallizes in the monoclinic space group P2₁/c with a = 9.315(5), b = 11.130(4), c = 11.637(5) Å, = 104.33(3)°, V = 1169.0(9) ų, and Z = 2. The structure comprises discrete binuclear clusters in which the metal atoms are bridged by two alkoxo oxygens of the salpa^2– ligands. The Mn—O and Mn—N distances are in good agreement with those found for other manganese(III) Schiff base complexes. The Mn—Cl and Mn—O3 distances are 2.585(2) and 2.371(2) Å, respectively, and the Mn ··· Mn distance is 3.001(1) Å. In the crystal, there are two types of hydrogen bonding between the H₂O molecule and the Cl atom with Cl ··· H(H₂O) distance of 2.33(6) (intramolecule: –1 + x, y, –1 + z) and 2.68(6) Å (intermolecule: –1 + x, 0.5–y, –0.5 + z).     

Molecular structure of thiocyanatotris (2,2′-iminodiethanoldithiocarbamato) tellurium(IV) monohydrate

The synthesis, properties, and structural characterization of the title compound, C₁₆H₃₀N₄O₄S₇Te(IV)·H₂O, are reported. The crystals are monoclinic, space groupP2₁/n, withZ=4 in a unit cell of dimensionsa=13.291(5),b=21.306(6),c=10.450(1) Å, 0=104.25(2)° and,V _c=2868 ų. The structure was solved by the heavy atom method and refined by full-matrix least squares toR=0.025 andR _w =0.027 for 2894 reflections. The dithiocarbamate groups are linked in an unequal bidentate manner with Te-S average distance 2.695(1) Å. The thiocyanate group is bonded through the sulfur atom with much larger Te-S length [2.964(2) Å].     

Synthesis, Crystal Structure and Cytotoxic Property of Bis(4-chlorobenzoato)bis[1-(2-aminoethyl)piperidine]disilver(I)

Abstract  

4-Chlorobenzoic acid reacts with silver oxide and 1-(2-aminoethyl)piperidine to give a dinuclear silver(I) complex, [Ag₂(C₇H₄ClO₂)₂(C₇H₁₆N₂)₂]. The complex was characterized by elemental analysis and X-ray diffraction. The complex crystallizes in the triclinic space group P−1 with unit cell dimensions a = 6.8550(10), b = 8.7370(10), c = 13.859(2) ?, α = 73.213(3), β = 87.945(3), γ = 77.050(3)°, V = 774.09(18) ?³, Z = 1, R ₁ = 0.0386, and wR ₂ = 0.0791. The dimeric Ag complex is located on an inversion center. The Ag atom in the complex is three-coordinated by two N atoms from two 1-(2-aminoethyl)piperidine ligands and by one O atom of a 4-chlorobenzoate ligand, forming a triangular coordination. In the crystal structure, the molecules are linked through intermolecular N–H···O hydrogen bonds, forming chains running along the a axis. The complex shows high cytotoxic property to both normal and carcinoma cells.     

Crystal and molecular structure of 3-(2-(1,10-phenanthrolyl))-5,6-diphenyl-1,2,4-triazine-chloroaquotriphenyltin(IV) (1:1)

3-(2-(1,10-Phenanthrolyl))-5,6-diphenyl-1,2,4-triazine-chloroaquotriphenyl-tin(IV) (1:1) crystallizes in the orthorhombic system:a=19.195,b=9.144,c=21.642 Å,Z=4, space groupPca2₁ (No. 29). The structure was determined using the procedure for difference structures (Dirdir) with CuK diffractometer data, and refined by block-diagonal least squares toR=0.031 for 3287 observed reflections. The tin atom is 5-coordinate with the three phenyl groups forming the equatorial plane. A chlorine atom and a water molecule complete the coordination. The triazine moiety does not coordinate directly to the metal atom. The only interaction is due to two N H-O hydrogen bonds formed between two nitrogen atoms from the ligand and the water molecule.