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.      

Unexpected crystallization and X-ray crystal structure of racemic 1-phenyl-2-(4-pyridyl)ethanol intermediate

We have isolated, by crystallization, the intermediate, 1-phenyl-2-(4-pyridyl)ethanol, from the condensation reaction of 4-methylpyridine with benzaldehyde in which the aim was to obtain the model compound 4-styrylpyridine in absence of a condensing agent. Single crystal X-ray analysis shows the formation of an intermolecular hydrogen bond O–H···N between the nitrogen atom of a pyridine group and the oxygen atom of the OH of the neighboring molecule, which helps to stabilize the crystal structure. Crystal structure determination clearly revealed that the solid is chiral and racemic, as expected. The title compound crystallizes in an orthorhombic system with a space group Pna2₁ with two pairs of R and S enantiomers in each crystal cell (a = 15.591(1) Å, b = 12.691(1) Å, and c = 5.589(1) Å). Spectroscopic NMR data gave evidence that the isolated compound is actually the alcohol just before the dehydration process that yields the double bond of the 4-styrylpyridine.     

A two-dimensional Zn(II) coordination polymer with a three-dimensional supramolecular architecture comprising 5-dimethylamino-isophthalic acid and 1,3-bis(4-pyridyl)propane

A new zinc coordination polymer, [Zn(L)(bpp)·H₂O]_n, was synthesized using 5-dimethylamino-isophthalic acid (H₂L) and 1,3-bis(4-pyridyl)propane (bpp) as organic linkers. In the complex, adjacent Zn²⁺ ions are linked by L^2? anions to form a one-dimensional (1D) [ZnL]_n chain. Then bpp ligands expand the 1D chains into a corrugated two-dimensional (2D) layer network by linking neighboring Zn²⁺ ions. These adjacent layers are further stacked together by direct C?H···π supramolecular interactions, generating a three-dimensional (3D) supramolecular structure. From the viewpoint of topology, the 2D network can be rationalized to a uninodal four-connected non-interpenetrated sql/Shubnikov tetragonal plane net with {4⁴.6²} topology. Moreover, the solid state properties such as thermogravimetric analysis and luminescence were also investigated.     

The synthesis and crystal structure of new 3,6-bis[1-(4-ethoxyphenyl)-5-methyl-1,2,3- triazol-4-yl]-<Emphasis Type="Italic">s</Emphasis>-triazolo[3,4-b]-1,3,4-thiadiazole

The 3,6-bis[1-(4-ethoxyphenyl)-5-methyl-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiad- iazole was synthesized from p-ethoxyaniline to 8 with 1-(4-ethoxyphenyl)-5-methyl-1,2,3-triazol-4-caroxylic acid. The yielded product 9 was investigated with X-ray crystallographic, NMR, MS, and IR techniques. Compound 9, C₂₅H₂₄N₁₀O₂S, Mr = 528.60, crystallizes in the triclinic space group P < eqid1 > . V = 1276.6(4) ų, Z = 2, Dx = 1.375 Mgm^–3. The final R was 0.0589.     

EPR spectra of (L-aspartate)di(2-pyridyl)aminezinc(II) hydrate substitutionally copper(II) doped complex

The [(L-aspartate)di(2-pyridyl)aminezinc(II)]hydrate doped with traces of copper was prepared. Electron paramagnetic resonance spectra of the polycrystalline sample were recorded at room temperature by using the X-band of the EPR spectrometer. The observedg factors for the complex areg _‖=2.258 andg _⊥=2.066. TheA _‖ value is 165.10⁻⁴ cm⁻¹. The crystal and molecular structure of the complex are also reported. The complex crystallizes in the monoclinic system; space groupP2₁ witha=7.2053(11),b=10.447(2),c=10.812(2) Å, β=108.489(14)° andZ=2. The structure can be described in the crystal lattice as polymeric chains.     

EPR spectra of (L-aspartate)di(2-pyridyl)aminezinc(II) hydrate substitutionally copper(II) doped complex

The [(L-aspartate)di(2-pyridyl)aminezinc(II)]hydrate doped with traces of copper was prepared. Electron paramagnetic resonance spectra of the polycrystalline sample were recorded at room temperature by using the X-band of the EPR spectrometer. The observedg factors for the complex areg _‖=2.258 andg _⊥=2.066. TheA _‖ value is 165.10⁻⁴ cm⁻¹. The crystal and molecular structure of the complex are also reported. The complex crystallizes in the monoclinic system; space groupP2₁ witha=7.2053(11),b=10.447(2),c=10.812(2) Å, β=108.489(14)° andZ=2. The structure can be described in the crystal lattice as polymeric chains.     

Synthesis and crystal structure of a novel polymeric silver(I) complex

The complex of [Ag₂(μ–L)₂(μ–NO₃)₂]_n, where L?=?2–methyl–5–(2–pyridyl)–1,3,4–oxadiazole, has been synthesized and characterized by single–crystal X–ray diffraction analysis. The crystals are in triclinic system with space group P–1. Complex [Ag₂(μ–L)₂(μ–NO₃)₂]_n is a polymeric silver(I) complex bridged through the 1,3,4–oxadiazole rings and the nitrate ions, and the center Ag1(I) atoms have distorted trigonal bipyramidal geometries [AgN₃O₂].     

Synthesis, crystal structures, and properties of two manganese(II)-nitroprusside complexes

Two new manganese(II)-1,10-phenanthroline-nitroprusside complexes, [Mn(phen)₃][Fe (CN)₅(NO)]⋯2H₂O⋯0.25CH₃OH (1) and [Mn(phen)₂(H₂O)₂][Fe(CN)₅(NO)]⋯H₂O (2) (where phen is 1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction, electronic paramagnetic resonance (E.P.R.) and IR analyses. Complex 1 crystallizes in the monoclinic space group P2₁/n, with lattice parameters a = 10.0441(15) Å, b = 19.668(2) Å, c = 19.938(3) Å,  β =100.427(14)°, V = 3873.7(10) ų, Z = 4; complex (2) crystallizes in the monoclinic space group C2/c, with a = 17.120(2) Å, b = 13.7925(19) Å, c = 14.4362(17) Å, β = 107.962(12)°, V = 3242.6(7) ų, Z = 4. In the two compounds, three phen ligands 1, or two phen ligands and two cis-related aqua molecules 2, are in a distorted octahedral arrangement around the Mn(II) ion. The nitroprusside anion, [Fe(CN)₅(NO)]²⁻, acts as a counterion. It is intriguing that in complex 2 no cyano bridges are present with two water molecules coordinated to the Mn(II) ion considering that usually the cyano nitrogen atoms are strong donors and could readily replace the coordinating solvent water molecules. Abundant hydrogen bond interactions and π–π stacking between the phen rings in two complexes lead to three-dimensional supramolecular networks.     

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.     

X-ray crystal and molecular structure of [3,6-bis(2-pyridyl)pyridazine-N 1,N2]bis(triphenylphosphine) copper(I) hexafluorophosphate

[3,6-bis(2-pyridyl)pyridazine-N ¹,N²]bis(triphenylphosphine) copper(I) hexafluorophosphate crystallizes in space group $P\bar 1$ with cell dimensionaa=14.050(2),b=11.941(2),c=15.200(2) Å, α=71.28(1), β=67.02(1), and γ=84.78(2)^o. In the title compound, the mononuclear cation consists of a tetrahedral copper(I) center involving two nitrogen donors of the 3,6-bis(2-pyridyl)pyridazine (dppn) and two P atoms of the triphenylphosphine molecules. In the dppn ligand the two non-coordinating N atoms (one from pyridine and one from pyridazine) are mutallytrans.     

Syntheses and crystal structures of two polymorphs of three‐dimensional silver (I) 5‐(3‐aminophenyl)tetrazolates

Two polymorphs of silver 5‐(3‐aminophenyl)tetrazolates – α‐ and β‐Ag(amphttz) have been obtained by the reaction of amphttzH with AgNO₃ in presence of ammonia either in ambient condition or under the hydrothermal condition, respectively (amphttzH = 5‐(3‐aminophenyl)tetrazole). Both of the two phases of Ag(amphttz) were characterized by elemental analyses, IR spectra and single‐crystal X‐ray diffraction. X‐ray analysis shows α‐, β‐phases crystallize in P ‐1 with a = 8.551 (2) Å, b = 8.720(2) Å, c = 11.173(2) Å, α = 98.15(3)°, β = 90.95(3)°, γ = 95.45(3)° and C 2/c with a = 13.542(3) Å, b = 10.135(2) Å, c = 12.610(3) Å, β = 113.58(3)°, respectively. The two polymorphs exhibit different 3D structures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The structure of [Co(H-tptz)Cl3]·H2O (tptz=2,4,6-tri(2-pyridyl)-1,3,5-triazine) prepared by crystallization from the ionic liquid, N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide

The structure of tris-chloro[2,6-bis(2′-pyridyl)-4-(2′-pyridinium)-1,3,5-triazine]cobalt(II) monohydrate, [Co(C₁₈H₁₃N₆)Cl₃]·H₂O (C2/c (No. 15), a=7.783(11), b=22.42(3), c=11.001(15) ?, β=90.05(2)°), crystallized from the open air reaction of CoCl₂ and 2,4,6-tri(2-pyridyl)-1,3,5-triazine in the ionic liquid, N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide is reported. The structure consists of six coordinate cobalt in an octahedral geometry bonded to the tridentate tptz ligand and three chlorines. The non-coordinating pyridyl group in the tptz ligand is protonated (with the protonated nitrogen crystallographically disordered over two possible sites), providing overall charge neutrality for the complex.     

Synthesis,Crystal Structure and Fluorescent Study of Bis(2-(2-hydroxyphenyl)benzimidazolate)zinc with Ethanol Solvate

Abstract  The zinc(II) complex with 2-(2-hydroxyphenyl)benzimidazole, namely [Zn(2-(2-hydroxyphenyl)benzimidazolate)₂]·C₂H₅OH (1 · C₂H₅OH) has been synthesized and characterized by X-ray crystallography and photoluminescent analysis. The complex crystallizes in monoclinic space group P2₁/c with cell parameters a = 10.156(1) ?, b = 25.771(3) ?, c = 9.674(1) ?, α = 90°, β = 103.641(2)°, γ = 90°, Z = 4, V = 2460.4(4) ?³. The central Zn(II) is four-coordinate and has a tetrahedral geometry. The steady-state and time-resolved photoluminescent spectra for the title compound have also been studied. The emission property can be ascribed to ligand-centered charge-transfer transition (LCCT) with π → π* property. Index Abstract   A new co-crystal of Zn(II) complex of 2-(2-hydroxylphenyl)benzimidazole with ethanol solvate has been prepared, characterized by X-ray crystallography and fluorescent studies.      

Synthesis and crystal structure of a 2D (6,3) coordination network, {[Ag(L)1.5]NO3} n [L = 1,3-bis(benzylthio)propane]

A new dithioether silver(I) complex, {[Ag(L)_1.5]NO₃} _n (1) has been prepared by the reaction of AgNO₃ with 1,3-bis(benzylthio)propane (L) in methanol/chloroform. The structure was characterized by single-crystal X-ray diffraction analysis: rhombohedral system, space group R –3c, with a =b = 15.651(7), c = 39.26(4) Å, V = 8328(1) ų, and Z = 6. The crystal structure consists of [Ag(L)_1.5]⁺ cations and NO₃ ^– anions. In 1, each silver(I) center is coordinated equivalently to three sulfur donors from three different ligands to give a trigonal-planar coordination geometry. Each L links two adjacent silver(I) centers in bis-monodentate bridging mode to form a 2D (6,3) network sheet. Furthermore, these 2D sheets are linked by the weak coordination interactions between nitrate ions and silver(I) atoms to form a 3D brick-wall framework.     

Synthesis and Crystal Structure of 2-(2,3,4-Trimethoxy-6-Methylbenzylideneamino)phenol

Abstract  The title compound 2-(2,3,4-trimethoxy-6-methylbenzylideneamino)phenol (C₁₇H₁₉NO₄, M _r = 301.33) was synthesised and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 10.4458(14), b = 8.3870(10), c = 17.780(2) ?, β = 91.102(2)^°, V = 1557.4(3) ?³, Z = 4, D _c = 1.285 g/cm³, λ = 0.71073 ?, μ(Mo Kα) = 0.092 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0452, wR(F ²) = 0.1065 for 2,743 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the molecule adopts an E configuration at the C=N functional bond. The dihedral angle between the two phenyl rings is 38.3(3)°. The crystal structure is stabilized by C–H···O, O–H···O and O–H···N hydrogen bonds and π–π stacking interactions. Graphical Abstract  The title compound 2-(2,3,4-trimethoxy-6-methylbenzylideneamino)phenol (C₁₇H₁₉NO₄, M _r = 301.33) was synthesised and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 10.4458(14), b = 8.387(1), c = 17.780(2) ?, β = 91.102(2)°, V = 1557.4(3) ?³, Z = 4, D _c = 1.285 g/cm³, λ = 0.71073 ?, μ(Mo Kα) = 0.092 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0452, wR(F ²) = 0.1065 for 2,743 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the molecule adopts an E configuration at the C=N functional bond. The dihedral angle between the two phenyl rings is 38.3(3)°. The crystal structure is stabilized by C–H···O and O–H···O hydrogen bonds and π–π stacking interactions.      

Synthesis and crystal structure of bis(4-methylpiperidine-dithiocarbamato-S,S′)-palladium(II)

The complex bis(4-methylpiperidine-dithiocarbamato-S,S′)-palladium(II) was synthesized by the reaction of 4-methyl-1-piperidine dithiocarbamic acid with palladium(II) chloride. Its structure was determined by X-ray crystal diffraction analysis. It crystallizes in the monoclinic P2₁/c space group with the crystal cell parameters a=8.6491(8) ?, b=18.7305(16) ?, c=11.9933(10) ?, β=107.074(1)°, V=1857.3(3) ?³ and Z=4. The palladium (II) ion is bonded to four sulfur atoms, belonging to two dithiocarbamate ligands, in a distorted square planar geometry. The X-ray data suggest a pronounced electronic delocalization in the two NCS₂ moieties.     

Synthesis and Crystal Structures of Bromo(1,10-phenanthroline- N , N ′)tris(2-cyanoethyl)phosphinocopper(I) and Bromo(2,2′-bipyridine- N , N ′)tris(2-cyanoethyl)phosphinocopper(I)

The two new complexes bromo(1,10-phenanthroline-N,N′)tris(2-cyanoethyl)phosphinocopper(I) and bromo(2,2′-bipyridine-N,N′)tris(2-cyanoethyl)phosphinocopper(I) were synthesized and their X-ray crystal structures were determined. The first complex crystallizes in the triclinic space group P-1 with the crystal cell parameters a = 7.7596(7) ?, b = 11.470(1) ?, c = 12.803(1) ?, α = 78.884(1)^°, β = 79.759(1)^°, γ = 86.867(1)^°, V = 1100.0(2) ?³ and Z = 2. The second complex crystallizes in the orthorhombic space group Pbca with the crystal cell parameters a = 10.614(1) ?, b = 12.345(1) ?, c = 31.903(3) ?, V = 4180.3(7) ?³ and Z = 8. In both compounds, the copper(I) ion is four-coordinate with a distorted tetrahedral geometry. In the 1,10-phenanthroline complex, an intermolecular dipole–dipole interaction between two cyano groups stabilizes an unfavorable synclinal conformation of one cyanoethyl group of the phosphine ligand.     

Synthesis and crystal structure of the copper(I) complex with 2-[(o-pyridyl)-sulfanylmethyl]-pyrimidine ligand

The reaction of a flexible monothioether ligand, 2-[(o-pyridyl)-sulfanylmethyl]-pyrimidine (L), with CuI leads to the formation of a novel complex [Cu₄I₄(L)₂] (1), which has been characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction analysis: monoclinic, space group P2₁/n, with a = 10.921(5), b = 10.824(5), c = 13.128(6) Å, β = 109.333(5)° and Z = 2. Single-crystal X-ray analyses show that complex 1 is tetranuclear structure with a distorted chair-like Cu₄I₄ skeleton. Cu···Cu interactions are found to exist in this tetranuclear molecule. In the packing mode of complex 1, there exist N⋯⋯⋯I weak interactions and intermolecular π–π contacts. These weak interactions not only stabilize the structure of complex, but also further link the tetranuclear molecules into a high-dimensional supramolecular architecture.     

Synthesis and crystal structure of aquo-N-(2-hydroxyphenylmethenylimino)-1, 5-diamine-3-azapentanecopper(II), chloride

The title compound is [CuL(H₂O)]Cl, C₁₁H₁₈N₃ClO₂Cu, where L is N-(2-hydro- xyphenylmethenylimino)-1,5-diamine-3-azapentane. In the cation the metal atom is coordinated by three N and two O atoms from L and a water molecule in a distorted square-pyramidal geometry.     

Synthesis, properties, and X-ray structure of [Cu(dpa)Cl2] (dpa = di-(2-picolyl)amine)

The mono(dpa)copper(II) complex [Cu(dpa)Cl₂] (1) (dpa = di-(2-picolyl)amine) has been synthesized and structurally characterized. It crystallizes in the monoclinic system P2₁/n with a = 8.155(1), b = 12.560(1), c = 12.817(2) Å, = 91.64(2)°, V = 1312.3(2) ų, Z = 4. The copper atom is coordinated by three nitrogen atoms from the dpa ligand and two chlorides in a distorted square-pyramidal environment. Cyclic voltammetric data show that 1 undergoes the reversible one-electron oxidation to the Cu(III) and the reversible one-electron reduction to the Cu(I) state.