Search

Abstract: Structural and conformational properties of the molecule bis[isopropoxy(thiocarbonyl)]sulfide, [(CH3)2CHOC(S)]2S, have been studied by vibrational spectroscopy (IR and Raman) and quantum chemical calculations (HF and B3LYP with 6-31+G∗ basis sets). The crystal and molecular structure of the title compound was determined by X-ray diffraction methods. It crystallizes in the monoclinic C2/c space group with a =8.4007(4), b =13.5936(5), c =10.3648(5)Å, β =106.024(4)° and Z =4 molecules per unit cell. The molecules are sited on a crystallographic twofold axis passing through the sulphide atom and arranged in layers perpendicular to the b-axis. The solid state IR and Raman spectra of the compound give no sign of any other rotamer. [Copyright &y& Elsevier]

Examines the reaction between thiamine diphosphate hydrochloride and methylphenyltin chloride in water. Molecular and crystal structure of the oxygen-capped cluster; Detection of hydrogen-bonded oxygen in nonterminal phosphate.

Reaction of trans-Ru(DMSO)4C12 with DMAP (DMAP = 4-dimethylaminopyridine) yields the yellow [Ru(DMAP)6]2~ cation in good yield. The crystal and molecular structure of [Ru(DMAP)6]Cl2.6CH3CH2OH was determined by X-ray diffraction methods. The complex crystallizes in the trigonal F~3 space group with a = b = 16.373(1), c = 20.311(1) A, y = 120°, and Z = 3 molecules per unit cell. The reaction of [Ru(DMAP)6]2~ in aerobic water gives the red [Ru'°(DMAP)5(OH)]2~ cation. This complex shows a chemical behavior similar to [Ru'°(NH3)5Cl]2~ and allows the preparation of a family of [Ru(DMAP)5L]'~ complexes. Their electronic properties indicate that the {Ru°(DMAP)5} fragment is a weaker 7r-donor than {Ru"(NH3)5}. Our density functional theory (DFT) calculations show that in {RuH(DMAP)5} the DMAP ligands can compete for the ~r electron density of the ruthenium making the fragment a weaker ir-donor. [ABSTRACT FROM AUTHOR]

We report here on three new ruthenium(II) complexes, [Ru(DPEPhos)(mtz)(bipy)]PF 6 (Ru1), [Ru(DPEPhos)(mmi)(bipy)]PF 6 (Ru2) and [Ru(DPEPhos)(dmp)(bipy)]PF 6 (Ru3). DPEPhos = bis -[(2-diphenylphosphino)phenyl]ether, mtz = 2-mercapto-2-thiazoline, mmi = 2-mercapto-1-methylimidazole, dmp = 4,6-diamino-2-mercaptopyrimidine and bipy = 2,2′-bipyridine. The compounds were characterized by several spectroscopic techniques, and the molecular structure of Ru1 complex was determined by single-crystal X-ray diffraction. The cytotoxicity of Ru1 – Ru3 complexes were tested against the A549 (human lung) and the MDA-MB-231 (human breast) cancer cell lines and against MRC-5 (non-tumor lung) and MCF-10A (non-tumor breast) cell lines through the MTT assay. All three complexes are cytotoxic against the cell lines studied, with IC 50 values lower than those found for the cisplatin. Among them, the Ru2 complex has shown the best selectivity against MDA-MB-231 cancer cell lines, with an IC 50 value 12 times lower than that on MCF-10A. The complex Ru2 was capable to induce changes in MDA-MB-231 cells morphology, with loss of cellular adhesion, inhibited colony formation and induce an accumulation of cells at the sub-G1 phase, with an increase in S-phase and decrease of cells at G2 phase. Viscosity, electrochemical and Hoechst 33258 displacement experiments for Ru1 – Ru3 complexes with calf thymus DNA (CT-DNA) showed an electrostatic and groove binding mode of interaction. Additionally, the complexes interact with the protein Human Serum Albumin (HSA) by static mechanism. The negative values for ΔH and ΔS indicate that van der Waals forces and hydrogen bonding may occurs between the complexes and HSA. Therefore, this class of complexes are promising anticancer candidates and may be selected to further detailed studies. N,S-mercapto ligands can form new ruthenium compounds with promising cytotoxic activity against cancer cell lines. [Display omitted] • Ru(II)/N,S-mercapto complexes with promising anticancer properties. • Cytotoxic activity against breast and lung cancer cells. • Selectivity is reported against breast cancer cells. • Complexes interact with CT-DNA and Human Serum Albumin (HSA). • Complex inhibited colony formation and induce an accumulation of cells at the sub-G1 phase. [ABSTRACT FROM AUTHOR]

1-Acyl thioureas [R 1 C(O)NHC(S)NR 2 R 3 ] are shown to display conformational flexibility depending on the degree of substitution at the nitrogen atom. The conformational landscape and structural features for two closely related thioureas having R 1 = 2-furoyl have been studied. The un-substituted 2-furoyl thiourea ( I ) and its dimethyl analogue, i.e. 1-(2-furoyl)-3,3-dimethyl thiourea ( II ), have been synthesized and fully characterized by spectroscopic (FT-IR, 1 H and 13 C NMR) and elemental analysis. According to single crystal X-ray diffraction analysis, compounds I and II crystallize in the monoclinic space group P21/c. In the compound I , the trans–cis geometry of the almost planar thiourea unit is stabilized by intramolecular N H ⋯ O C hydrogen bond between the H atom of the cis thioamide and the carbonyl O atom. In compound II , however, the acyl thiourea group is non-planar, in good agreement with the potential energy curve computed at the B3LYP/6-31 + G(d,p) level of approximation. Centrosymmetric dimers generated by intermolecular N H ⋯ S C hydrogen bond forming R 2 2 (8) motif are present in the crystals. Intermolecular interactions have been rationalized in terms of topological partitions of the electron distributions and Hirshfeld surface analysis, which showed the occurrence of S ⋯ H, O ⋯ H and H ⋯ H contacts that display an important role to crystal packing stabilization of both thiourea derivatives. [ABSTRACT FROM AUTHOR]

Abstract: Complexes [Zn2(HL1)2(CH3COO)2] (1) and [Zn2(L2)2] (2) were synthesized with salicylaldehyde semicarbazone (H2L1) and salicylaldehyde-4-chlorobenzoyl hydrazone (H2LASSBio-1064, H2L2), respectively. The crystal structure of (1) was determined. Upon recrystallization of previously prepared [Zn2(HL2)2(Cl)2] (3) in 1:9 DMSO:acetone crystals of [Zn2(L2)2(H2O)2]·[Zn2(L2)2(DMSO)4] (3a) were obtained. The crystal structure of 3a was also determined. All crystal structures revealed the presence of phenoxo-bridged binuclear zinc(II) complexes. [Copyright &y& Elsevier]

Abstract: The “Ru(P–P)” unit (P–P=diphosphine) is recognized to be an important core in catalytic species for hydrogenation of unsaturated organic substrates. Thus, in this study we synthesized six new complexes containing this core, including the binuclear complex [(dppb)(CO)Cl2Ru-pz-RuCl2(CO)(dppb)] (pz=pyrazine) which can be used as a precursor for the synthesis of cationic carbonyl species of general formula [RuCl(CO)(dppb)(N–N)]PF6 (N–N=diimine). Complexes with the formula [RuCl(py)(dppb)(N–N)]PF6 were synthesized by exhaustive electrolysis of these carbonyl compounds or from the precursors [RuCl2(dppb)(N–N)]. The new complexes were characterized by microanalysis, conductivity measurements, IR and 31P{1H} NMR spectroscopy, cyclic voltammetry and X-ray crystallography. [Copyright &y& Elsevier]

Abstract: The structural, spectroscopic and theoretical study of cyclocreatine (1-carboxymethyl-2-iminoimidazolidine, CyCre) has been performed prompted by the biological relevance of the molecule and its potential role as a ligand in biometalic compounds. The crystal structure of CyCre has been determined by X-ray diffraction methods. The compound crystallizes as a zwitterion in the monoclinic system, space group P21/c. The crystal is further stabilized by a network of N–H⋯O bonds. Infrared and Raman spectra of the solid, electronic spectra of aqueous solutions at different pH values and 1H and 13C NMR spectra have been recorded and analyzed. Band assignments were accomplished with the help of theoretical calculations. Optimized molecular geometries, harmonic vibrational frequencies and molecular electrostatic potentials were calculated using methods based on the density functional theory. [Copyright &y& Elsevier]

Abstract: Structural and conformational properties of 1H-Isoindole-1,3(2H)-dione, 2-[(methoxycarbonyl)thio] (S-phthalimido O-methyl thiocarbonate) are analyzed using a combined approach including X-ray diffraction, vibrational spectra and theoretical calculation methods. The vibrational properties have been studied by infrared and Raman spectroscopies along with quantum chemical calculations (B3LYP and B3PW91 functional in connection with the 6-311++G** and aug-cc-pVDZ basis sets). The crystal structure was determined by X-ray diffraction methods. The substance crystallizes in the monoclinic P21/c space group with a =6.795(1), b =5.109(1), c =30.011(3)Å, β =90.310(3)° and Z =4 molecules per unit cell. The conformation adopted by the Nh name="sbnd" />Cs syn (Cbond in synperiplanar orientation with respect to the Nbond). The experimental molecular structure is well reproduced by the MP2/aug-cc-pVDZ method. [Copyright &y& Elsevier]

Two new complexes of platinum(II) and silver(I) with acesulfame were synthesized. Acesulfame is in the anionic form acesulfamate (ace). The structures of both complexes were determined by X-ray crystallography. For K2[PtCl2(ace)2] the platinum atom is coordinated to two Cl− and two N-acesulfamate atoms forming a trans-square planar geometry. Each K+ ion interacts with two oxygen atoms of the S( ═ O)2 group of each acesulfamate. For the polymeric complex [Ag(ace)]n the water molecule bridges between two crystallographic equivalent Ag1 atoms which are related each other by a twofold symmetry axis. Two Ag1 atoms, related to each other by a symmetry centre, make bond contact with two equivalent oxygen atoms. These bonds give rise to infinite chains along the unit cell diagonal in the ac plane. The in vitro cytotoxic analyses for the platinum complex using HeLa (human cervix cancer) cells show its low activity when compared to the vehicle-treated cells. The Ag(I) complex submitted to in vitro antimycobacterial tests, using the Microplate Alamar Blue (MABA) method, showed a good activity against Mycobacterium tuberculosis, responsible for tuberculosis, with a minimal inhibitory concentration (MIC) value of 11.6μM. The Ag(I) complex also presented a promising activity against Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive (Enterococcus faecalis) microorganisms. The complex K2[PtCl2(ace)2] was also evaluated for antiviral properties against dengue virus type 2 (New Guinea C strain) in Vero cells and showed a good inhibition of dengue virus type 2 (New Guinea C strain) replication at 200μM, when compared to vehicle-treated cells. [Copyright &y& Elsevier]

Abstract: 3′-Azido-3′-deoxythymidine (zidovudine, AZT), a synthetic analog of natural nucleoside thymidine, has been used extensively in AIDS treatments. We report here the synthesis, X-ray crystal and molecular structure, NMR, IR and Raman spectra and the thermal behavior of a novel carbonate of AZT [(AZT–O)2Cred by the reaction of zidovudine with carbonyldiimidazole. The carbonate compound, C21H24N10O9, crystallizes in the tetragonal space group P41212 with a = b =15.284(1), c =21.695(1)Å, and Z =8 molecules per unit cell. It consists of two AZT moieties of closely related conformations which are bridged by a carbonyl group to adopt a folded Z-like shape. [Copyright &y& Elsevier]

Abstract: In the present work 2-formylpyridine-para-chloro-phenyl hydrazone (H2FopClPh) and 2-formylpyridine-para-nitro-phenyl hydrazone (H2FopNO2Ph) were obtained, as well as their copper(II) and zinc(II) complexes [Cu(H2FopClPh)Cl2] (1), [Cu(2FopNO2Ph)Cl] (2), [Zn(H2FopClPh)Cl2] (3) and [Zn(H2FopNO2Ph)Cl2] (4). Upon re-crystallization in DMSO:acetone conversion of 2 into [Cu(2FopNO2Ph)Cl(DMSO)] (2a) and of 4 into [Zn(2FopNO2Ph)Cl(DMSO)] (4a) occurred. The crystal structures of 1, 2a, 3 and 4a were determined. [Copyright &y& Elsevier]

Abstract: Pure O-methyl N-methoxycarbonyl thiocarbamate CH3OC(S)N(H)C(O)OCH3 (I) and O-ethyl N-methoxycarbonyl thiocarbamate, CH3CH2OC(S)N(H)C(O)OCH3 (II), are quantitatively prepared by the addition reaction between the CH3OC(O)NCS and the corresponding alcohols. The compounds are characterized by multinuclear (1H and 13C) and bi-dimensional (13C HSQC) NMR, GC–MS and FTIR spectroscopy techniques. Structural and conformational properties are analyzed using a combined approach involving crystallographic data, vibration spectra and theoretical calculations. The low-temperature (150K) crystal structure of II was determined by X-ray diffraction methods. The substance crystallizes in the monoclinic space group P21/n with a =4.088(1)Å, b =22.346(1)Å, c =8.284(1)Å, β =100.687(3)° and Z =4 molecules per unit cell. The conformation adopted by the thiocarbamate group –OC(S)N(H)– is syn (Cbond in synperiplanar orientation with respect to the N–H single bond), while the methoxycarbonyl Cbond is in antiperiplanar orientation with respect to the N–H bond. The non-H atoms in II are essentially coplanar and the molecules are arranged in the crystal lattice as centro-symmetric dimeric units held by N−H···Sn bonds [d(N···S)=3.387(1)Å, ∠(N−H···S)=166.4(2)°]. Furthermore, the effect of the π electronic resonance in the structural and vibrational properties is also discussed. [Copyright &y& Elsevier]

Abstract: 2-Benzoylpyridine-methyl hydrazone (HBzMe) has been obtained as well as its copper(II) [Cu(HBzMe)Cl2] (1) and zinc(II) [Zn(HBzMe)Cl2] (2) complexes. Upon re-crystallization in 1 – 9 DMSO:acetone conversion of 1 into dimeric [Cu(BzMe)Cl]2 (1a) occurred. The crystal structures of HBzMe, 1, 1a, and 2 were determined. HBzMe adopts the ZE conformation in the solid. In all complexes the hydrazone adopts the E configuration to attach to the metal through the Npy ph name="sbnd" />O chelating system. In 1 and 2 a neutral hydrazone coordinates to the metal center while in 1a deprotonation occurs with coordination of an anionic ligand. 1a presents a dimeric structure, having two copper(II) ions per asymmetric unit. Two chlorides are also present in the copper coordination sphere, which act as bridging ligands and connect the copper centers to each other. [Copyright &y& Elsevier]

Abstract: Pure N,N′-di(methoxycarbonylsulfenyl)urea, [CH3OC(O)SNH]2CO, is quantitatively prepared by the hydrolysis reaction of CH3OC(O)SNCO and characterized by 1H NMR, GC–MS and FTIR spectroscopy techniques. Structural and conformational properties are analyzed using a combined approach with data obtained from X-ray diffraction, vibrational spectra and theoretical calculation methods. The IR and Raman spectra for normal and deuterated species are reported. The crystal structure of [CH3OC(O)SNH]2CO was determined by X-ray diffraction methods. The substance crystallizes in the orthorhombic P21212 space group with a =9.524(2), b =12.003(1), c =4.481(1)Å, and Z =2 moieties in the unit cell. The molecule is sited on a twofold crystallographic axis (C 2) parallel to c and shows the anti–anti conformation (S–N single bonds antiperiplanar with respect to the opposite C–N single bonds in sulfenyl-ureasic group). Neighboring molecules are arranged in a chain motif that extends along the C 2-axis and is held by bifurcated NH⋯O⋯HN intermolecular bonds. A local planar symmetry is observed in the crystal for the central –SN(H)C(O)N(H)S– skeleton. Experimental and calculated data allow to trace this structural feature to the occurrence of N–H⋯On bonding interactions. Calculated vibrational and structural properties are in good agreement with the experimentally determined features. [Copyright &y& Elsevier]

Abstract: Reaction of VOCl2 with 2-pyridineformamide thiosemicarbazone (H2Am4DH) and its N(4)-methyl (H2Am4Me), N(4)-ethyl (H2Am4Et) and N(4)-phenyl (H2Am4Ph) derivatives in ethanol gave as products [VO(H2Am4DH)Cl2] (1), [VO(H2Am4Me)Cl2]·1/2HCl (2), [VO(H2Am4Et)Cl2]·HCl (3) and [VO(2Am4Ph)Cl] (4). Upon the dissolution of 1–4 in water, oxidation immediately occurs with the formation of [VO2(2Am4DH)] (5), [VO2(2Am4Me)] (6), [VO2(2Am4Et)] (7) and [VO2(2Am4Ph)] (8). The crystal and molecular structures of 5 and 6 were determined. Complexes 5–8 inhibited glycerol release in a similar way to that observed with insulin but showed a low enhancing effect on glucose uptake by rat adipocytes. [Copyright &y& Elsevier]

Abstract: Novel rhenium complexes containing the maltolate (mal) or kojate (koj) anions as chelating ligands have been synthesized: [ReOCl(mal)2] (1), [ReOCl2(mal)(PPh3)] (2), [ReOBr2(mal)(PPh3)] (3), [ReOCl2(koj)(PPh3)] (4) and [ReOBr2(koj)(PPh3)] (5). The products have been characterized by FTIR, 1H, 13C, and 31P NMR spectroscopies and elemental analysis. The crystal and molecular structures of all complexes were determined. Complex 1 crystallizes monoclinic, space group C2/c, Z =8. It contains two O,O′-bidentate maltolate ligands and one chloro ligand at the (ReO)3+ unit, so that a distorted octahedral geometry is adopted by the six-coordinated rhenium(V) center. The chloro ligand occupies a cis position to the oxo ligand. Complexes 2 and 3 are isostructural and crystallize orthorhombic, space group Pbca and Z =8. The isostructural complexes 4 and 5 crystallize monoclinic, space group P21/n and Z =4. In complexes 2–5, the (ReO)3+ unit is coordinated by a monoanionic O,O-bidentate unit of the maltolate (2 and 3) or kojate (4 and 5) ligand, one triphenylphosphine and two halogeno ligands (Cl in 2 and 4; Br in 3 and 5), with the rhenium(V) center in a distorted octahedral environment. The halide ligands are in cis positions to each other. [Copyright &y& Elsevier]

Abstract: Two Cu(II) complexes with cyanoguanidine (cnge) and o-phenanthroline, [Cu(o-phen)2(cnge)](NO3)2 ·2H2O (1) and [Cu(o-phen)(cnge)(H2O)(NO3)2] (2), have been synthesized using different experimental techniques and characterized by elemental analyses, FTIR, diffuse and UV–vis spectra and EPR and magnetic moment measurements techniques. The crystal structures of both complexes were solved by X-ray diffraction methods. Complex (1) crystallizes in the monoclinic space group C2/c with a =12.621(5), b =31.968(3), c =15.39(1)Å, β =111.68(4)°, and Z =8 and complex (2) in the monoclinic space group P21/n with a =10.245(1), b =13.923(2), c =12.391(2)Å, β =98.07(1)°, and Z =4. The environments of the copper(II) center are trigonal bipyramidal (TBP) for [Cu(o-phen)2(cnge)]2+ and an elongated octahedron for [Cu(o-phen)(cnge)(H2O)(NO3)2]. Solution studies have been performed to determine the species distribution. The superoxide dismutase (SOD) activities of both complexes have also been tested in order to determine if these compounds mimic the enzymatic action of the enzyme SOD that protects cells against peroxide radicals. [Copyright &y& Elsevier]

Abstract: The molecular structure of the title complex, [Cu(C6H14N4O2)2(H2O)]CO3 ·H2O, was determined by single crystal X-ray diffractometry. It crystallizes in the monoclinic space group P21, with Z =2. The Cu(II) ion is in a square pyramidal environment, trans coordinated at the basis by two argininate groups acting as bidentate ligands through their amino nitrogen and carboxylate oxygen atoms. The coordination around copper is completed by a water molecule at the pyramid apex. The infrared, Raman and electronic spectra are briefly discussed on the basis of the structural peculiarities of the complex. [Copyright &y& Elsevier]

The molecular structure of [Cu(sulfadimet)2]·SO(CH3)2 (sulfadimet=sulfadimethoxine=4-p-aminobenzenesulfonamido-2,6-dimethoxypyrimidine) was determined by single crystal X-ray diffractometry. It crystallizes in the monoclinic space group P21/c with Z=4. The Cu(II) cation is in a distorted CuN5 square pyramidal coordination, involving four sulfadimethoxine molecules, one of them acting as a bidentate ligand. The infrared spectrum is briefly discussed on the basis of the structural peculiarities of the complex. [Copyright &y& Elsevier]