2-[(1E)-({[(Benzylsulfanyl)methanethioyl]amino}- imino)methyl]-6-methoxyphenol: crystal structure and Hirshfeld surface analysis

The title di­thio­carbazate ester, C16H16N2O2S2, comprises two almost planar residues, i.e. the phenyl ring and the remaining 14 non-H atoms (r.m.s. deviation = 0.0410 Å). These are orientated perpendicularly, forming a dihedral angle of 82.72 (5)°. An intra­molecular hy­droxy-O—H⋯N(imine) hydrogen bond, leading to an S(6) loop, is noted. An analysis of the geometric parameters is consistent with the mol­ecule existing as the thione tautomer, and the conformation about the C=N bond is E. The thione S and imine H atoms lie to the same side of the mol­ecule, facilitating the formation of inter­molecular N—H⋯S hydrogen bonds leading to eight-membered {⋯HNCS}2 synthons in the crystal. These aggregates are connected by phenyl-C—H⋯O(hy­droxy) inter­actions into a supra­molecular layer in the bc plane; these stack with no directional inter­actions between them. An analysis of the Hirshfeld surface confirms the nature of the inter­molecular inter­actions

A three-electrode integrated photo-supercapacitor utilizing graphene-based intermediate bifunctional electrode

A dye-sensitized solar cell (DSSC) employing a compact and mesoporous titania (TiO2) film as the anode was integrated with a symmetrical supercapacitor utilizing polypyrrole/reduced graphene oxide (PPy/rGO) electrodes to form a photo-supercapacitor. The double-sided-electrodeposited PPy/rGO material served as an intermediate electrode which was bifunctional in nature; acting as a counter electrode for the DSSC to permit electrolyte regeneration, and also as an electrode for the supercapacitor. The isolated DSSC and supercapacitor were characterized before the integration, and the power conversion efficiency (PCE) of the DSSC was 2.4%, while the specific capacitance of the supercapacitor was 308.1 F/g. The performance of the integrated photo-supercapacitor was tested under a light illumination of 100 mW/cm2. By using a single PPy/rGO electrode at the cell/supercapacitor interface, an extended lifetime was achieved with up to 50 charge/discharge cycles. The photo-supercapacitor possessed a specific capacitance of 124.7 F g−1, and a retention percentage of 70.9% was obtained after 50 consecutive charge/discharge cycles

Bis{N′-[3-(4-nitrophenyl)-1-phenylprop-2-en-1-ylidene]-N-phenylcarbamimidothioato}zinc(II): crystal structure, Hirshfeld surface analysis and computational study

The title zinc bis­(thio­semicarbazone) complex, [Zn(C22H17N4O2S)2], comprises two N,S-donor anions, leading to a distorted tetra­hedral N2S2 donor set. The resultant five-membered chelate rings are nearly planar and form a dihedral angle of 73.28 (3)°. The configurations about the endocyclic- and exocyclic-imine bonds are Z and E, respectively, and that about the ethyl­ene bond is E. The major differences in the conformations of the ligands are seen in the dihedral angles between the chelate ring and nitro­benzene rings [40.48 (6) cf. 13.18 (4)°] and the N-bound phenyl and nitro­benzene ring [43.23 (8) and 22.64 (4)°]. In the crystal, a linear supra­molecular chain along the b-axis direction features amine-N—H...O(nitro) hydrogen bonding. The chains assemble along the 21-screw axis through a combination of phenyl-C—H...O(nitro) and π(chelate ring)–π(phen­yl) contacts. The double chains are linked into a three-dimensional architecture through phenyl-C—H...O(nitro) and nitro-O...π(phen­yl) inter­actions

Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: synthesis, X-ray crystallography and biological activity

Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines

Homoleptic tin(IV) compounds containing tridentate ONS dithiocarbazate Schiff bases: Synthesis, X-ray crystallography, DFT and cytotoxicity studies

Six new tin(IV) compounds derived from tridentate dinegatively charged ONS dithiocarbazate Schiff bases derived from 2-hydroxy-3-methoxybenzaldehyde (H2L1, H2L2 and H2L3) and 2,3-dihydroxybenzaldehyde (H2L4, H2L5 and H2L6) (where H2Ln = di-acids of Schiff base) are reported. The compounds were characterised by elemental analysis, FT-IR and multinuclear NMR (1H, 13C and 119Sn) spectroscopy. The crystal structures of tin(IV) [S-4-methybenzyl-β-N-(2-hydroxy-3-methoxybenzylmethylene)dithiocarbazate] (2) and tin(IV) [S-benzyl-β-N-(2-hydroxy-3-methoxy benzylmethylene)dithiocarbazate] (3) were determined by X-ray single crystal diffraction analysis. X-ray crystallography showed the molecular geometries in homoleptic 2 and 3 to be quite similar in which the dinegative tridentate ligand coordinated the tin atoms via thiolate-S, phenoxide-O and imine-N atoms. The coordination geometries are based on an octahedron with like-atoms mutually trans. The experimental findings were validated by density functional theory (DFT) calculations at the B3LYP/LanL2DZ/6-311G(d,p) level of theory. All the tin(IV) compounds, except the insoluble compound 2 were screened for their in vitro cytotoxicity against a panel ten of cancer cell lines and one normal breast cell line (MCF-10 A) by MTT assay. Interestingly, the cytotoxicity of five tin(IV) compounds against HT29, MCF7 and MIA was higher than the reference drug, cisplatin

Synthetic, spectroscopic and X-ray crystallographic structural study of the monomeric [Cu(pysme)(sac)(MeOH)] and dimeric [Cu(6mptsc)(sac)](2) complexes [pysme = anion of the pyridine-2-carboxaldehyde Schiff base of S-methyldithiocarbazate, 6mptsc=the anio

New mixed-ligand copper(II) complexes of empirical formulas [Cu(pysme)(sac) (CH3OH)] and [Cu(6mptsc)(sac)](2) have been synthesized and characterized by conductance, magnetic, IR and electronic spectroscopic techniques. X-ray crystallographic structure analyses of these complexes indicate that in both complexes the copper(II) ions adopt a five-coordinate distorted square-pyramidal geometry with an N3SO donor environment. The Schiff bases are coordinated to the copper(II) ions as tridentate NNS chelates via the pyridine nitrogen atom, the azomethine nitrogen atom and the thiolate sulfur atom. In the monomeric [Cu(pysme)(sac)(MeOH)] complex, the saccharinate anion acts as a monodentate ligand coordinating the copper(II) ion via the imino nitrogen atom whereas in the dimeric [Cu(6mptsc)(sac)](2) complex, the sac anion behaves as a bridging bidentate ligand providing the imino nitrogen donor atom to one of the copper(II) ions and the carbonyl oxygen as a weakly coordinated axial ligand atom to the other Cu(II) ion. In both complexes, the copper(II) ions have distorted square-pyramidal environments. The distortion from an ideal square-pyramidal geometry is attributed to the restricted bite angles of the planar tridentate ligand. (C) 2004 Elsevier Ltd. All rights reserved

Synthesis, characterization and biological studies of S-4-methylbenzyl-β-N-(2-furylmethylene)dithiocarbazate (S4MFuH) its Zn2+, Cu2+, Cd2+ and Ni2+ complexes

S-4-methylbenzyl-β-N-(2-furylmethylene)dithiocarbazate (S4MFuH, 1) derived from the condensation reaction of furaldehyde (Fu) with S-4-methylbenzyldithiocarbazate (S4MBDTC) has been complexed with transition metal acetates to give Zn(S4MFu)2 (2), Cd(S4MFu)2 (3), Cu(S4MFu)2 (4) and Ni(S4MFu)2 (5). It is evident from the shift in ν(CN) and ν(NN) in the IR spectra of the complexes that deprotonated 1 acts as a bidentate ligand coordinating through the azomethine nitrogen and thiolato sulfur atoms. This was confirmed by single crystal X-ray diffractometry. The U-shaped dithiocarbazate 1 exists in the E configuration with the thione bond anti to the azo bond. A change in conformation is noted in the transition metal complexes resulting from deprotonation and NS-chelation. 2 and 3 display a distorted tetrahedral geometry with the major cause of the distortion being two close intramolecular M…O interactions. Binding interaction studies with calf thymus DNA demonstrated that 4 also had the strongest DNA binding affinity (Kb=2.85×104M−1) among all compounds prepared in this work. The Cu(II) complex, 4, was also moderately active against estrogen receptor-positive breast cancer cells, MCF-7 (IC50=3.02μM) while the remainder were inactive against MCF-7 and all showed no activity towards receptor negative breast cancer cells, MDA-MB-231

<i>o</i>-Vanillin Derived Schiff Bases and Their Organotin(IV) Compounds: Synthesis, Structural Characterisation, In-Silico Studies and Cytotoxicity

Six new organotin(IV) compounds of Schiff bases derived from S-R-dithiocarbazate [R = benzyl (B), 2- or 4-methylbenzyl (2M and 4M, respectively)] condensed with 2-hydroxy-3-methoxybenzaldehyde (oVa) were synthesised and characterised by elemental analysis, various spectroscopic techniques including infrared, UV-vis, multinuclear (1H, 13C, 119Sn) NMR and mass spectrometry, and single crystal X-ray diffraction. The organotin(IV) compounds were synthesised from the reaction of Ph2SnCl2 or Me2SnCl2 with the Schiff bases (S2MoVaH/S4MoVaH/SBoVaH) to form a total of six new organotin(IV) compounds that had a general formula of [R2Sn(L)] (where L = Schiff base; R = Ph or Me). The molecular geometries of Me2Sn(S2MoVa), Me2Sn(S4MoVa) and Me2Sn(SBoVa) were established by X-ray crystallography and verified using density functional theory calculations. Interestingly, each experimental structure contained two independent but chemically similar molecules in the crystallographic asymmetric unit. The coordination geometry for each molecule was defined by thiolate-sulphur, phenoxide-oxygen and imine-nitrogen atoms derived from a dinegative, tridentate dithiocarbazate ligand with the remaining positions occupied by the methyl-carbon atoms of the organo groups. In each case, the resulting five-coordinate C2NOS geometry was almost exactly intermediate between ideal trigonal-bipyramidal and square-pyramidal geometries. The cytotoxic activities of the Schiff bases and organotin(IV) compounds were investigated against EJ-28 and RT-112 (bladder), HT29 (colon), U87 and SJ-G2 (glioblastoma), MCF-7 (breast) A2780 (ovarian), H460 (lung), A431 (skin), DU145 (prostate), BE2-C (neuroblastoma) and MIA (pancreatic) cancer cell lines and one normal breast cell line (MCF-10A). Diphenyltin(IV) compounds exhibited greater potency than either the Schiff bases or the respective dimethyltin(IV) compounds. Mechanistic studies on the action of these compounds against bladder cancer cells revealed that they induced the production of reactive oxygen species (ROS). The bladder cancer cells were apoptotic after 24 h post-treatment with the diphenyltin(IV) compounds. The interactions of the organotin(IV) compounds with calf thymus DNA (CT-DNA) were experimentally explored using UV-vis absorption spectroscopy. This study revealed that the organotin(IV) compounds have strong DNA binding affinity, verified via molecular docking simulations, which suggests that these organotin(IV) compounds interact with DNA via groove-binding interactions

Selective cytotoxicity of organotin(IV) compounds with 2,3-dihydroxybenzyldithiocarbazate Schiff bases

A series of tridentate ONS Schiff bases were synthesised via condensation by reacting 2,3-dihydroxybenzaldehyde with S-2-methylbenzyldithiocarbazate (S2MBDTC) (1), S-4-methylbenzyldithiocarbazate (S4MBDTC) (2) and S-benzyldithiocarbazate (SBDTC) (3) in an equimolar ratio (10 mmol). The Schiff bases were then reacted with diphenyltin(IV) and dimethyltin(IV) dichloride in an equimolar ratio (1 mmol) yielding six new organotin(IV) compounds (4–9). All the compounds were successfully characterised by elemental analysis, FT-IR, multinuclear NMR, UV–Vis, mass spectroscopy and molar conductivity. The molecular geometries for five compounds, 3, 5, 6, 8 and 9, have been established by X-ray crystallography. The five-coordinate geometry for each of the diorganotin molecules was defined by two carbon atoms from the tin-bound substituents as well as three donor atoms derived from the dinegative, tridentate dithiocarbazate ligands, namely thiolate-S, phenoxide-O and imine-N atoms. The resultant five-coordinate C2NOS geometries were intermediate between ideal square pyramidal and trigonal bipyramidal geometries. The diphenyltin(IV) compounds (4–6) exhibited particularly promising and selective cytotoxicity against the A2780 (ovarian), BE2-C (neuroblastoma), SJ-G2 (glioblastoma) and MIA (pancreas) cancer cell lines. The interactions of the compounds (4–9) with calf thymus (CT-DNA) were evaluated using an electronic absorption method, and 7, 8, 9 were found to have good DNA binding affinity. The molecular docking studies of compounds (4–9) with DNA revealed that the compounds interacted with duplex DNA via hydrogen bonding, hydrophobic and electrostatic interactions