Bis[benzylN′-(3-phenylprop-2-enylidene)dithiocarbazato-κ2N′,S]mercury(II)

In the title compound, [Hg(C₁₇H₁₅N₂S₂)₂], the Hg^II ion lies on a crystallographic twofold rotation axis giving a very distorted tetra­hedral coordination geometry best described as bis­phenoidal, being chelated by two deprotonated N,S Schiff base ligands through the azomethine nitro­gen and the thiol­ate sulfur donors. The dihedral angle between the two chelating ligand moieties is 79.75 (10)°. In the crystal, weak C—H⋯S inter­actions give rise to chains extending along the c axis.

Bis[benzyl 3-(3-phenyl-prop-2-enyl-idene)dithio-carbazato-κ(2)N(3),S]cadmium

In the title complex, [Cd(C₁₇H₁₅N₂S₂)₂], the Cd^II ion is located on a twofold rotation axis and exhibits a coordination number of four within a very distorted coordination environment that is best described as bis­phenoidal. The two deprotonated Schiff base ligands chelate the Cd^II ion through the azomethine N and the thiol­ate S atom. The dihedral angle between the two chelating ligands is 84.01 (9)°. Weak inter­molecular C—H⋯S inter­actions lead to the formation of chains along the c axis.

Methyl 3-[(E,E)-3-phenyl-prop-2-enyl-idene]dithio-carbazate

In the title compound, C₁₁H₁₂N₂S₂, the dithio­carbazate group adopts an EE configuration with respect to the C=C and C=N bonds of the propenyl­idene group. The atoms of the propenyl­idene and dithio­carbazate unit are essentially co-planar, with a maximum deviation of 0.058 (1) Å; the phenyl ring forms a dihedral angle of 18.3 (1)° with this fragment. In the crystal, mol­ecules form inversion dimers via pairs of N—H⋯S hydrogen bonds involving the terminal S atom.

(E)-4-Octyloxybenzaldehyde thio-semicarbazone

In the title compound, C(16)H(25)N(3)OS, the thio-semicarbazone group adopts an E configuration with respect to the C=N bond and is almost coplanar with the benzene ring, forming a dihedral angle of 9.3 (1)°. In the crystal packing, the mol-ecules lie along the a axis in an anti-parallel arrangement and are held in place by van der Waals inter-actions. As a consequence, there is relatively low anisotropic thermal motion in the terminal atoms of the n-octyl chain.

2,4-Dimethoxy-benzaldehyde azine

The title mol­ecule, C₁₈H₂₀N₂O₄, is located on a crystallographic centre of symmetry. The meth­oxy groups are coplanar with the benzene ring [interplanar angles of 14.4 (2) and 3.1 (3)°], indicating a conjugation effect.

Di-μ-methacrylato-κO:O'-bis-[aqua-bis(1,10-phenanthroline-κN,N')copper(II)] dinitrate dihydrate

The title complex, [Cu₂(C₄H₅O₂)₂(C₁₂H₈N₂)₂(H₂O)₂](NO₃)₂·2H₂O, contains a dimeric [Cu₂(C₄H₅O₂)₂(C₁₂H₈N₂)₂(H₂O)₂]²⁺ dication with two five-coordinated Cu^II ions linked by two methacrylate ions in a syn–syn bridging arrangement. The dication possesses pseudo-twofold rotational symmetry. The penta­coordination of each Cu^II ion has a distorted square-pyramidal geometry, with two N donors from a phenanthroline ligand and two carboxyl­ate O atoms occupying basal sites and the apical position being occupied by a water mol­ecule. In the crystal packing, mol­ecules are linked to form a three-dimensional framework by O—H⋯O and C—H⋯O hydrogen bonds and π–π inter­actions [centroid–centroid distances of 3.6039 (15), 3.5301 (15), 3.6015 (15), 3.6496 (15) and 3.6858 (15) Å].

Benzyl 3-[(E,E)-3-phenyl-prop-2-enyl-idene]dithio-carbazate

The title compound, C₁₇H₁₆N₂S₂, a dithio­carbazate derivative, adopts an EE configuration with respect to the C=C and C=N double bonds of the propenyl­idine group. The 3-phenyl­prop-2-enyl­idene and dithio­carbazate fragments lie essentially in the same plane, with a maximum deviation from that plane of 0.074 (2) Å, while the dihedral angle between the 3-phenyl­prop-2-enyl­idene and the benzyl group is 77.78 (7)°. In the crystal structure, mol­ecules are linked by an N—H⋯S hydrogen bond and a weak C—H⋯S inter­action involving the terminal thione S atom, forming dimers that are arranged into sheets parallel to the bc plane. The crystal structure is also stabilized by C—H⋯π inter­actions.

(E)-4-(Benz-yloxy)benzaldehyde thio-semicarbazone

In the title compound, C(15)H(15)N(3)OS, the thio-semicarbazone group adopts an E configuration with respect to the C=N bond. The benzaldehyde thio-semicarbazone fragment is almost planar [maximum deviation = 0.012 (1) Å], while the dihedral angle between the benz-yloxy and phenyl rings is 72.48 (5)°. In the crystal structure, mol-ecules are inter-connected by N-H⋯N and N-H⋯S hydrogen bonds, forming a two-dimensional network parallel to the bc plane and are further stacked along the a axis by π-π inter-actions [centroid-centroid separation 3.9043 (7) Å]. The crystal structure is also stabilized by C-H⋯π inter-actions.

Bis[benzylN′-(3-phenylprop-2-enylidene)hydrazinecarbodithioato-κ2N′,S]zinc(II)

In the title Zn^II complex, [Zn(C₁₇H₁₅N₂S₂)₂], the Zn^II atom lies on a twofold rotation axis. It exists in a tetra­hedral geometry, chelated by two deprotonated Schiff base ligands. The dihedral angle between each ligand is 71.48 (8)°. Mol­ecules are connected by weak C—H⋯S inter­molecular inter­actions into chains along the c axis. The crystal structure is further stabilized by C—H⋯π inter­actions involving the phenyl ring of the 3-phenyl­prop-2-enyl­idene unit.

Bis[benzyl N'-(3-phenyl-prop-2-enyl-idene)hydrazinecarbodithio-ato-κN',S]copper(II)

The Cu^II atom of the title complex, [Cu(C₁₇H₁₅N₂S₂)₂], lies on a twofold rotation axis, and is in a distorted tetra­hedral geometry with the two bidentate N₂S₂ Schiff bases. In the crystal structure, the mol­ecules are inter­connected into chains along the c axis by weak C—H⋯S inter­molecular inter­actions. The crystal packing is further stabilized by C—H⋯π inter­actions.

Biological activity of palladium(II) and platinum(II) complexes of the acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate and the X-ray crystal structure of the [Pd(asme)2] (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) complex

Palladium(II) and platinum(II) complexes of general empirical formula, [M(NS)(2)] (NS=uninegatively charged acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate; M=Pt(II) and Pd(II)) have been prepared and characterized by a variety of physicochemical techniques. Based on conductance, IR and electronic spectral evidence, a square-planar structure is assigned to these complexes. The crystal and molecular structure of the [Pd(asme)(2)] complex (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) has been determined by X-ray diffraction. The complex has a distorted cis-square planar structure with the ligands coordinated to the palladium(II) ions as uninegatively charged bidentate NS chelating agents via the azomethine nitrogen and the mercaptide sulfur atoms. The distortion from a regular square-planar geometry is attributed to the restricted bite angles of the ligands. Antimicrobial tests indicate that the Schiff bases exhibit strong activities against the pathogenic bacteria, Bacillus subtilis (mutant defective DNA repair), methicillin-resistant Staphylococcus aureus, B. subtilis (wild type) and Pseudomonas aeruginosa and the fungi, Candida albicans (CA), Candida lypotica (2075), Saccharomyces cerevisiae (20341) and Aspergillus ochraceous (398)-the activities exhibited by these compounds being greater than that of the standard antibacterial and antifungal drugs, streptomycin and nystatin, respectively. The palladium(II) and platinum(II) complexes are inactive against most of these organisms but, the microbe, Pseudomonas aeruginosa shows strong sensitivity to the platinum(II) complexes. Screening of the compounds for their cytotoxicities against T-lymphoblastic leukemia cancer cells has shown that the acetone Schiff base of S-methyldithiocarbazate (Hasme) exhibits a very weak activity, whereas the S-benzyl derivative (Hasbz) is inactive. However, the palladium(II) complexes exhibit strong cytotoxicities against this cancer; their activities being more than that of the standard anticancer drug, tamoxifen. The [Pt(asme)(2)] complex exhibits a very weak cytotoxicity, whereas [Pt(asbz)(2)] is inactive against leukemic cells.

The nature of bonding in hexahalothorates and hexahalouranates(IV)

Enthalpies of reaction have been determined by solution calorimetry for the process 2AX(c) + ThX4(c) = A2ThX6(c) where A = K, Cs and X = Cl, Br. The measurements afforded the following values of standard enthalpies of formation [Formula: see text], in kJ mol−1: K2ThCl6, −2108; Cs2ThCl6, −2151; K2ThBr,−1774; Cs2ThBr6,−1826. The standard enthalpies of formation of ThCl62− (g), ThBr62− (g), UCl62− (g), and UBr62− (g) and the two-halide ion affinities of ThCl4, ThBr4, UCl4, and UBr4 were compared by assuming semi-empirical (Kapustinskii) values of the lattice energies of the complexes. Homolytic and heterolytic bond energies were also calculated.

Chelates of nickel(II) and copper(II) with tridentate Schiff base formed by the condensation of S-benzyldithiocarbazate with benzoin

New complexes with the Schiff base ligand derived from S-benzyldithiocarbazate (NH2—NH—CSSCH2C6H5) have been prepared and characterized by elemental analyses, magnetic, conductometric, ir, and electronic spectral studies. The tridentate ONS Schiff base S-benzyl-β-N-(phenyl, phenylhydroxymethyl)methylenedithiocarbazate gave mono-ligand complexes with Ni(II) and Cu(II) having the general formula [MligandX] (M = Ni(II) and Cu(II); X = NO3, Cl, Br, NCS). A proposed square-planar structure for the nickel complexes is supported by magnetic and spectral data. A square-planar structure is also suggested for Cu(II) complexes. The ir results give evidence of the different bondings present in the complexes.