Synthesis of Triphenyltin (IV) and Dibutyltin (IV) Complexes of 1-Aryl-2,5-dithiohydrazodicarbonamides and Their Characterization

Organotin complexes of the types Ph3SnL and Bu2SnL [where Ph = phenyl and Bu = butyl; HL = 1-phenyl-2,5-dithiohydrazodicarbonamide (HPhthc), 1-benzyl-2,5-dithiohydrazodicarbonamide (Hbzthc), 1-(4-ethoxyphenyl)-2,5-dithiohydrazodicarbonamide (HEtOPhthc)] have been prepared. Molar conductance studies demonstrate the nonionic behavior of the complexes. The 1H and 13C nuclear magnetic resonance and FAB mass spectra of the complexes are consistent with the proposed stoichiometry. Infrared spectra suggest an anionic bidentate coordinating behavior of the ligands.

Nucleophilic Aromatic Substitution with 2,3-Dihydro-1,3-diisopropyl- 4,5-dimethylimidazol-2-ylidene

2,3-Dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (1) reacts with an excess of hexafluorobenzene in the presence of boron trifluoride diethyletherate to give 1,3-diisopropyl-4,5- dimethyl-2-(perfluorophenyl)imidazolium tetrafluoroborate (2). Solutions of 2 exhibit an equilibrium consisting also of hexafluorobenzene and 2,2ʹ-(perfluoro-1,4-phenylene)bis(1,3-diisopropyl- 4,5-dimethylimidazolium)bis(tetrafluoroborate) (3) which is obtained from 1 and hexafluorobenzene in the ratio 2 : 1 on a preparative scale. Similar to 2, 2-(4-cyano-2,3,5,6-tetrafluorophenyl)-1,3- diisopropyl-4,5-dimethylimidazolium tetrafluoroborate (4), 2-(2,4-dicyano-2,5,6-trifluorophenyl)- 1,3-diisopropyl-4,5-dimethylimidazolium tetrafluoroborate (5), and 2-(4,6-difluoro-1,3,5-triazin-2- yl)-1,3-diisopropyl-4,5-dimethylimidazolium tetrafluoroborate (6) are obtained from 1 and perfluorobenzonitrile, 1,3-dicyano-2,4,5,6-tetrafluorobenzene, and 2,4,6-trifluoro-1,3,5-triazin, respectively. The FAB mass spectra of compounds 2 - 6 and the results of the crystal structure analyses of compounds 2 - 4 are discussed.

Synthesis, Spectroscopic, and Antimicrobial Studies of Binuclear Metallocene (M = Ti, Zr, or Hf) Derivatives of Bis(mercaptoazoles)

The reactions of(η5−C5H5)2MCl2(M = Ti, Zr, or Hf) with mercaptoazoles(LH2), namely, bis(mercaptotriazoles), bis(mercap-tooxadiazoles), and bis(mercaptothiadiazoles) in 2 : 1 molar ratio, respectively, have been studied in dry tetrahydrofuran in the presence ofn-butylamine and the binuclear complexes of the type[{(η−C5H5)2M}2(L)](M = Ti/Zr/Hf) are obtained. Tentative structural conclusions are drawn for the reaction products based upon elemental analysis, electrical conductance, magnetic moment, and spectral data (UV-Vis, IR,H1NMR, andC13NMR). FAB-mass spectra of few complexes of each series were also carried out to confirm the binuclear structures. Studies were conducted to assess the growth-inhibiting potential of the complexes synthesized, and the ligands against various fungal and bacterial strains.

Synthetic, structural and antifungal studies of coordination compounds of Ru(III), Rh(III) and Ir(III) with tetradentate schiff bases

A series of octahedral Ru(III), Rh(III) and Ir(III) complexes have been prepared with tetradentate Schiff bases derived by condensing isatin with 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,2-diaminobenzene and 1,3-diaminobenzene. The obtained complexes were characterized on the basis of their elemental analyses, magnetic moment, conductance, IR electronic, 1HNMR and FAB mass spectra, as well as thermal analyses. The Ru(III) complexes are low spin paramagnetic, while Rh(III) and Ir(III) behave as diamagnetic complexes. The IR spectral data revealed that all the Schiff bases behave as tetradentate and are coordinated to Ru(III), Rh(III) and Ir(III) via nitrogen and oxygen. Antifungal studies of the ligands as well as their complexes were carried out by the agar plate method.