title: Pyridazine-based Schiff base ligands with N4OxS2 (x=2, 4) donor set atoms: synthesis, characterization, spectral studies and 13C chemical shifts computed by the GIAO-DFT and CSGT-DFT methodologies.
abstract: Six pyridazine-based Schiff base ligands, H(2)L(n) (n=1-5) and H(4)L, with N(4)O(2)S(2) and N(4)O(4)S(2) donor set atoms, respectively, were prepared by condensation reaction of 3,6-bis-((2-aminoethyl)thio)pyridazine with various salicyladehyde derivatives in ethanol and under solvent-free polyphosphate ester catalyzed conditions. The acid-base properties of H(2)L(2) and H(2)L(3) in DMSO/water (1:1) solution have been studied by spectrophotometric method at 25 degrees C. Optimized geometries of all compounds were also obtained at the B3LYP level of theory. Additionally, the (13)C chemical shielding of gas phase H(2)L(1) and H(2)L(2) were studied by the gauge independent atomic orbital (GIAO) and continuous set of gauge transformations (CSGT) methods at the level of density functional theory (DFT). The 6-311++G* basis set was utilized for all of the atoms.
authors.affiliation: Department of Chemistry, Arak University, Arak, Iran. h-khanmohammadi@araku.ac.ir
authors.forename: Hamid
authors.initials: H
authors.lastname: Khanmohammadi
authors.forename: Malihe
authors.initials: M
authors.lastname: Erfantalab
mesh_terms: D004563:Electrochemistry / Q000379:methods; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000295:instrumentation / Q000379:methods*; D011724:Pyridazines / Q000138:chemical synthesis / Q000737:chemistry*; D012545:Schiff Bases / Q000138:chemical synthesis / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000379:methods*
chemical_list: D008024:Ligands; D011724:Pyridazines; D012545:Schiff Bases; D012997:Solvents; C062482:pyridazine