Synthesis, characterization and anti-microbial evaluation of Cu(II), Ni(II), Pt(II) and Pd(II) sulfonylhydrazone complexes; 2D-QSAR analysis of Ni(II) complexes of sulfonylhydrazone derivatives.

Copper(II), nickel(II), platinum(II) and palladium(II) complexes with 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) derived from propanesulfonic acid-1-methylhydrazide (psmh) were synthesized, their structure were identified, and antimicrobial activity of the compounds was screened against three Gram-positive and three Gram-negative bacteria. The results of antimicrobial studies indicate that Pt(II) and Pd(II) complexes showed the most activity against all bacteria. The crystal structure of 2-hydroxy-1-naphthaldehyde-N-methylpropanesulfonylhydrazone (nafpsmh) was also investigated by X-ray analysis. A series of Ni(II) sulfonyl hydrazone complexes (1-33) was synthesized and tested in vitro against Escherichia coli and Staphylococcus aureus. Their antimicrobial activities were used in the QSAR analysis. Four-parameter QSAR models revealed that nucleophilic reaction index for Ni and O atoms, and HOMO-LUMO energy gap play key roles in the antimicrobial activity.

Conformational analysis, vibrational and NMR spectroscopic study of the methanesulfonamide-N,N'-1,2-ethanediylbis.

A conformational analysis of the methanesulfonamide-N,N'-1,2-ethanediylbis (msen) was performed by using vibrational and NMR spectroscopies as well as theoretical computations. The possible stable conformers of msen on its potential energy surface were investigated by semi-empirical PM5 method and appropriate structures were defined with B3LYP hybrid density functional theory (DFT) method along with the basis sets of different size and type. Six different rotational isomers were found as the result of DFT calculation. The two isomer, called trans-trans-gauche(+)-eclipsed, synperiplanar (ttg(+)-e,bis) and trans-gauche(+)-gauche(-)-staggered, antiplanar (tg(+)g(-)-s,anti), were considered in the vibrational spectral analysis. The infrared (4000-30 cm(-1)) and Raman (4000-60 cm(-1)) spectra of msen were measured in solid state. For a complete assignment of the vibrational spectra, DFT calculations at B3LYP/6311-G(d,p) theory level combined with scaled quantum mechanics force field (SQMFF) methodology was performed. Furthermore, (13)C and (1)H NMR analyses were performed for six conformers at B3LYP/6-311++G(d,p) level of theory and compared with the experimental findings. Results from experimental and theoretical data showed the ttg(+)-e,bis to be the most stable form of a msen molecule.