XANES studies of monosubstituted benzhydrazide complexes of copper

Abstract

K x-ray absorption near-edge structure (XANES) studies were carried out on nine samples of monosubstituted benzhydrazide complexes of copper, viz. copper(II) benzhydrazide, o-, m-and phydroxybenzhydrazide, o-, m-and p-nitrobenzhydrazide and o-and p-chlorobenzhydrazide. These complexes are known for their pharmacological activity as antitubercular agents, antibacterial agents and as fungicides. In the three categories of substituted benzhydrazides the ionicity is found to increase in the order para > meta > ortho. Our studies revealed that the substituted complexes are less ionic than the parent complex. Among the three groups, hydroxy-substituted complexes are more ionic than nitro-and chloro-substituted hydrazides. Splitting of the principal absorption maximum .1s → 4p/ takes place in most of these complexes. The splitting into two components has been assigned to the transitions 1s → A * (4p z ) and 1s → B * (4p x , 4p y ). The estimated bandgap values for these complexes decrease in the order ortho > meta > para. The present studies indicate that as the chemical shift values increase in all the three groups, the bandgap energy values decrease.

Atomic spectrometry update. Atomic mass spectrometry

“…A new procedure for determination of the d 15 N of total dissolved nitrogen used a commercial total organic carbon (TOC) analyser coupled to an EA-SIRMS instrument. 214 Nitrogen compounds were converted to NO and NO 2 by high-temperature catalytic oxidation prior to isotope analysis. An important change to previous systems was that the flow paths were modified so that both the TOC and SIRMS analysers could be run with He as carrier gas while maintaining complete sample oxidation.…”

Polymeric and mixed ligand complex of cobalt(II) and 4-hydroxybenzhydrazide: Crystal structure and vibrational spectroscopy

“…The research has been mainly focused on the copper(II) [6][7][8][9][10][11][12][13][14] and nickel(II) [6,7,11,14] complexes. Only two communications have taken into account the 4hbah complexes with dithionate cobalt salts [7,14].…”