Photoacoustic Spectral Studies Research Articles

Listening to Chemical Materials: Determination of the Photophysical Parameters by Photoacoustic Spectroscopy

Recently, photoacoustic (PA) spectroscopy has emerged as a valuable tool for the study of various kinds of materials. Herein, we present the results of PA spectral studies of chemical materials. First, the PA study on luminescent materials in condensed states is reported. Combining with the luminescence technique, the energy transfer efficiency and the intrinsic luminescence quantum yield are determined for a europium (III) complex in the glassy state, smectic A phase, and the isotropic liquid. Second, neodymium (III) compounds with l-glycine, l-phenylalanine, and l-tryptophan are synthesized and their PA spectra are reported. The nephelauxetic ratio and Sinha parameter are calculated based on the PA spectra. The environmental effect on the f–f transitions of the neodymium(III) ion is also studied.

Distortion of the coordination polyhedron in mononuclear copper(II) complexes. Optical absorption and electron spin resonance studies on some five-coordinate copper(II) complexes

The preparation and spectral properties are reported for a series of ten mixed-ligand copper(II) complexes of the form [Cu( A)( B) n ]( X), where A is acetylacetonate anion, B represents a mono- or bidentate ligand such as morpholine, piperidine, isonicotinic acid hydrazide, 2,2′-bipyridine, 1,10-phenanthroline and X is variously NO − 3 or ClO − 4 anion and n = 1 or 2. The coordination of the anions and ligands has been demonstrated by infrared and electronic spectral methods. Electron spin resonance spectral data show the square-pyramidal five-coordinated arrangement around copper(II) in these complexes. Parameters such as g ‖, g ⊥, A ‖, A ⊥, 〈 g〉 and 〈 A〉 calculated from electron spin resonance data in solid and solution state at room temperature as well as frozen solution indicate the presence of the unpaired electron in the d x 2 − y 2 or d z 2 orbital. These results are in good agreement with electronic and photoacoustic spectral studies.

Electron spin resonance and optical resonance studies on copper(II) complexes with vanadate, molybdate and tungstate anions

A series of complexes of the form Cu(An) n L x · yH 2O, where An = vanadate, molybdate or tungstate anion, L = pyridine, α-, β- or γ-picoline, n = 1 or 2; x = 1−4 and y = 0−3, have been synthesized and characterized by electron spin resonance, photoacoustic and electronic spectral studies as well as infrared spectroscopy in the solid and solution state. The different coordination sites of the ligands and anions have been interpreted from infrared and electronic spectral data. Electron spin resonance spectral data show the square planar or distorted octahedral (in a few cases five-coordinate geometry) stereochemistry around copper(II) in these complexes. Parameters such as g ∥, g ⊥, A ∥, A ⊥, 〈 g〉, 〈 A〉, α 2 and β 2 1 calculated from electron spin resonance data indicate the presence of unpaired electrons in d x 2− y 2 or d z 2 orbitals. The results of electronic and photoacoustic spectral studies are in good accord with ESR data.

Electron spin resonance and photoacoustic spectral studies on manganese(II) and copper(II) sulphate and thiocyanate complexes with hexamethylenetetramine

Electron spin resonance and photoacoustic spectral studies on manganese(II) and copper(II) sulphate and thiocyanate complexes with hexamethylenetetramine

Synthesis, electronic, photoacoustic and electron spin resonance investigations on some tetrathiocyanate binuclear mixed-metal complexes

Complexes of the type M 1M 2(SCN) 4 xL[M 1 = Ni(II); M 2 = Cd(II) and Hg(II) and L = pyridine, morpholine, dioxan, benzo(f)quinoline, 2,2′-bipyridine, 2,2′-bipyridine N, N′-dioxide, isonicotinic acid hydrazide and 1,10-phenanthroline: x = 2 or 4] have been synthesized and characterized by chemical analysis, magnetic susceptibility, infrared, electronic and photoacoustic (PAS) spectra as well as electron spin resonance (ESR) spectral studies in the solid and solution state. The different coordination sites have been investigated in these ligands towards metal coordination and the behaviour of thiocyanate anions studied. Electron spin resonance spectral data for copper complexes show the distorted octahedral stereochemistry around copper(II) in these complexes. The parameters such as g ∥, g ⊥, A ∥, A ⊥, < g>, < A> and α 2 calculated for the copper complexes from their ESR spectra indicate the presence of unpaired electron in d x 2- y 2 or d z 2 orbitals. The photoacoustic and electronic spectra of these complexes were studied in the solid state to see the nature of thiocyanate and overall symmetry of the complexes. The results on electronic and photoacoustic spectral studies are in good agreement with ESR data.