The vibrational spectrum of the pyridinium ion, C5H5NH+, and the N-deuterated species has been studied in several pyridinium salts. By comparison with benzene and deuterobenzene (with which the pyr...

Vibrational spectra of pyridinium salts

Analytic gradient techniques have been used to predict the harmonic vibrational frequencies of HCN, H2CO, H2O, CH4 and NH4+ at several levels of molecular electronic structure theory. Basis sets of double zeta, double zeta plus polarization, and extended plus polarization quality have been used in conjunction with self‐consistent‐field and configuration interaction methods. For the four spectroscopically characterized molecules, comparison with theory is particularly appropriate because experimental harmonic frequencies are available. For the 16 vibrational frequencies thus considered, the DZ SCF level of theory yields average errors of 166 cm−1 or 8.0%. The DZ+P SCF results are of comparable accuracy, differing on the average from experiment by 176 cm−1 or 8.3%. With the extended basis set, the comparable SCF frequency errors are only slightly less. The explicit incorporation of correlation effects qualitatively improves the agreement between theoretical and experimental harmonic vibrational frequencies....

A systematic theoretical study of harmonic vibrational frequencies: The ammonium ion NH4+ and other simple molecules

Characterization of 12-tungstophosphoric acid and related salts using photoacoustic spectroscopy in the infrared region: I. Thermal stability and interactions with ammonia

Both the structure of Pt-intercalated K4Nb6O7 catalyst and the photocatalytic activity on the water splitting in aqueous carbonate salt solution were studied using various kinds of analytical measurements such as FT-IR, EXAFS, TEM, SEM and TPR. K4Nb6O17 was the layered semiconductor which have two kinds of interlayer spaces (interlayers I and II), and it was found by FT-IR that the [ Pt(NH3)4]2+ cation was preferentially intercalated only into the interlayer I of K4Nb6O17. Fine Pt metal particles less than 6 A (1 A = 0.l nm) were prepared homogeneously in the interlayer space I by the photoreduction method. By H2 reduction, some Pt particles grew more than 15 A and contributed to the destruction of the layered sheet. The photocatalytic water splitting reaction occurred by the addition of carbonate salt in spite of the exposure of Pt on the outer surface of catalyst. The photocatalytic activity of the Pt/K4Nb6O17 prepared by the photcreduction was higher than that prepared by the H2 reduction. The deactivation of the catalyst was not observed in the carbonate aqueous solution for long time. The reaction mechanism that the Pt panicles in the interlayer I acted as H2 evolution site and the O2 evolved in the interlayer II was proposed.

Photocatalytic activity and reaction mechanism of Pt-intercalated K4Nb6O17 catalyst on the water splitting in carbonate salt aqueous solution

Publisher Summary This chapter provides a critical review of the preparation, characterization (which is often incomplete), and properties of cyanide complexes of the transition metals. It focuses on structural, thermodynamic, and kinetic data. Two prominent features of transition metal cyanide chemistry are the wide range of metal:ligand ratios in complexes and the existence of many metals in low oxidation states. The chapter discusses the bearing of the physical state of metal cyanides on structural investigations. There are two important consequences of the fact that cyanide is an ion and not a neutral molecule: metal cyanides and their complexes are nonvolatile salts rather than volatile molecular entities and much of their chemistry is concerned with processes and measurements in solution in solvents of high complexing power, so that differences in complexing by solvent and ligand are involved. The chapter considers the effect of cyanide on the stabilities with respect to oxidation and reduction of metal ions in aqueous media, taking Fe(II) and Fe(III) as an example.

J.P. Mathieu

Papers

Spectres de vibration et fréquences fondamentales de composés de co-ordination hexamminés

Spectres de vibration et fréquences fondamentales de composés amminés du platine

Les frequences fondamentales de vibration de l'ion NH4+

Spectres et structure de composés de coordination pyridines

Spectres de vibration des cristaux piezoelectriques—VII: Cuprocyanure de potassium [1]