摘要:

A wide range of inorganic substrates undergo autocatalytic oxidation by moderately concentrated (1–4 M) nitric acid. In addition to behaving as clock reactions in closed (batch) systems, several of these oxidations exhibit bistability in open continuous-flow stirred tank reactor (CSTR) systems and wave propagation in unstirred configurations. Analysis of experimental studies, combined with detailed numerical simulation, suggests several mechanistic features which are common to nitric acid oxidations. The mechanistic scheme also affords insight into why nitric acid oxidations, in contrast to many other autocatalytic reactions, have defied efforts to convert them into chemical oscillators.

ISSN:0260-3594    

DOI:10.1080/02603598608072276

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

In the last 10 years, ligand-field splittings on core levels of main group compounds (e.g. compounds of Zn, Cd, In, Tl, Xe, I) in the gas phase have been observed using high resolution photoelectron spectroscopy. These splittings on d9and p5ion states are analogous to the well-known splittings of valence d levels in transition metals, and are characterized using the usual crystal-field and spin-orbit Hamiltonian. The noncubic C02term dominates these splittings. The C02values are sensitive to structure and bonding. For example, C02increase for R2Zn compounds in the order R=CI < Br < I < Me < Et-just the order of increasing γ donor strength, and the In 4d splitting has been useful in showing that indium trihalides are dimers in the gas phase. Simple calculations are useful for calculating these splittings, especially point charge calculations for the I splittings in alkali iodides. The C02Hamiltonian term transforms like the nuclear quadrupole Hamiltonian, making it possible to observe the transmission of the ligand field through the atom to the nucleus. Monochromatized synchrotron radiation as a photoelectron source will be important for observing these splittings in more gas phase compounds of a variety of elements, and also for examining core level broadenings on surfaces.

ISSN:0260-3594    

DOI:10.1080/02603598608072277

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0260-3594    

DOI:10.1080/02603598608072275

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor