Search results for "Organic systems"
showing 4 items of 4 documents
Theoretical spectroscopy of organic systems
1999
Abstract The complete active space (CAS) SCF method in conjunction with the multiconfigurational second-order perturbation theory (CASPT2) has been applied to study the electronically excited states of basic organic compounds. As shown in the lecture with a number of examples, the CASPT2 method is capable of yielding accurate results for relative energies and other properties of excited states, provided that flexible one-electron basis sets are employed. The applications comprise an ample range of systems and problems, including polyenes, conjugated and unconjugated dienes, alternant and nonalternant hydrocarbons, polyenals, etc. As a whole these studies enable both qualitative and quantita…
Molecular Switching, Logics, and Memories
2013
The concepts of molecular switch, molecular logics and memories are intimately related. In this work a review of these three topics is given. While the main examples concern the field of inorganic chemistry, in a few cases organic systems are presented to better illustrate the concepts. The basic notions of the logics gates usually used by the nowadays computers is presented and the modus operandi to transpose these concepts to the molecular level is discussed. Examples of switches driven by external stimuli such as light-induced, metal-ion, redox, photobistable, and complexation–decomplexation are described in this chapter. The extension of switches working in solution to solid devices are…
Scintillation Measurements at Very High Solute Concentrations; Self Quenching-Structure Correlatios
1968
Abstract Measurements of the relative scintillation yields of some liquid organic systems were carried out with several highly soluble scintillator solutes. Self quenching was observed at high concentrations with some of the solutes, but not with others. The results were correlated with the ability of the solute molecules to come together, in a special configuration, close enough to form an association. A study of the atomic models of the solute molecules showed that those moleculeswith chromophor systems which were non-coplanar, or co-planar but shielded by substituent groups, did not produce self quenching. However, those solute molecules with unprotected co-planar chromophor systems did …
Population analysis of pair densities. A study on cyclic systems
2000
Abstract Pair population analysis seems a reliable method for evaluating atomic valency states and bond orders from the MO wavefunction of molecular systems. A test on some cyclic organic systems was performed. The results confirm the capability of the method to provide a correct description of the molecules in terms of simple VB approach.