Interplay between experiment and theory

The interplay between experiment and theory computational NMR spectroscopy of carbocations... 

Continued interplay between experiment and theory has prompted the development of a new method to measure the energy- and angle-resolved... 

Fruitful interplay between experiment and theory has led to an increasingly detailed understanding of equilibrium and dynamic solvation properties in bulk solution. However, applying these ideas to solvent-solute and surface-solute interactions at interfaces is not straightforward due to the inherent anisotropic, short-range forces found in these environments. Our research will examine how different solvents and substrates conspire to alter solution-phase surface chemistry from the bulk solution limit. In particular, we intend to determine systematically and quantitatively the origins of interfacial polarity at solid-liquid interfaces as well as identify how surface-induced polar ordering... 

The measured electronic structure, occupied or unoccupied, provides the fullest information when also combined with theory. Electronic structure calculations in surface chemistry have advanced immensely in the past decades and have now reached a level of accuracy and predictive power so as to provide a very strong complement to experiment. Indeed, the type of theoretical modeling that will be employed and presented here can be likened to computer experiments, where it can be assumed that spectra can be computed reliably and thus computed spectra for different models of the surface adsorption used to determine which structural model is the most likely. In the present chapter, we will thus consistently use the interplay between experiment and theory in our analysis of the interaction between adsorbate and substrate. Before discussing what quantities are of interest to compute in the analysis of the surface chemical bond, we will briefly discuss and justify our choice of Density Functional Theory (DFT) as approach to spectrum and chemisorption calculations. 

Tetrahedral intermediates, derived from carboxylic acids, spectroscopic detection and the investigation of their properties, 21, 37 The interplay between experiment and theory computational NMR spectroscopy of carbocations, 42, 125... 

The fundamental aspects related to the thermochemistry, structure and reactivity of gas-phase ions are usually considered the domain of gas-phase ion chemistry. By extension, some of these same properties are often obtained for simple neutrals and radicals from methods used in gas-phase ion chemistry. A wide range of experimental techniques can be used for this purpose, and instrumental developments have contributed a great deal to our knowledge of gas-phase ions. Theoretical calculations have also played an important role and gas-phase ion chemistry has witnessed a very lively interplay between experiment and theory in recent years. 

The determination of the timescales and of the several chaimels of deactivation of the excited molecule is essential. For this reason, a strong interplay between experiments and theory is mandatory. The first role of the theoretical study is to elucidate the electronic structure of the molecules, to determine the low-lying electronic transitions, and to assign... 

Theoretical calculations on model PCET systems have assisted in the interpretation of experimental data and have provided insight into the underlying fundamental principles of PCET reactions. The theoretical framework described in this chapter enables the prediction of experimentally testable trends in rates and kinetic isotope effects. The interplay between experiment and theory will be vital to further progress in the field. 

Organophosphorus Chemistry series regularly lists new mass spectra in the Physical Methods chapter . With this in mind, an approach which considers fundamental aspects of organophosphorus ions (i.e. structure and reactivity) in the gas phase has been adopted. The gas-phase structure and reactivity of ions can be probed via several different techniques, including thermochemical measurements, kinetic energy release of metastable ions, collisional activation mass spectrometry, neutralization reionization mass spectrometry and ion-molecule reactions. An example is the molecule HCP (Table 1) its ionization potentiaP, proton affinity and the IR and rotational spectroscopy of the HCP ion " have all been determined in the gas phase. Another important tool for understanding the structure and reactivity of gas phase ions is ab initio molecular orbital theory. With advances in computational hardware and software, it is now possible to carry out high-level ab initio calculations on smaller systems. Indeed, the interplay between experiment and theory has fuelled many studies ... 

Taking into account that methylenecyclopropene is a highly reactive compound, the experimentally determined gas-phase spectrum might not be easily accessible for some time. The interplay between experiment and theory therefore has importance for gaining further insight into the properties of this fundamental nonalternant hydrocarbon. 

Examples of several current classical mechanical approaches to determining the solution conformation of oligosaccharides are presented in the following sections. The synergistic interplay between experiment and theory is nowhere more essential than in the elucidation of oligosaccharide conformations, and some aspects of experimental methods and their limitations are referred to as necessary. 

Coppens, R, and Volkov, A. (2004). The interplay between experiment and theory in charge-density analysis, Acto Cryst. A 60, 5, pp. 357-364. 

We highlight some recent work from our laboratory on reactions of atoms and radicals with simple molecules by the crossed molecular beam scattering method with mass-spectrometric detection. Emphasis is on three-atom (Cl + H2) and four-atom (OH + H2 and OH + CO) systems for which the interplay between experiment and theory is the strongest and the most detailed. Reactive differential cross sections are presented and compared with the results of quasiclassical and quantum mechanical scattering calculations on ab initio potential energy surfaces in an effort to assess the status of theory versus experiment. 

A. Sharma, A.G. Namdeo and K.R. Mahadik, Molecular Markers New Prospects in Plant Genome Analysis , Pharmacognosy Rev., 2008, 2, 23, [online computer file]. Avail. URL http //www.phcog.net/reviews/issue3/4.pdf H.-U. Siehl, The Interplay between Experiment and Theory Computational NMR Spectroscopy of Carbocations , Adv. Phys. Org. Chem., 2008, 42, 125. 

Research on blue phases has always been characterized by a close interplay between experiment and theory. The initial experiments were reported around 1979 in 1980, Homreieh and Shtrikman published the first Landau... 

Gloaguen E, de Courcy B, Piquemal JP, Pilme J, Parisel O, Pollet R, Biswal HS, Piuzzi F, Tardivel B, Broquier M, Mons M (2010) Gas-phase folding of a two-residue model peptide chain on the importance of an interplay between experiment and theory. J Am Chem Soc 132 11860... 

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