Resonance characteristic feature

An SFG signal exhibits characteristic features at frequencies of molecular vibrational resonances similar to the vibrational fingerprints of conventional IR... 

Hydrocarbons may be differentiated by their solubility in sulphuric acid since unsaturated hydrocarbons are soluble in concentrated sulphuric acid as are those arenes which are readily sulphonated, whereas the saturated alkanes and lesser reactive arenes are insoluble in this reagent. The presence of an alkene, alkyne or arene is usually readily apparent from an inspection of the infrared and nuclear magnetic resonance spectra, the characteristic features of which are fully discussed in Sections 5.2., 5.3 and 6.1 respectively and in Chapter 3. 

The critical temperature Tc and the isotope coefficient a at the shape resonance are shown in Fig. 7. The result shows the characteristic feature of the Tc amplification by a shape resonance at the maximum critical temperature Tc max the isotope coefficient is close to zero or negative, and... 

In the reduction of acetylene with molybdothiol and molybdoselenol complex catalysts, the effects of structural variation in ligands, variety of coordination-donor atom, kind of transition-metal ion, and other factors have been surveyed systematically. These factors have profound effects on the catalytic activity. The Mo complexes of cysteamine (or selenocysteamine), its N,N-dimethyl derivative, and its /3-dimethyl derivative give ethylene, ethane, and 1,3-butadiene, respectively, as the major product. The Co (I I) complexes of cysteine and cysteamine show higher catalytic activity than do the corresponding Mo complexes, and the order of the activity in the donor atom, namely S >Se 0 in the Co(II) complexes is consistent with that in the Mo complex systems. On the basis of electron spin resonance (ESR) features of these Mo complex catalysts, a relationship between their ESR characteristics and catalytic activities is discussed. 

Examples of 1,3-dipoles include diazoalkanes, nitrones, carbonyl ylides and fulminic acid. Organic chemists typically describe 1,3-dipolar cycloaddition reactions [15] in terms of four out-of-plane 71 electrons from the dipole and two from the dipolarophile. Consequently, most of the interest in the electronic structure of 1,3-dipoles has been concentrated on the distribution of the four Jt electrons over the three heavy atom centres. Of course, a characteristic feature of this class of molecules is that it presents awkward problems for classical valence theories a conventional fashion of representing such systems invokes resonance between a number of zwitterionic and diradical structures [16-19]. Much has been written on the amount of diradical character, with widely differing estimates of the relative weights of the different bonding schemes. 

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