Prototypical classical

In this section, the basic theory of molecular dynamics is presented. Starting from the BO approximation to the nuclear Schrddinger equation, the picture of nuclear dynamics is that of an evolving wavepacket. As this picture may be unusual to readers used to thinking about nuclei as classical particles, a few prototypical examples are shown. 

Compounds stmcturaHy related to the endogenous sympathomimetic amines epinephrine and norepinephrine have classically been employed as appetite suppressants. These agents, of which amphetamine [300-62-9], is the prototypical example, generally retain the phenethyl amine, but lack... 

A phenyl ethanol amine in which the nitrogen is alkylated by a long chain alphatic group departs in activity from the prototypes. This agent, suloctidil (43) is described as a peripheral vasodilator endowed with platelet antiaggregatory activity. As with the more classical compounds, preparation proceeds through bromination of the substituted propiophen-one ( ) and displacement of halogen with octyl amine. Reduction, in this case by means of sodium borohydride affords suloctidil (43). ... 

Benzodiazepines. Figure 1 (A) Chemical structure of classical [1,4] benzodiazepines. R1, R2, R2 R3, and R7 denote variable substitutents. (B) Chemical structure of the prototypical benzodiazepine diazeapm. 

Besides classical receptor classes that bind endogenous or naturally occurring ligands and act via prototypical intracellular signaling cascades, a considerable number of transmembrane proteins are referred to as receptors albeit their natural ligands are unknown or they do not... 

So-called second-order reactions— those involving the encounters of two ingredients-lie at the heart of chemistry. Indeed, the classic prototype of a chemical reaction takes the general form... 

This decade also saw the first major developments in molecular graphics. The first multiple-access computer was built at MIT (the so-called project MAC), which was a prototype for the development of modern computing. This device included a high-performance oscilloscope on which programs could draw vectors very rapidly and a closely coupled trackball with which the user could interact with the representation on the screen. Using this equipment, Levinthal and his team developed the first molecular graphics system, and his article in Scientific American [25] remains a classic in the field and laid the foundations for many of the features that characterize modern day molecular graphics systems. 

Linear triatomic anions The pioneering crystallographic studies of Odd Hassel140 on trihalides and related donor-acceptor species led to a far-reaching analysis of such Hassel compounds by Henry Bent.141 The triiodide ion (I3-, stable in aqueous solution) and other known linear trihalide XYZ- species also served as the prototype for Pimentel s incisive three-center MO analysis of hypervalency. We shall therefore begin with NBO/NRT investigation of a series of hypervalent and non-hypervalent triatomic anions in order to make contact with these classic studies. While ab initio studies add many quantitative details to the understanding of these species, the basic picture sketched by Bent and Pimentel is found to be essentially preserved. 

The natural prototype for the phenylalkylamines is mescaline (Structure 1), isolated from the peyote cactus (Lophophora williamsii) by Heffter in 1896 (100) and subsequently obtained synthetically by Spath in 1919 (218). Used for many centuries in the form of peyote by Indians in Mexico and the American Southwest (3), it is often referred to as one of the classic hallucinogens, along with psilocybin, psilocin, and LSD. Little structure-activity work was directed toward mescaline or its congeners until 1955, when Peretz et al. (174) reported that a-methyl mescaline (TMA) (8), which represented a hybrid of the structure... 

In terms of binding energy, classical hydrogen bonding may be enhanced by the increased acidity of the phenolic O—H, if the acceptor alcohol is non-phenolic [149, 182]. On the other hand, n interactions compete with classical hydrogen bonds [19, 54] and may even dominate the interaction, such as in the dimer of 1-naphthol [55]. This is not yet the case for phenol dimer, the prototype compound in this class [246, 247]. 

The conventional (or classical) neuroleptics comprise two classes of compounds with distinctive chemical structures 1. the phenothiazines derived from the antihistamine promethazine (prototype chlorpromazine), including Ltillmann, Color Atlas of Pharmacology 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 

---