Straightforward Example

Atom 0 is deposited at an arbitrary location, e.g., at the origin of a coordinate system, (0,0). 

The neighbors of atom 0 are put in place. The angle at which atom 1 is aligned is arbitrarily taken as 0°. The bond length used was provided along 

The preceding example was relatively simple and straightforward to accomplish because it lacked several common difficulties, including the following. 

What is the angular demand of these ring systems  

Ring junction collision Persubstitution overcrowding Hexagonal wraparound 

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Bromoquinolines behave in the Suzuki reaction similarly to simple carbocyclic aryl bromides and the reaction is straightforward. Examples include 3-(3-pyridyl)quinoline (72) from 3-bromoquinoline (70) and 3-pyridylboronic acid (71) (91JOC6787) and 3-phenyl-quinoline 75 from substituted 3,7-dibromoquinoline 73 and (2-pivaloylaminophenyl)boronic acid 74 (95SC4011). Notice that the combination of potassium carbonate and ethanol resulted in debromination at the C(7) position (but the... 

The utility of base catalyzed condensations of esters to give jS-ketoesters is well known. A straightforward example of this reaction is the intermolecular cyclization of diethyl succinate giving 2,5-dicarbethoxy-l,4-cyclohexanedione, which can in turn be easily decarboxylated to give 1,4-cyclohexanedione. 

Antagonists can produce varying combinations of dextral displacement and depression of maxima of agonist dose-response curves. The concentration-related effect of an antagonist on the system response to a single concentration of agonist constitutes what will be referred to as an inhibition curve. One of the most straightforward examples... 

In practice, one proceeds as follows. The value of bh >s determined for the reaction with a series of acids of similar structure, that is, for carboxylic acids or ammonium ions, etc. Limiting the data to a single catalyst type improves the fit. since the inclusion of data for a second ype of acid catalyst might define a close but not identical line. This means that Ga may be somewhat different for each catalyst type. A plot of log(kBH/p) versus log(A BH(7//i) is then constructed. This procedure most often results in a straight line, within the usual —10-15 percent precision found for LFERs. One straightforward example is provided by the acid-catalyzed dehydration of acetaldehyde hydrate,... 

As the most straightforward example we take the titration of a strong acid (HCl) with a strong base (NaOH) in a dilute solution (initial concentration C) ... 

The numerous straightforward examples of internal displacement reactions leading to isolable cyclic products will not be discussed here, but only, for the most part, those ionization reactions in which a cyclic intermediate or transition state is deduced from the rearranged structure of the product. A well-known example is mustard gas and other alkyl chlorides with sulfur on the /3-carbon atom. Although mustard gas is a primary and saturated alkyl chloride, its behavior is like that of a typical tertiary alkyl chloride. It reacts so fast by a first order ionization that the rate of the usual second order displacement reaction of primary alkyl halides is not measureable. Only the ultimate product, not the rate, is determined by the added reagent.228 Since the effect of the sulfur is too large to be explicable in terms of a carbon sulfur dipole or similar explanation, a cyclic sulfonium ion has been proposed as an... 

Finally, we consider a straightforward example of three consecutive steps as in the scheme... 

Relative Risks of Nitrosamines. The mere existence of reproducible variations in carcinogenicity from one nitrosamine to another is directly relevant to the question of potential human health hazards from environmental nitrosamines. The problem of nitrosamines in cooked bacon is a simple and straightforward example. 

Many of the most versatile and widely used syntheses of pyrimidines are straightforward examples of [3+3] condensations of amidines, guanidines, ureas and thioureas with 1,3-dielectrophiles, and clearly a considerable measure of control over the degree and nature of the substitution pattern in the final product is possible by appropriate choice of the two three-component units. Representative examples are given in equations (112)—(115), and the use of sulfamide in place of amidines, etc., allows the method to be extended to the synthesis of polyheteroatom systems e.g. equation 116). 

Another less straightforward example is the synthesis of the conformationally mobile aza[14]annulene 40 in 50 % yield, which was accomplished by photolysis of endo-l 1 -azidotetra-cyclo[6.5.0.09 53.0lo,12]trideca-2,4,6-triene (39) at — 70 jC.138... 

Acid phosphatase gives a straightforward example of the accumulation of a phosphorylenzyme intermediate with rate-determining breakdown ... 

Hydrolysis is strong acid in which all hydroxo bridges are cleaved, followed by identification of the various mononuclear species and a determination of their molar ratios, may provide extremely valuable information. A straightforward example is the cleavage of the tetra-nuclear species Cr4(NH3)12(OH)66+, which yields Cr(H20)63+ and cis-Cr(NH3)4(H20)23+ in a ratio of 1 3 (40). Since it could be demonstrated at the same time that the polynuclear cation does not exhibit acid base properties in the pH region for terminally coordinated water, it was concluded that the only possible structure was 6 in Fig. 1, as later confirmed by a crystal-structure analysis (41). 

In contrast to a chemical property which can be measured, a molecular descriptor is computed from the molecular structure. Contained in the structural information are the atoms making up the molecule and their spatial arrangement. From the coordinates of the atoms, the geometric attributes (i.e., the size and shape of the molecule) can be deduced. A straightforward example is the molecular mass, which is computed by adding up the masses of the individual atoms making up the molecule and indicated in the elemental composition. The result is accurate since the atomic masses are independent of the chemical bonds with which they are involved. However, the molecular mass reflects few of the geometrical and chemical attributes of a compound and M is therefore a poor predictor for most properties. 

The most commonly used method is the direct measurement of a decay rate by pulsed excitation and time resolved detection. The most straightforward example of this technique is laser induced fluorescence applied to alkali Rydberg atoms. Alkali atoms are typically contained in a glass cell, which also holds a known pressure of perturber gas. The alkali atoms are excited to the Rydberg state at time t = 0 and the time resolved fluorescence from the Rydberg atoms is detected... 

Thus we have a straightforward example of the application of scientific procedure of the sort originally used to prove the existence of psi phenomena. We went from a stage of anecdote and crude experimentation to sophisticated experimentation that gave us precise information in which we could put great confidence. Now let us look at some of the human complexities that frequently enter into the scientific process in general and into parapsychological research. 

The frequent predictability of transient insomnia provides opportunity for prevention. Perhaps the most straightforward example would involve transient... 

Only a relatively few kinetic schemes for complex reactions have differential rate expressions which can be integrated straightforwardly. Examples are the following. 

This is a straightforward example of moving from mechanism to rate expression. 

First-Order Kinetics, K[A] Unimolecular processes, such as ligand dissociation from a metal center or a simple homolytic or heterolytic cleavage of a single bond, provide a straightforward example of a first-order reaction. The kinetics of this simple scheme, Equation 8.5, is described by a first-order rate law, Equation 8.6, where A stands for reactants, P for products, [A]0 for initial concentration of A, and t for time. The integrated form is shown in Equation 8.7 and a linearized version in Equation 8.8. 

A particularly useful kind of biomarker used with increasing frequency during recent years consists of adducts of xenobiotics or their metabolites to biomolecules. A particularly straightforward example of such an adduct measured for many years as evidence of exposure is carboxyhe-moglobin, COHb, produced when inhaled carbon monoxide adds to blood hemoglobin, Hb ... 

Although the additions to 1,3-dienes in equations (167) (Hammond and Warkentin, 1961) and (168) (Young et al., 1956) illustrate the syn preference, their mechanisms are more complex than is indicated here. The 1,4-elimination in (169) (Cristol et al., 1955) does appear to be a straightforward example of syn preference. 

A straightforward example of this type of reaction is provided by the addition of hydride nucleophile (H -) to aldehydes and ketones. Recall from Section 10.7 that the organic chemist s sources of hydride nucleophile are lithium aluminum hydride and sodium borohydride. The reaction follows the basic conditions mechanism as illustrated by the following general equation using A1H4 as the nucleophile ... 

A straightforward example of the type of information we can obtain from the vibrational spectra may be obtained from the behavior of the N-H stretching frequencies. In Table V the 10 N-H stretching frequencies in the aR helical conformation and the C7eq conformation are given as well as the residue in which they occur. We note first of all that the vibrational frequency of the N-H is extremely sensitive to the location of the residue in the chain. 

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