Influence of structure

Table 14.1 Influence of structure variables on the properties of polyfvinyl formal)...

These general results have entailed much detailed chemical and pharmacological work on the influence of structural changes on particular items in the pharmacological action of morphine, e.g., its effect on respiration. ... 

Influence of Structure on Surface Films—Pitting Corrosion... 

In studies aimed at understanding the influence of structure on the reactivity of diazonium ions, Diener and Zollinger (1986) found that the NMR chemical shifts of the aromatic or heteroaromatic parent compounds provided a novel probe. This method can be applied both to substituted benzenediazonium ions and to various heteroaromatic diazonium ions, and it also provides semiquantitative information on the relative reactivities of the l,3,4-triazole-2-diazonium ion (12.5) and its deprotonated zwitterion (12.6). 

The description of reactive intermediates, which are short-lived species, is the main field of application of quantum chemical model calculations, due to the fact that the intermediates are difficult to observe and characterize. For example, the influence of structure on the stability of various carbenium ions — which have been used as models of the cationic chain end — and the delocalization of the positive charge were treated on this basis. 

Influence of Structure on the Cationic Polymerization of Substituted Styrenes... 

Substituted styrenes are often used for investigating influences of structure, solvent and initiators on the cationic polymerization 1,2). Under constant outer conditions,... 

Garcia-Viguera, C. and Bridle, R, Influence of structure on colour stability of anthocyanins and flavylium salts with ascorbic acid, Food Chem., 64, 21, 1999. 

M. Baviere and T. Rouaud. Solubilization of hydrocarbons in micellar solutions Influence of structure and molecular weight (solubilisation des hydrocarbures dans les solutions micellaires influence de la structure et de la masse moleculaire). Rev Inst Franc Petrol, 45(5) 605-620, September-October 1990. 

Hosier H, Iwasita T, Baumgartner H, Vielstich W. 2001b. Pt-Ru model catalysts for anodic methanol oxdiation Influence of structure and composition on the reactivity. Phys Chem Chem Phys 3 337. 

There have been many papers reporting studies on the influence of structure and conditions of the medium. Specifically, the kinetic behavior of enzymatic reactions in two-phase media was probed [7,25,27,63]. The reaction localization and the interaction between mass transfer and metabolism in compartmentalized media are interesting phenomena. Their study in the laboratory are useful for optimizing the operating conditions of bioreactors in a preparative scale. In addition, they also help to understand better the behavior of enzymatic systems in vivo. 

Horwatt, S. W., Feke, D. L., and Manas-Zloczower, I., The influence of structural heterogeneities on the cohesivity and breakup of agglomerates in simple shear flow. Powder Technol. 72, 113-119 (1992a). 

S. Yesslers, R. Boistelle, A. Delacourte, J. C. Guyot, and A. M. Guyot-Hermann, Influence of structure and size of crystalline aggregates on their compression ability, Drug Dev. Ind. Pharm., 18, 539 (1992). 

The influence of structured electrodes or multipoint electrodes, which enhance the local electric field [20,21], as well as the effect of discharge polarity [20-22] and gap length [21,23,24], was investigated. 

Zhang Y, Kua J, McCammon JA (2003) Influence of structural fluctuation on enzyme reaction energy barriers in combined quantum mechanical/molecular mechanical studies. J Phys Chem B 107 ... 

Damas, C., Vannier, L., Naejus, R. and Coudert, R. (1999) Influence of structural modifications near the polar head of sodium carboxylates on their aqueous solution behaviour. Colloids and Surfaces A Physicochemical and Engineering Aspects, 152, 183-187. 

To evaluate the influence of structural parameters governed by the cyclophosphazene core concerning the valency and the spatial orientation of epitopes, as well as the nature of linkers directly related to the ligation technique used for the mannoside incorporation, the authors performed preliminary kinetic turbidimetric assays with Con A. Insoluble cross-linked complexes formed rapidly for all compounds, without marked difference for the hexavalent analogues. On the other hand, the incorporation of additional mannosyl units led merely to statistical binding-affinity enhancements, notably for the less-dense decamer 194, which presents favorable extended intersugar distances. 

When he interviewed with Meyer in 1926, Mark outlined a typically thorough program. He proposed a team of organic and physical chemists, and physicists who would evaluate the influence of structure on properties such as rigidity, elasticity, melting point, and water absorption. Work, he proposed, would shift toward new material development and into the manufacturing facilities to evaluate the effects of processing... 

Several papers have been devoted to the subject of reactions of phosphoranes with carboxylic acids and their derivatives. Thus triphenylphosphine dibromide (111) in acetonitrile cleaves lactones,93 while the corresponding dichloride (112) converts esters into acid chlorides.94 The reactions of esters with phosphorus pentachloride (101) have been studied further,95 and the influence of structural changes on the yields of products (113) and (114) has resulted in minor modifications to the mechanism previously96 outlined. 

Even now it is still impossible to present a comprehensive and consistent treatment of the influences of structure on chemical shifts of sp3 hybridized carbon atoms. In turn, this has led to some frustration concerning the applicability of 13C NMR in confirmation and elucidation of the structures of aliphatic molecules (especially if they are highly substituted) and its ability to monitor electronic states, on which so many hopes had been pinned. Nevertheless, the number of publications using 8C values empirically is still increasing. Thus, it seems that a situation has been reached where physical understanding is becoming buried under an overwhelming mass of uninterpreted or even misinterpreted data. 

As already stated, theoretical calculations are as yet too involved and not accurate enough for routine 13C NMR spectral interpretation, particularly where more complicated molecules are concerned probably this situation will not change in the near future. Therefore, different approaches have been developed to identify certain influences of structural modifications, for example substituent introduction, on 13C shieldings. The partition of oA into two local (o A and o A) and several nonlocal contributions (30,32) is reasonable on physical grounds. On that basis, the factors that play a role in organic molecules were divided into two classes (56) ... 

M. Rahmandoust, A. Ochsner, Influence of structural imperfections and doping on the mechanical properties of single-walled carbon nanotubes., Journal of Nano Research, vol. 

Influence of Structure and Chain Length of Surfactant on the Nature and Structure of Microemulsions... 

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