Substitution, influence

Electrophilic aromatic substitution, influence of sulphinyl and sulphonyl groups on 532, 533... 

Sakai H, Tsai AG, Rohlfs RJ, et al. Microvascular responses to hemodilution with Hb vesicles as red blood cell substitutes influence of O2 affinity. Am J Physiol 1999 276 H553. 

Recently, Ribeiro da Silva et al. have described another QSAR study. The authors studied the substitution influence on the N - O bond dissociation enthalpies of a series of QDO and its relationship to antitumor activity [163]. 

In addition, the effect of para-substitution of the aryl group in triphenyl phosphine was studied. Substitution influences the IR frequencies of the complexes RhH(P(C6H4R)3)2(CO)2, as shown in Table 6.6. Both hydride-metal and C-O stretching frequencies show a regular increase with %-value. The lower electron density on the metal leads to a decrease in back-donation from rhodium to the carbonyl ligand and hence higher frequencies for the CO stretches are... 

This series also shows, as was discussed for substituted 2-alkoxy-2-oxo-l,3,2-dioxaphos-phorinanes that substitution influences kj to the larger extent than kp. Apparently, in all these systems the entropy of activation decreases with substitution more rapidly for termination than for the propagation reaction. 

Many substituted azobenzenes belong to the azobenzene type, as well. Substitution may shift the n —> it band from 440 nm (azobenzene), to 465 nm (hexamethylazobenzene), to 480 nm (2,2 -dimethyl-4,6,4 ,6 -tetra-tert.butylazobenzene), and even to 520 nm (hexaphenylazobenzene). Hydrocarbon, halogen, nitro, carboxy, acetyl, hydroxy, m-amino" and even 2,2 4,4 ,6,6 hexaphenyl substitution— influences the (7i,7t )-(n,7i ) state energy gap, but not so much as to shift the molecule into the aminoazobenzene group. In the context of this book, it is important that the long-chain and polymeric molecules containing azobenzene units coupled by means of hydroxy and carboxy substituents are of the azobenzene type. 

Apatite Crystal Substitutions Influence Bone Strength and Solubility... 

Alkyl-substitution influences the absorption spectra in thin films mainly by their influence on the co-planarity of the molecules, particularly in the excited state, and only to a minor extent by their electron pushing (inductive) effect (see [181]). The latter should result in a red shift which is not observed in absorption spectra of thin films but can be detected in the fluorescence spectra. In absorption spectra, major blue shifts of the absorption peaks occur if larger differences in the torsion angle between different rings are induced by the substituents. As long as the co-planarity is not distorted, quite similar absorption spectra are observed if compared to unsubstituted oligothiophenes [13,182]. 

Fig. 4.30) with various substitution pattern at Cl and C2 were investigated. Experiments with alkyl substituents at C2, in place of the sulfur heteroatoms, eliminate the viability of a chelation-controlled selectivity and reveal the significance of geminal substitution [geminal substitution influenced the selectivity in other oxocarbenium ion systems [108]]. Perturbation of the Cl substituent of the oxocarbenium ion intermediate has little effect on reaction stereoselectivity, and analysis of this observation lends additional support for stereoelectronically preferred inside attack of the nucleophile. The results demonstrate that selective formation of the 1,4-c/s product 84 does not require a chelated transition stracture, reinforcing the utility of the inside attack model to analyze the reactivity of complex five-membered ring oxocarbenium ion intermediates. 

Products of Mechanical Recycling Substituting Influence Parameters Ecological Break-even Point Mechanical vs. Feedstock/Energy Recovery... 

The President of the United States is to have power to return a bill, which shall have passed the two branches of the Legislature, for reconsideration but the bill so returned is to become a law, if upon that re-consideration it be approved by two thirds of both houses. The King of Great Britain, on his part, has an absolute negative [veto] upon the acts of the two houses of Parliament. The disuse of that power for a considerable time past, does not affect the reality of its existence and is to be ascribed wholly to the crown s having found the means of substituting influence to authority, or the art of gaining a majority in one... 

This method requires that a very small amount of JS chains provide information on the phase separation in PVME-PS-PS mixtures. We established that the observed changes in fluorescence intensity do not arise from the phase separation of PVME-PJ. Indeed, the observed phase separation temperature in some PVME-JS-PS mixtures does not depend on the molecular weight of the label PS in the range 30,000-300,000 (14). In addition, agreement was found between tjjie SANS data on PVME/PS dg and the fluorescence data on PVME/PS-d /PS (Fig. 4). That is, PS samples the PVME-PS mixture and is valid for the study of molecular weight as well as isotopic substitution influences on the phase diagrams. ... 

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