Acidity structural effects

The greater positive character hence the increased acidity of the O—H proton of 2 2 2 tnfluoroethanol can be seen m the electrostatic potential maps displayed m Figure 1 8 Structural effects such as this that are transmitted through bonds are called indue tive effects A substituent induces a polarization m the bonds between it and some remote site A similar inductive effect is evident when comparing acetic acid and its trifluoro derivative Trifluoroacetic acid is more than 4 units stronger than acetic acid... 

The effect of structure on acidity was introduced m Section 1 15 where we developed the generalization that electronegative substituents near an lomzable hydrogen increase Its acidity Substituent effects on the acidity of carboxylic acids have been extensively studied... 

Removal of the the related ethoxymethyl group from an imidazole with 6 N HCl at reflux is slow and low yielding. Small structural effects at a site seemingly remote from the MOM group can have a significant influence on the deprotection process. The MOM group in compound a is easily removed with acid, but the cleavage with HCl in compound b proved quite difficult. ... 

Substituent effect, additivity of, 570 electrophilic aromatic substitution and, 560-563 summary of. 569 Substitution reaction, 138 Substrate (enzyme), 1041 Succinic acid, structure of, 753 Sucralose, structure of. 1006 sweetness of, 1005 Sucrose, molecular model of. 999 specific rotation of, 296 structure of, 999 sweetness of, 1005 Sugar, complex, 974 d, 980 L, 980... 

Earlandite structure, 6,849 Edge-coalesced icosahedra eleven-coordinate compounds, 1, 99 repulsion energy coefficients, 1,33,34 Edta — see Acetic acid, ethylenediaminetetra-Effective atomic number concept, 1,16 Effective bond length ratios non-bonding electron pairs, 1,37 Effective d-orbital set, 1,222 Egta — see Acetic acid,... 

Sodium a-sulfonated fatty acid esters of long-chain alcohols have a structural effect on the Krafft point different from that of amphiphiles with short alkyl chains [60]. In a series of homologs with the same total carbon number the Krafft points are highest when the hydrophilic alkyl chain lengths in the a-sulfonated fatty acid and the alcohol are fairly long and equal. In this case the packing of the molecules becomes close and tight. 

The effect of various types of inhibitors with respect to structure and solubility on the formation of N-Nitrosodiethanolamine was studied in a prototype oil in water anionic emulsion, Nitrosation resulted from the action of nitrite on diethanolamine at pH 5.2-5.A, Among the water soluble inhibitors incorporated into the aqueous phase, sodium bisulfite and ascorbic acid were effective. Potassium sorbate was much less so. The oil soluble inhibitors were incorporated into the oil phase of the emulsion. 

Hoshi N, Kida K, Nakamura M, Nakada M, Osada K. 2006. Structural effects of electrochemical oxidation of formic acid on single crystal electrodes of palladium. J Phys Chem B 110 12480-12484. 

Adzic RR, Tripkovic AV, Markovic NM. 1983. Structural effects in electrocatalysis oxidation of formic acid and oxygen reduction on single-crystal electrodes and the effects of foreign metal adatoms. J Electroanal Chem 150 79-88. 

Markovic NM, Adzic RR, Cahan BD, Yeager EB. 1994. Structural effects in electrocatalysis— Oxygen reduction on platinum low-index single-crystal surfaces in perchloric-acid solutions. J Electroanal Chem 377 249-259. 

In analogy to the reaction of CDI with carboxylic acids, the even more reactive NJf -carbonyldi-1,2,4-triazole 5bl has been used instead of CDI in cases where specific structural effects require a higher reactivity of the azolide. On the other hand, the example of the last paragraph of the preceding section showed that A -carbonyldi-benzimidazole 151 141 and AyV -carbonyldibenzotriazole 151 have been useful for the syntheses of azolides with reduced reactivities when these are essential and sufficient for the specific reaction in question. 

Violante A, Krishnamurti GSR, Pigna M (2008) Mobility of trace elements in soil environments. In Violante A, Huang PM and Gadd G (eds) Wiley-JUPAC series on biophysico-chemical processes of metals and metalloids in soil environments. John Wiley Sons, Hoboken, USA Waltham AC, Eick MJ (2002) Kinetic of arsenic adsorption on goethite in the presence of sorbed silicic acid. Soil Sci Soc Am J 66 818-825 Waychunas GA, Fuller CC, Rea BA, Davis J (1996) Wide angle X-ray scattering (WAXS) study of two-line ferrihydrite structure Effect of arsenate sorption and counterion variation and comparison with EXAFS results. Geochim Cos-mochim Acta 60 1765-1781... 

In Section 3.4, structural effects were often discussed in conjunction with the nature of the solvent. As emphasized in the introduction to this book, the fluorescence emitted by most molecules is indeed extremely sensitive to their microenvironment (see Figure 1.3), which explains the extensive use of fluorescent probes. The effects of solvent polarity, viscosity and acidity deserves much attention because these effects are the basis of fluorescence probing of these microenvironmental characteristics and so, later chapters of this book are devoted to these aspects. The effects of polarity and viscosity on fluorescence characteristics in fluid media and the relevant applications are presented in Chapters 7 and 8, respectively. The effect of acidity is discussed in Sections 4.5 and 10.2. This section is thus mainly devoted to rigid matrices or very viscous media, and gases. 

TABLE IV. Effect of Acid Structure in Methanol to Polyethylene.a Grafting of Styrene in ... 

G. M. Wall, J. M. Baker, Metabolism of 3-(/>-Chlorophenyl)pyrrolidine. Structural Effects in a Prototype y-Aminobutyric Acid Prodrug to Lactam and y-Aminobutyric Acid Type Metabolites , J. Med. Chem. 1989, 32, 1340-1348. 

---