Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Aliphatic bases

Aininonhni oi amine salts, if present, emit the smell of ammonia or amine if the salt of an insoluble oiganic base is present amine, alkalniif), it may be precipitated as a liquid or solid Salts of aliphatic bases and bases such as benzylanvne... [Pg.330]

Roder and Bayer (44) reported the further study of a series of thiol/ Fe(III) heme/base complexes, varying both the thiol and the base, the latter being either a pyridine or an aliphatic base. They showed that there was a correlation between the acid dissociation constants >K(RSH) or )K(base) and the gr and g3 values, Fig. 3. This could well imply that,... [Pg.131]

The Group Containing Aliphatic Bases with an Aromatic Nucleus... [Pg.144]

Other aliphatic bases (amines and thiols) are oxidized by similar pathways their electrochemistry is discussed to a limited extent in Chapter 11. [Pg.458]

The less favorable entropies of the polyamine ligand reactions are attributed to the greater loss of rotational freedom about the C N bonds of the aliphatic bases upon metal-ion coordination. It was observed that the coordinated polyamine of a cobalt dioxygen complex undergoes oxidative dehydrogenation under anaerobic conditions to form an imine with the double bond conjugated to the heterocyclic ligand.32... [Pg.216]

Figure 5. Pictorial representation of the linkers used in the aliphatic-based CPs described in the corresponding figure. Figure 5. Pictorial representation of the linkers used in the aliphatic-based CPs described in the corresponding figure.
From the results summarized in Table I, apparently the Brpnsted relationship will hold for all combinations of nucleophiles and electrophiles. Because, as pointed out previously, the Hammett equation is really a special case of the Brpnsted relationship, all the legion of nucleophile-electrophile, rate-equilibrium Hammett correlations that have been studied also fall under the scope of the Brpnsted relationship. For example, nucleophilicities of ArO , ArS , ArC(CN)2 , and the other families listed in footnote c of Table I have generally been correlated by the Hammett equation, where the acidities of benzoic acids in water are used as a model for substituent interactions with the reaction site (a), and the variable parameter p is used to define the sensitivity of the rate constants to these substituent effects. The Brpnsted equation (equation 3) offers a much more precise relationship of the same kind, because this equation does not depend on an arbitrary model and allows rate and equilibrium constants to be measured in the same solvent. Furthermore, the Brpnsted relationship is also applicable to families of aliphatic bases such as carboxylate ions (GCH2C02 ), alkoxide ions (GCH20 ), and amines (GCH2NH2). In addition, other correlations of a kinetic parameter (log fc, AGf, Ea, etc.) can be included with various thermodynamic parameters (pKfl, AG°, Eox, etc.) under the Brpnsted label. [Pg.139]

Makon NF-5 Surfactant Polyoxalkylated aliphatic base surfactant (97% active) Stepan... [Pg.376]

Urethane-modified alkyds are similar to simple alkyds except that dibasic acid is replaced with a difunctional isocyanate such as toluene diisocyanate or hexamethylene diisocyanate. The process is also similar to simple alkyds. Coatings made with urethane-modified alkyds dry faster and harder than alkyds, yet retain flexibility. These systems have better water-, chemical- and abrasion-resistance than alkyd resins, and cost is also relatively low (Wicks et al., 1998). These are used in clear finishes for wood floors, cabinets, OEM, maintenance, and architectural coatings. The aliphatic-based systems are excellent for exterior use, or where UV exposure is possible, while aromatic-based systems usually have better abrasion-resistance. Chemo-enzymatic synthesis of urethane-based systems produces better control of stereochemistry and can impart unique properties (Athawale Bhabhe, 1998 Athawale Gaonkar, 1999 Athawale Joshi, 2000, 2004 Bhabhe Athawale, 1998). [Pg.584]

The value of 11 for ethylamine is representative of aliphatic bases that of 5 for aniline is typical of aromatic bases which are much weaker. As pJ figures are logarithms, there is a difference of one millionfold (i.e. antilog 6) between the strengths of ethylamine and aniline. Many alkaloids and other biologically active bases have values about 8. Bases with values less than 7 scarcely affect neutral indicator paper. [Pg.383]

Butvar Dispersion BR Resin viscosity builder, aliphatic-based coatings... [Pg.1635]


See other pages where Aliphatic bases is mentioned: [Pg.511]    [Pg.511]    [Pg.53]    [Pg.66]    [Pg.67]    [Pg.268]    [Pg.53]    [Pg.66]    [Pg.67]    [Pg.393]    [Pg.393]    [Pg.39]    [Pg.241]    [Pg.248]    [Pg.39]    [Pg.244]    [Pg.251]    [Pg.507]    [Pg.290]    [Pg.290]    [Pg.559]    [Pg.241]    [Pg.1213]    [Pg.384]    [Pg.268]    [Pg.357]    [Pg.1451]    [Pg.1451]    [Pg.1451]    [Pg.1453]    [Pg.1453]    [Pg.1590]    [Pg.1590]    [Pg.1621]    [Pg.1621]    [Pg.245]    [Pg.800]   


SEARCH



Acid-Base Equilibria of Aliphatic Diazo Compounds

Aliphatic Polyester Dendrons and Dendrimers based on 2,2-bis-hydroxymethylpropionic Acid

Aromatic nucleus, aliphatic bases with

Halides, aliphatic base effect

Miscellaneous Bases of Aliphatic Origin

Petroleum-based polyesters biodegradable aliphatic copolyesters

Reactions of Sulfur-Based Nucleophiles with Halogenated Aliphatics

Schiff bases, 434 aliphatic

© 2024 chempedia.info