Electron donating property

The roles of phosphines are not clearly understood and are unpredictable. Therefore, in surveying optimum conditions of catalytic reactions, it is advisable to test the activity of all these important types of phosphines and phosphites. which have different steric effects and electron-donating properties. 

The order of reactivity of carboxylic acid derivatives toward nucleophilic acyl sub stitution can be explained on the basis of the electron donating properties of sub stituent X The greater the electron donating powers of X the slower the rate... 

Unlike common commercial dianhydrides such as PMDA and BTDA, bis(ether anhydride)s possess moderate reactivity toward nucleophiles because of the electron-donating property of the ether groups. Bis(ether anhydtide)s are hardly affected by atmospheric moisture. The stabiUty and generally better solubiUty of bis(ether anhydtide)s provide significant advantages in manufacturing operations. 

The enzyme catalyzes the hydrolysis of an amide bond linkage with water via a covalent enzyme-inhibitor adduct. Benzoxazinones such as 2-ethoxy-4H-3,l-benzoxazin-4-one [41470-88-6] (23) have been shown to completely inactivate the enzyme in a competitive and stoichiometric fashion (Eigure 5). The intermediate (25) is relatively stable compared to the enzyme-substrate adduct due to the electron-donating properties of the ortho substituents. The complex (25) has a half-life of reactivation of 11 hours. 

Kitajima and Tolman have provided estimates of the relative electron-donating properties of poly(pyrazolyl)borato ligands based upon comparisons of the observed p(CO) stretching frequencies of sev-... 

The poly(cyclodiborazane)s containing a dithiafulvene unit in the backbone were also reported (scheme 25).38 This polymer showed an efficient extension of conjugation between the consecutive repeat units due to the strong electron donating property of the dithiafulvene unit. Before doping, this polymer exhibited an electrical... 

The thermal decomposition of dibenzyl was not affected by the addition of phenol or p-cresol. In contrast, the decomposition of 2,2 -dinaphthyl ether increases remarkably in the presence of phenolic compounds as shown in Table III, and the effect seems to increase with increasing the electron donating property of substituent on the benzene nucleus. 

Many inorganic species show charge-transfer absorption and are called charge-transfer complexes. For a complex to demonstrate charge-transfer behavior one of its components must have electron donating properties and another component must be able to accept electrons. Absorption of radiation then involves the transfer of an electron from the donor to an orbital associated with the acceptor . ... 

It is important to note that the strong electron-donating properties of diphenylphosphinoferrocene are able to stabilize the central iridium atom in the unusual 0 and —I oxidation states. 

The electronic properties of n-conjugated polymers reflect well the basic electron-withdrawing or electron-donating properties of the components of the Ti-conjugated polymer [62]. In view of the electrochemical reduction potential, the thiophene unit and tetrathiafulvalene unit (Nos. 8 and 9 in Table 1) have a similar electronic effect in PAEs. It is reported that poly(arylenevinylene)s are also susceptible to electrochemical reduction [63, 64]. Due to the electron-accepting properties, PAEs are usually inert in electrochemical and chemical (e.g.,by I2 [54]) oxidation. 

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