Donicity

Hydrocinnamic Acid.—The preparation illustrates the use of sodium amalgam as a reducing agent It should be noted that hydiocinnamic acid may be also obtained from m.donic ester by acting upon the sodium compound nith benzyl chloride, then hydrolysing and removing carbon dioxide,... 

Prostaglandin (Section 27.4) A lipid derived from arachi-donic acid. Prostaglandins are present in nearly all body tissues and fluids, where they serve many important hormonal functions. 

Donicity of reactants Electron donor Electron acceptor 3 /fl0n< ) A 5 /5G X) ... 

Dennery, P.A., Kramer, C.M. and Alpert, S.E. (1989). Thiobarbiturate-reactive substances and activation of arachi-donic acid cascade in cultured rabbit tracheal epithelial cells exposed in vitro to hyperoxia. Am. Rev. Resp. Dis. 139, A42. 

TRPV4 was identified a decade ago as an osmotransducer that is expressed in lung, heart, kidney, airway muscle cells, sensory neurons, brain, skin, gut, sympathetic nerves, inner ear, endothelium, and fat tissue [58-61]. TRPV4 is activated by heat (27-34°C), endogenous substances such as anandamide (59, AA) and the arachi-donic acid metabolite 5,6-epoxyeicosatrienoic acid (60, 5,6-EET), a plant dimeric diterpenoid bisandrographolide A (61, BAA), and the semisynthetic phorbol ester 4a-phorbol-12,13-didecanoate (62, 4a-PDD) [62],... 

As mentioned earlier, oxidation of LDL is initiated by free radical attack at the diallylic positions of unsaturated fatty acids. For example, copper- or endothelial cell-initiated LDL oxidation resulted in a large formation of monohydroxy derivatives of linoleic and arachi-donic acids at the early stage of the reaction [175], During the reaction, the amount of these products is diminished, and monohydroxy derivatives of oleic acid appeared. Thus, monohydroxy derivatives of unsaturated acids are the major products of the oxidation of human LDL. Breuer et al. [176] measured cholesterol oxidation products (oxysterols) formed during copper- or soybean lipoxygenase-initiated LDL oxidation. They identified chlolcst-5-cnc-3(3, 4a-diol, cholest-5-ene-3(3, 4(3-diol, and cholestane-3 3, 5a, 6a-triol, which are present in human atherosclerotic plaques. 

In transfected cells, H3 receptor mediated activation of Gj/0 proteins has also been reported to modulate arachi-donic acid release [29] and the Na+/H+ exchanger [44], and to inhibit Ca2+ influx and exocytosis of [3H] noradrenaline from transfected SH-SY5Y-H3 cells [45], The inhibition of Ca2+ influx may be particularly relevant in view of the known physiological function of the brain H3 receptor. 

Starting from Equation 10.32, Perez et al. [21] defined spin-donicity and spin-philicity. Following a variational calculation, as used by Parr et al. [22] to define the electrophilic power, they obtain, for the maximum change in energy (AZsmax) when the system modifies its spin number from Ns to Ns + AiVs in a reservoir of spins, ... 

In the direction of decreasing spin multiplicity (A1VS < 0), the spin-donicity can be defined as... 

A large spin-donicity number is expected when the energy difference is smaller between the triplet and singlet states. Thus, spin-philicity and spin-donicity are also a measure of the energy differences between singlet and triplet states, furthermore, it has been demonstrated the applicability of these reactivity indexes in the prediction of the spin transfer observed in the spin-catalysis phenomenon [21], Equivalent quantities at fixed Ns ([Pg.150]

Spin potential, spin hardness, spin-donicity, and spin-philicity indexes have also been applied successfully to other specific problems [19,23,24]. 

There is no more research on the analysis or applications of SP-DFT generalized Fukui functions, per se. Instead, condensed-to-atoms SP-DFT Fukui function schemes have been developed and applied to different chemical reactivity problems. In these schemes, the information of the Fukui functions is condensed on an atomic position. In addition, the Fukui function/ (r) is related with the extension of global to local spin-donicity and spin-philicity, defined as [20]... 

Olah, J., De Proft, F., Veszpremi, T., and Geerlings, P. 2004. Spin-philicity and spin-donicity of substituted carbenes, silylenes, germylenes, and stannylenes. J. Phys. Chem. A 108 490-499. 

Perez, P., Andres, J., Safont, V.S., Tapia, O., and Contreras, R. 2002. Spin-philicity and spin-donicity as auxiliary concepts to quantify spin-catalysis phenomena. J. Phys. Chem. A 106 5353-5357. 

We discussed mainly some of the possible applications of Fukui function and local softness in this chapter, and described some practical protocols one needs to follow when applying these parameters to a particular problem. We have avoided the deeper but related discussion about the theoretical development for DFT-based descriptors in recent years. Fukui function and chemical hardness can rigorously be defined through the fundamental variational principle of DFT [37,38]. In this section, we wish to briefly mention some related reactivity concepts, known as electrophilicity index (W), spin-philicity, and spin-donicity. 

These indices have been used to study the reactivity for a series of chlorobenzenes and a good correlation is observed, for example, between W and toxicity of chlorobenzene [41]. For a detail discussion of this concept and its applications, we refer the readers to a recent review [41,42]. For studying intramolecular reactivity, these philicity indices and local softness contain the same information as obtained from the Fukui functions, because they simply scale the Fukui functions. In some cases the relative electrophilicity and relative nucleophilicity may be used although they provide similar trends as s(r) and co(r) in most cases [43]. In the same vein, the spin-donicity and spin-philicity, which refer to the philicity of open-shell systems [44], could also be utilized to unravel the reactivity of high-spin species, such as the carbenes, nitrenes, and phosphinidenes [45]. 

Gutmann introduced3 the concepts of donor number (donicity) and acceptor number (acceptivity), as dimensionless numbers, for the characterization of donor properties of bases independently of the solvent. 

In this way, the concept of donicity explains some properties of substances usually defined apolar from their usual parameters of polarity (dielectric constant, dipolar moment, Et parameter value) but which presents high possibilities of interaction (and of solvatation) with positively charged centres. This is the case of tertiary amines such as triethylamine (or of ethers such as THF, dioxane) which shows usual polarity parameters near that of apolar solvents (benzene, chloroform, chlorobenzene, 1,2-dichloroethane, etc.) but high ability to coordinate positive charges. 

The main consequence of EDA interactions between solvents of high donicity and nitroarenes is that amines in benzene (or in other similar solvents) compete with the solvents in complexing the nitroarenes253,254. This fact explains the ratio jfcchlorofornyjfcbenzene ] 0 or qlc molecular complex between aniline and FDNB (see Table 1). 

---