Chlorination charge-transfer complex

Charge-Transfer Compounds. Similat to iodine and chlorine, bromine can form charge-transfer complexes with organic molecules that can serve as Lewis bases. The frequency of the iatense uv charge-transfer adsorption band is dependent on the ionization potential of the donor solvent molecule. Electronic charge can be transferred from a TT-electron system as ia the case of aromatic compounds or from lone-pairs of electrons as ia ethers and amines. 

In the case of tertiary N-ethylamine derivatives the N-ethyl group is first selectively oxidized by p-chloranil to an enamino group which then condenses with excess p-chloranil to a blue aminovinylquinone derivative [7]. Secondary N-ethyl derivatives do not yield blue aminovinylquinone derivatives they probably react directly with chloranil by nucleophihc attack at one of the four chlorine atoms to yield aminoquinones of other colors [7], It has also been suggested that some classes of substances react to yield charge transfer complexes [1, 5, 8, 12],... 

The kinetics of the chlorination of phenol and 2-naphthol by l,3-dichloro-5,5-dimethylhydantoin (2) in aqueous acidic media have been interpreted10 in terms of an initial rate-limiting formation of a charge-transfer complex between the substrate and the chlorinating agent. A kinetic study of the chlorination of nine aryl ethers by 1-chlorobenzotriazole in acetic acid has also led to mechanistic conclusions.11... 

The reaction of tetrasilabutadiene 64 with Cl2 gives 1,2,3,4-tetrachlorotetrasilane 182 [Eq. (86)].125 As chlorine gas is added, the solution of 64 turns from dark red to blue-black to orange, and finally to colorless. On this basis, the addition is proposed to proceed stepwise via the initial formation of a charge-transfer complex between 64 and Cl2 to give 183, which is converted to disilene 184 and then to 182 by the addition of a second molecule of Cl2. 

Chloromethylated polystyrene and chloromethylated poly(a-methyIstyrene) are negative type resists having high sensitivity and high resolution. In the pulse radiolysis of solid films of this polymer, the absorption spectra of substituted benzyl-type polymer-radical and the charge transfer complex between phenyl rings and chlorine atoms were observed (Fig. 17) [59], The benzyl-type radical may be produced by the dissociative electron attachment to the benzyl part of chloromethylated polystyrene (CMS). 

Good evidence for the formation of charge-transfer complexes comes from the isolation and structure determination of solids. Chlorine and Br2, as well as the interhalogens IBr and Id, have been found to behave similarly to iodine. Some examples of crystal structures are ... 

Legon, A. C., Lister, D. G., and Thom, J. C., Non-reactive interaction ofantmonia and molecular chlorine Rotational spectrum of the charge-transfer complex NHf ClJ. Chem. Soc. Faraday Trans. 90, 3205-3212 (1994). 

The UV spectrum of ferrocene in CCl. contains a new strong and broad absorption band in the wavelength region from 300 to 390 nm (60,61). This new band is due to a charge-transfer complex formed between ferrocene and CCl (62,63) The iron atom serves as an electron donor and the chlorine atom as an electron acceptor. Under U7-irradiation the photochemical dissociation of this charge-transfer complex takes placet... 

Perrocene may accelerate the embrittlement of chlorinated polymers (64). This mechanism also involves a charge-transfer complex wiTE a C-Cl bond in PPC and ferrooene. The formation cation,chloride ion and a polymer macroradical are formedt... 

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