Iodine-amine complex

Treatment with chlorine gas converts amines to chloramines, whose active chlorine oxidizes iodide to iodine. This then forms the well-known, deep blue iodine-starch complex [13]. 

Morishima and coworkers30 have studied the CT complexes of iodine with various cyclic and bicyclic amines containing non-adjacent double bonds or aromatic rings. They could show that the iodine-amine CT absorption is a useful means of assigning the ionizations in the PE spectra of amines. 

ROH - RI,1 Reaction of I2 (1 equiv.) with BH3 QHsNfCjHsJj provides a diiodoborane amine complex in situ that converts alcohols into alkyl iodides in 62-86% yield. It also effects reductive iodination of carbonyl compounds. 

Blit amine complex.2 Reaction of BH3 C6H5N(C2H5)2 with 1.5 equiv. of iodine provides an amine complex of BI3. This complex when combined with acetic acid liberates hydroiodic acid, which undergoes Markovnikov addition to alkenes and alkynes in good yield. 

A number of related amine complexes [PdCUL<2] have been prepared by similar methods (L = MeNH2, piperidine,NMes, 1-phenylethylamine, pyridine,a-picoline L = bipy, phen, 2,9-dimethyl-1,10-phenanthroline, biguanidine).The pyridine complex has also been formed by NOCl oxidation of [PdCl2py2]- These workers also reported the synthesis of [Pdl2Cl2py2] via iodine oxidation of the chloropalladium(II) analogue. 

The highest conductivities thus far observed in organic molecules are found among the donor-acceptor complexes. The activation energies for conduction are small, on the order of 0.1 eV ( 2 kcal) or less. Examples are the complexes of aromatic hydrocarbons with iodine and complexes of amines with chloranil or related quinones. The best conductors have a high free-radical content and are usually not of simple stoichiometry. The complex salts of TCNQ ° (I) are the best of the known organic conductors. The... 

Many studies indicate qualitatively that electrophilic iodination of aromatic amines in the presence of persulfate , mercuric oxide , acetic acid , iodine bromide , complexing reagents , and without solvent and catalyst , yield ortho and/or para products as expected from the -I- R effect of the amino group. 

Haas, J., Bissmire, S. and Wirth, T. (2005) Iodine monochloride-amine complexes an experimental and computational approach to new chiral electrophiles. Chem. Ear. 7., 11,5777-5785. 

As a possible mechanism (Scheme 7.3b), the amine abstracts iodine from Polymer-I to generate Polymer and a complex of the iodine radical and amine (I /amine complex). Since the iodine radical is not a stable radical, it recombines with another iodine radical to form a complex of the iodine molecule and amine (12/amine complex). Polymer reacts with these complexes (deactivators) to form Polymer-I and the amine. In this process, electron transfer from the amine to iodine would occur to a range of different degrees including full (redox), partial (coordination) and nearly no transfer, depending on the kind of amines. The process is reversible complexation (RC) of iodine and catalyst, and the polymerization is termed RC mediated polymerization (RCMP). °° Clearly, it is mechanistically distinguished from both ATRP and RTCP. 

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. 

Another route to the amido complexes originates from [(>j-Tp )W(CO) (PhC=CMe)(OTf)l and benzylamine and yields [(i -Tp )W(CO)(PhC=CMe) (NHCH2Ph)] (96JA6916). The latter can be protonated with tetrafluoroboric acid to give the amine derivative [(> -Tp )W(CO)(PhC=CMe)(NH2CH2Ph)](Bp4), and this process can be reversed by -butyllithium. Hydride abstraction by silver tetrafiuoroborate, molecular iodine, or PhsCPEe leads to the cationic imine derivatives [(> -Tp )W(CO)(PhC=CMe)(HN=CHPh)]". -Butyllithium deproto-nates the product and gives the neutral azavinylidene species [(> -Tp )W(CO) (PhC=CMe)(N=CHPh)]. The latter with silver tetrafiuoroborate forms the cationic nitrile species [(j -Tp )W(CO)(PhC=CMe)(N=CPh)](Bp4). 

Primary and secondary amines and amides are first chlorinated at nitrogen by the chlorine released by the gradually decomposing calcium hypochlorite. Excess chlorine gas is then selectively reduced in the TLC layer by gaseous formaldehyde. The reactive chloramines produced in the chromatogram zones then oxidize iodide to iodine, which reacts with the starch to yield an intense blue iodine-starch inclusion complex. 

Amine-borane complexes are not very reactive toward hydroboration, but the pyridine complex of borane can be activated by reaction with iodine.160 The active reagent is thought to be the pyridine complex of iodoborane. 

Among the most important indirect methods of analysis which employ redox reactions are the bromination procedures for the determination of aromatic amines, phenols, and other compounds which undergo stoichiometric bromine substitution or addition. Bromine may be liberated quantitatively by the acidification of a bromate-bromide solution mixed with the sample. The excess, unreacted bromine can then be determined by reaction with iodide ions to liberate iodine, followed by titration of the iodine with sodium thiosulphate. An interesting extension of the bromination method employs 8-hydroxyquinoline (oxine) to effect a separation of a metal by solvent extraction or precipitation. The metal-oxine complex can then be determined by bromine substitution. 

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