Tetrabutylammonium perchlorate, effect

In some systems it is necessary to add a large amount of salts to obtain polymers with low polydispersities. This happens when salts participate in ligand/anion exchange (special salt effect) and when they enhance ionization of covalent compounds through the increase of ionic strength. The special salt effect may either reduce or enhance ionization. Strong rate increases observed in the polymerization of isobutyl vinyl ether initiated by an alkyl iodide in the presence of tetrabutylammonium perchlorate or triflate can be explained by the special salt effect [109]. The reduction in polymerization rate of cyclohexyl vinyl ether initiated by its HI adduct in the presence of ammonium bromide and chloride can be also ascribed to the special salt effect [33]. The breadth of MWD depends on the relative rate of conversion of ion pairs to covalent species and is affected by the structure of the counterions. 

The counterion employed also has a marked effect on the electropolymerization process in organic solvents. For example, the polymerization of poly(methyl carboxypyrrole) (PMCP) proceeds differently in para-tolucncsul Ionic acid (pTS), tetrabutylammonium perchlorate (TBAP), tetrabutylammonium tetrafluoroborate (TBABF4), and tetrabutylammonium hexafluorophosphate (TBAPF6).63 As reported in that work, the rate of polymerization (at constant potential) and the time required for the onset of polymer deposition varied with the counterion employed. 

PVB, tetrabutylammonium perchlorate (TBAP), imidazole (Imz) or PEG2000 were employed as host polymer, salt and additive for the polymer electrolyte. Imz or PEG2000 are the molecules that are effective in forming an ionic conduction pathway above its melting temperature. TBAP also has a character of melting. ... 

The detrimental effect of tetrabutylammonium iodide and tetrafluoroborate on the rate of polymerisation of styrene in the presence of acetyl perchlorate can easily be ex-plaiited by an anion-exchange reaction with the propagating esta to give a much less active chain carrier. 

The electropolymerization of ferrocene/thiophene conjugates [65] was conducted by oxidation on a Pt electrode and led to the deposition of a monolayer of poly (thiophene). The electropolymerization was performed from several solution systems, such as tetrabutylammonium hexafluorophosphate/acetonitrile and lithium perchlorate/acetonitrile, at a concentration of 0.1 M. Constant potential experiments (+ 2.0 V) for a definite time were used to effect polymerization. Polymerization was also attempted using cyclic voltammetry (repeatedly sweeping from 0.0 to + 2.5 V) and pulse potential (potential stepped from 0.0 to 2.0 V and back to 0.0 V). 

As to acceleration of the isomerization, addition of salts such as lithium perchlorate in acetonitrile solution and tetrabutylammonium tetrafluoro-borate in dichloromethane in DCA-sensitized irradiation of cis-stilbene enhanced the isomerization. A salt effect is probably responsible for retardation of recombination between the resulting stilbene radical cations and counteranions (DCA--, etc.) [143, 146]. 

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