Hypovalent titanium and Ti(II)-Ti(III) interconversions

Dhar, BB; Gould, ES

HERO ID

5416298

Reference Type

Journal Article

Year

2010

Language

English

PMID

20104325

HERO ID 5416298
In Press No
Year 2010
Title Hypovalent titanium and Ti(II)-Ti(III) interconversions
Authors Dhar, BB; Gould, ES
Journal Dalton Transactions (Online)
Volume 39
Issue 6
Page Numbers 1616-1619
Abstract Treatment of pink titanium(iii) triflate (0.045 M) with HF in triflic acid (CH(3)SO(3)H) converts Ti(iii) rapidly to a 1 : 1 mixture of Ti(IV) and green Ti(II): (2 Ti(III) + 4 HF --> TiF(4) + Ti(II) + 4 H(+)). This disproportionation is half complete when [HF] added is 0.027 M. Substituted 1,4-benzoquinones are reduced rapidly by Ti(iii) in the absence of fluoride, yielding straightforward logarithmic curves, but reactions of the same quinones with Ti(ii) in fluoride media exhibit more complex profiles, the major portions of which are zero order in oxidant. These reactions are strongly catalyzed by added Ti(iv). Analyses of complex curves are consistent with a reaction sequence initiated by Ti(ii)-Ti(iv) disproportionation, forming Ti(iii), which reacts with the quinone, yielding the quinhydrone, QH . The latter is rapidly reduced by Ti(ii). Values of rate constants obtained from these analyses are in agreement with those for reductions of quinones by Ti(iii), in the absence of fluoride.
Doi 10.1039/b914989a
Pmid 20104325
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English