| Title | 1,4-Bis(phosphine)-2,5-difluoro-3,6-dihydroxybenzenes and their P-oxides: Syntheses, structures, ligating and electronic properties. |
| Publication Type | Journal Article |
| Year of Publication | 2008 |
| Journal | Journal of Organometallic Chemistry |
| Volume | 693 |
| Issue | 20 |
| Pagination | 3263 - 3272 |
| Authors | Pignotti, Louis R., Natcharee Kongprakaiwoot, William W. Brennessel, Jonas Baltrusaitis, Rudy L. Luck, and Eugenijus. Urnezius |
| Publisher | Elsevier Ltd. |
| ISBN Number | 0022-328X |
| Keywords | crystal structure diphosphine phosphine oxide hydroxyphenyl fluoro difluorohydroquinone, frontier orbital diphosphine hydroxyphenyl fluoro difluorohydroquinone, mol structure diphosphine phosphine oxide hydroxyphenyl fluoro difluorohydroquinone, nickel chelate complex hydroxyphenylphosphine difluorohydroquinone diphosphine bridged prepn, oxidn potential diphosphine phosphine oxide hydroxyphenyl fluoro benzenediol difluorohydroquinone, phosphine diphosphine hydroxyphenyl fluoro difluorohydroquinone prepn structure |
| Abstract | Difluorinated p-diphosphino-1,4-benzenediols 2,5-F2-3,6-(R2P)2C6(OH)2-1,4 (2a,b; R = Ph, iPr), their nickel chelate P,O-complexes, and P,P'-dioxides (3a,b; R = Ph, iPr) were prepd. and characterized. Reactions of 1,4-difluoro-2,5-dimethoxybenzene with LDA (1:2) at low temps. generated organodilithio intermediates; quenching the reaction mixts. with chlorophosphines ClPR2 produced 1,4-(R2P)2-2,5-difluoro-3,6-dimethoxybenzenes (1a,b; R = Ph, iPr). Demethylation of 1a-b was accomplished by BBr3, yielding bis(phosphino)hydroquinones 2a-b. Treating 2a-b with excess hydrogen peroxide produced bis(phosphinyl)hydroquinones 3a-b. The binucleating properties of 2a were established by the formation of a bimetallic nickel complex upon reaction with Ph2Ni(PMe3)2. Electrochem. activity of hydroquinones 2a-b and 3a-b was examd. by cyclic voltammetry. In addn., compds. 2a, 3a and 3b were obtained in cryst. form and characterized by single-crystal x-ray diffraction. The influence of the fluorine substituents on the compn. of the frontier orbitals of 2a and 3a was examd. by computational methods. [on SciFinder(R)] |