Di- and Triferrocenyl (Hetero)Aromatics: Synthesis, Characterization, (Spectro-)Electrochemistry, and Calculations
摘要:
A series of di- and triferrocenyl (hetero)aromatics including 2,5-diferrocenylpyridine (4), 2,6-diferrocenylpyridine (5), 1,3,5-triferrocenylbenzene (9), 2,4,6-triferrocenylpyridine (10), and 2,4,6-triferrocenyl-1,3,5-triazine (11) have been prepared using the Negishi C,C cross-coupling protocol. Characterization of the molecules was performed by spectroscopic means and single-crystal X-ray diffraction study (10). The electrochemical properties of these compounds were determined by cyclic voltammetry, square wave voltammetry, and in situ NIR spectroelectrochemistry. The cyclic voltammograms show well-defined, separated, and reversible one-electron processes for each ferrocenyl moiety with Delta E degrees' values (= separation between two formal potentials) ranging from 140 to 185 mV. The UV-vis/NIR spectra of the partially oxidized mixed-valent complexes of 4, 5, 9, and 10 show weak intervalence charge transfer absorptions, while only electrostatic interactions exist between the different oxidized iron centers of 11. Supporting DFT calculations were carried out to establish a basic understanding of the electronic structure.
Di- and Triferrocenyl (Hetero)Aromatics: Synthesis, Characterization, (Spectro-)Electrochemistry, and Calculations
摘要:
A series of di- and triferrocenyl (hetero)aromatics including 2,5-diferrocenylpyridine (4), 2,6-diferrocenylpyridine (5), 1,3,5-triferrocenylbenzene (9), 2,4,6-triferrocenylpyridine (10), and 2,4,6-triferrocenyl-1,3,5-triazine (11) have been prepared using the Negishi C,C cross-coupling protocol. Characterization of the molecules was performed by spectroscopic means and single-crystal X-ray diffraction study (10). The electrochemical properties of these compounds were determined by cyclic voltammetry, square wave voltammetry, and in situ NIR spectroelectrochemistry. The cyclic voltammograms show well-defined, separated, and reversible one-electron processes for each ferrocenyl moiety with Delta E degrees' values (= separation between two formal potentials) ranging from 140 to 185 mV. The UV-vis/NIR spectra of the partially oxidized mixed-valent complexes of 4, 5, 9, and 10 show weak intervalence charge transfer absorptions, while only electrostatic interactions exist between the different oxidized iron centers of 11. Supporting DFT calculations were carried out to establish a basic understanding of the electronic structure.
Metallocene-substituted pyridyl amines, their metal complexes, and processes for production and use thereof
申请人:ExxonMobil Chemical Patents Inc.
公开号:US07858817B2
公开(公告)日:2010-12-28
This invention relates to new transition metal complexes for use in olefin polymerization and oligomerization. The active complex is a pyridine amide having a metallocenyl substituent as part of the ligand structure. The invention also relates to novel precursors for the ligand systems of such complexes obtained from metallocenyl-substituted pyridine compounds through sequences involving addition-condensation or lithium-halogen exchange (with subsequent metathesis) reactions.