Synthesis, Structure, and Redox Chemistry of Ethenyl and Ethynyl Ferrocene Polyaromatic Dyads

Abstract

A series of ferrocenyl-arene dyads, Fc-CtC-Ar, trans-Fc-CHdCH-Ar, and Fc-CHd CH-CHdCH-Ar (Ar ) phenyl, 1-naphthyl, 2-naphthyl, 9-phenanthryl, 9-anthryl, 1-pyrenyl, 3-perylenyl) have been synthesized. Their structures and spectroelectrochemical properties are discussed. The molecular structures of several have been determined by X-ray diffraction and the observed structures compared with global free-energy minimized calculated structures. In the solid state all ethynyl dyads have the aromatic ring orthogonal to the ferrocenyl cyclopentadienyl rings, whereas calculations predict a coplanar orientation. Calculated and observed structures agree for the ethenyl dyads with the rings orthogonal and coplanar for the anthryl and pyrenyl dyads, respectively. In most cases the solid-state structures are stabilized by offset π-stacking interactions between the polycyclic hydrocarbon rings. The two bands in the electronic spectra of the neutral dyads are due to the individual aryl and ferrocenyl end-groups. Upon oxidation at the [Fc] +/0 couple, the ferrocenyl transition is replaced by LMCT bands at lower energy and a new weak band in the NIR assigned to a Fc + r aryl transition; these assignments are supported by resonance Raman spectra, and the energy of the Fc + r aryl transition correlates with the ionization energy of the aryl group. These are therefore electrochromic dyads.

Aldol condensation reactions of [Co(η4-C4Ph4){η5-C5H4C(O)CH3}]

“…The terminal Ph-C-H moieties of the butadiene ligand are not coplanar with the C(1)-C(4) plane but make dihedral angles of 33.7°and 35.4°with it so that both Ph groups adopt the exo configuration and are tilted towards the cyclopentadienyl ligand. In contrast, the ipso C atoms of the central Ph groups lie close to the C(1)-C(4) plane though the rings are tilted with respect to it by 64.0°for C(11) and 77.3°for C (17). The Co-C(butadiene) distances are 2.0594(15)/2.0485(15) Å to the outer C atoms and 1.9911 (15) …”

“…Although the non-planarity in the case of 3d, 3e, 3h and 3i may be a consequence of crystal packing forces, it seems reasonable to assume that for 3k the distortions are due to intramolecular steric interactions between the anthracenyl group and the C(36) hydrogen atom on one hand, and the phenyl groups of the C 4 Ph 4 ligand on the other. In a related complex Fe(g 5 -C 5 H 5 )(g 5 -C 5 H 4 -CH@CH-9-anthracenyl) similar anthracene-alkene steric interactions are relieved by rotation about the C-C bond joining them so that there is an angle of 62.58 (14)°between alkene and anthracene planes [17]. The presence of the phenyl groups of the tetraphenylbutadiene ligand prevents this in 3k.…”

The spectra, structures and electrochemistry of Ni(η5-C5H5)(PPh3)–CC–Ar complexes, and their reactions with Co2(CO)8

“…Although the results reported for 1a were not encouraging [3], there was the possibility that more highly annelated PAH end-groups would prove to be better acceptors than Ph. Furthermore, our electrochemical/OTTLE studies on a series of Fc-C"C-Ar (Fc = ferrocenyl) derivatives showed they, or more particularly their [Fc-C"C-Ar] + derivatives, have unusual spectroscopic properties [5], which might also be found in their Ni(g 5 -C 5 Consequently we prepared a series of Ni(g 5 -C 5 H 5 ) (PPh 3 )-C"C-Ar complexes 1, where Ar = (a) C 6 H 5 , (b) 4-PhC 6 H 4 , (c) 1-C 10 H 7 (1-naphthyl), (d) 2-C 10 H 7 (2-naphthyl), (e) 9-C 14 H 9 (9-phenanthryl), (f) 9-C 14 H 9 (9-anthryl), (g) 3-C 16 H 9 (3-pyrenyl), (h) 1-C 20 H 11 (1-perylenyl), (i) 2-C 4 H 3 S (2-thienyl), and (j) C 10 H 9 Fe (ferrocenyl). They have been characterised by spectroscopic and electrochemical data, and the molecular structures of a number of them determined by X-ray diffraction.…”

Luminescence and Electrochemical Properties of Organostannoxane Coordination Polymer Based on Ferrocenyl-2-Cyano Carboxylate Ligand

“…4), which bounce be deferring a high-energy ligand-centred π-π * electronic transition. In initiation, a weaker absorption band in the visible region was observed at 515 nm respectively, which is to be found another localized excitation formed by two roughly degenerated transitions, and Fe(II) d-d transition or metal-ligand charge transfer (MLCT) process [15,16].…”