The synthesis and characterisation of novel ferrocenyl polyphenylenes

Abstract

This work describes the synthesis and characterisation of a new series of polyphenylenes with up to four ferrocenyl moieties. The synthetic route involves the preparation of a number of novel precursors. Cyclopentadienones, generated from the two-fold Knoevenagel condensation of di-ferrocenyl propanones and diketones, are used in [2 + 4] Diels-Alder cycloadditions with appropriately substituted acetylenes. 13 is amongst the compounds isolated. It is the largest ferrocenyl-supported polyaromatic hydrocarbon (PAH) to date. Prepared via a Sonogashira cross-coupling reaction between ethynyl-Fc and iodo-HBC, it comprises a hexa-peri-hexabenzocoronene (HBC) core linked via acetylene to a ferrocenyl unit (Fc). The electrochemical and absorption properties of the ferrocenyl-polyphenylenes and the fully conjugated 13 are discussed. The NLO data for 13, determined by hyper Rayleigh scattering techniques, are compared to those of similar fulleryl-based compounds in the literature.

Azulene‐Based Donor–Acceptor Systems: Synthesis, Optical, and Electrochemical Properties

“…[55] The absorption band of 46 was ascribed to the quinoid resonance structure in the azulene moiety [43] in conjugation with the 2amino group, similar to that of TCBDs 22 and 28. [55] The absorption band of 46 was ascribed to the quinoid resonance structure in the azulene moiety [43] in conjugation with the 2amino group, similar to that of TCBDs 22 and 28.…”

Luminescent Bis‐Cyclometalated Gold(III) Complexes with Alkynyl Ligands of Hexaphenylbenzene and Hexabenzocoronene Derivatives and Their Supramolecular Assembly

“…On the other hand, the electronic absorption spectrum of complex 8,w hich possesses ap olycyclic aromatic HBC core in the alkynyl ligand, shows typical absorption features to those showni no ther HBC transition-metal complexes (a band at l = 448 nm;pband at l = 396 nm, and b band at l = 364 nm). [57][58][59][60]64] The absorption bands in 8 show slight redshifts relative to those in the free HBC-alkynyl ligand due to extension of p conjugation in the alkynyl ligand after the incorporation of the bis-cyclometalated gold(III) moiety. [59] The s donation from the alkynyl group to the gold(III) center may also contributet ot he redshifts observed in the HBC-alkynylgold(III) complex.…”

Facile synthesis, characterisation and anti‐inflammatory activities of ferrocenyl ester derivatives of 4‐arylidene‐5‐imidazolinones

“…The high‐energy band with maxima at about 356 nm corresponds to the π → π * electronic transition of the ligand ( 5a–7a ), and the low energy band at about 369 nm might arise from the localised metal‐to‐ligand charge transfer [Fe(d) → Cp( π *)] transition ( 7b–8b ). The presence of a low‐energy band confers the yellow colour for the conjugates . Because the ferrocene moiety also depicts the metal‐to‐ligand charge transfer (MLCT) band between 320 and 360 nm, the low‐energy band might also possess some ferrocene character .…”