Propellers and Planes: Phosphorescent Pt^II σ‐Acetylides from Polyaromatic Ligands

Abstract

This article details the preparation, photophysical and electrochemical investigation of four novel polyaromatic squareplanar platinum(II) bis(acetylide) complexes, incorporating either a planar hexa-peri-hexabenzocoronene (L 2 ) or its uncyclised ethynyl-hexaphenylbenzene precursor (L 1 ). Complexes in both cis and transwere successfully prepared and fully characterised. The low-energy bands of the UV/Vis absorption spectra for the uncyclised family (L 1 , C 1 , T 1 ) and for

Terpyridine-fused polyaromatic hydrocarbons generated via cyclodehydrogenation and used as ligands in Ru(ii) complexes

“…For 4, absorptions related to the π-π* transitions of the planar aromatic platform are shifted to longer wavelengths (around λ 371 nm), as is typical for HBC-type compounds and are broadened and less structured due to enhanced aggregation effects. 10,11 Ru(II) complexes 6, 7 and 8 show a number of ligand-centred π-π* bands at higher energy wavelengths and a lower energy MLCT (d-π*) transition at around λ 485 nm (Fig. 5).…”

“…Recently, organometallic complexes of HBC have been generated via π-coordination of a {Rh(P i Bu 3 ) 2 } + fragment, bound η 6 to an outer aromatic ring, 9 and σ-coordination of a Pt(II) acetylide to two aromatic HBC platforms. 10 The preparation of allcarbon HBCs which bear substituent tridentate ethynyl-terpy ligands has been achieved 11 and incorporating bidentate nitrogen-based binding sites into PAHs is a recent, though synthetically challenging, advance in the generation of new luminescent materials. 12,13 In this new work, we hoped to combine the photophysical properties of the [Ru(terpy) 2 ] 2+ fragment with that of a PAH.…”

“…6 In this way two essentially isoenergetic triplet excited states would be provided: a 3 MLCT ([Ru(terpy) 2 ] 2+ , λ ∼ 629 nm) 14,15 and a HBC-localised 3 ππ* excited state (HBC, λ ∼ 578 nm). 10,16,17 Excitation into one of these might then give rise to efficient energy equilibration between the two complementary energy levels and substantially prolong the excited state lifetimes. Terpy units have also been shown to be effective synthetic platforms on which to introduce dithiocarbamates as highly stable and robust anchoring units for attachment to Au surfaces.…”

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

“…Despite recent reports on related HBC‐ and HPB‐containing isoelectronic platinum(II) complexes, which focused on photophysical property studies of the platinum(II) systems, corresponding supramolecular assembly studies of the platinum(II) complexes have not been made . Therefore, supramolecular assembly studies on HBC‐ and HPB‐containing gold(III) complexes would be an interesting area to explore.…”

The synthesis and characterisation of novel ferrocenyl polyphenylenes

“…Known examples include Bunz's cobalt-containing ethynylated cyclobutadienes, 4-6 η 6 -tricarbonyl chromium 7 and η 6 -[Rh(COD)] + hexa-peri-hexabenzocoronene (HBC) 8 and HBCs incorporating σ-bonded Pt(II) acetylides. 9 To date there are just two compounds reported where ferrocene is attached to an all-benzenoid PAH, one of which comprises four fused benzene rings, 3 the other eight ( Fig. 1).…”