A study of acridine and acridinium-substituted bis(terpyridine)zinc(ii) and ruthenium(ii) complexes as photosensitizers for O2 ( 1Δg) generation

Abstract

The homoleptic zinc(ii) and ruthenium(ii) metal complexes of bis(tridentate) 9-acridine and 10-methyl-9-acridinium-substituted terpyridines were tested for their suitability as triplet photosensitizers (PS) using the photooxidation of 1,5-dihydroxynaphthalene (DHN) to Juglone as a model reaction. Singlet oxygen (O21Δg) generation is superior or comparable to Ru(bpy)32+ for the acridine complexes, whereas the acridinium complexes are ineffective. The molecular structure of the bis(9-(5-([2,2′:6′,2′′-terpyridin]- 4′-yl)thien-2-yl)-10-methylacridinium)zinc(ii) complex ([Zn(MeATT) 2][PF6]4) is determined by X-ray structure analysis, whereas for other complexes DFT calculations were performed for structural parameters to obtain insights into their electronic properties. © The Royal Society of Chemistry and Owner Societies.