S. Muise, H. Severin, B. Koivisto
Dec 2, 2011
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0
Influential Citations
10
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Journal
Organometallics
Abstract
A series of bis-tridentate Ru(II) complexes consisting of trimethyl-4,4′,4″-tricarboxylate-2,2′:6′,2″-terpyridine (Me3tctpy) and derivatized 6-phenyl-2,2′-bipyridine (pbpy) ligands are reported. Each complex is attached to a terminal triphenylamine (TPA) substituent at the central ring of pbpy through a thiophene bridge to benefit light absorption, while the anionic ring of pbpy is functionalized with substituents to modulate the metal-based redox potential. The cyclometalation step was found to favor the isomer where the electron-donating groups (EDGs; i.e., −OEt, −SEt) are situated ortho to the organometallic bond rather than the sterically favored para position, while the para isomer is formed in exclusivity when electron-withdrawing groups (e.g., −CF3) are installed on the anionic ring. Moreover, the distribution of the isomeric products is affected by the identity of the chalcogen: ortho:para = 1:0 and 3:1 where EDG = −OEt and −SEt, respectively. Because our molecular scaffold rules out certain cyclo...