Homoleptic complexes of a porphyrinatozinc(ii)-2,2':6',2''-terpyridine ligand.
Three homoleptic complexes containing the metalloligand 7-(4-([2,2':6',2''-terpyridin]-4'-yl)phenyl)-5,10,15,20-tetraphenylporphyrinatozinc(ii), 1, have been prepared. [Zn(1)2][PF6]2, [Fe(1)2][PF6]2and [Ru(1)2][PF6]2were characterized by1H and13C NMR spectroscopy and mass spectrometry, and the electrochemical and photophysical properties of the complexes have been investigated. In solution, each complex undergoes two reversible porphyrin-centred oxidation processes, with an additional reversible metal-centred oxidation for [Fe(1)2][PF6]2and [Ru(1)2][PF6]2. Solution absorption spectra are dominated by the Soret and Q bands of the metalloligand 1. Spectroelectrochemical data for the complexes are presented. The results of a nanosecond transient absorption spectroscopic investigation of [Zn(1)2][PF6]2, [Fe(1)2][PF6]2and [Ru(1)2][PF6]2are presented. For [Zn(1)2][PF6]2, S1excitation leads to an efficient intersystem-crossing to the T1state, whilst for [Fe(1)2][PF6]2, excitation of the1MLCT transition is followed by fast deactivation to the3MC state followed by thermal decay to the ground state. Excitation of the1MLCT transition of [Ru(1)2][PF6]2results in an intersystem crossing to3MLCT; triplet-to-triplet energy transfer occurs giving the [Zn(TPP)] T1state which regenerates the ground state of the complex.
Department of Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland. catherine.housecroft@unibas.ch.
Angelo
A
Lanzilotto
Martin
M
Kuss-Petermann
Oliver S
OS
Wenger
Edwin C
EC
Constable
Catherine E
CE
Housecroft