Abstract
The synthesis, characterization, and photophysical properties of the N6–N5C bichromophoric [(bpy)2Ru(I)Ru(ttpy)][PF6]3(bpy is 2,2′-bipyridine and ttpy is 4′-p-tolyl-2,2′:6′,2′-terpyridine) and [(bpy)2Ru(II)Ru(ttpy)][PF6]3(I and II are bpy-dipyridylbenzene ditopic ligands bridged by an ethynyl and phenyl unit, respectively) complexes are reported together with the model mononuclear complexes [(bpy)2Ru(I)][PF6]2, [(bpy)2Ru(II)][PF6]2, [Ru(VI)(ttpy)][PF6] (VI is 3,5-di(2-pyridyl)-biphenyl) and [Ru(dpb)(ttpy)][PF6] (Hdpb is 1,3-di(2-pyridyl)-benzene). The electrochemical data show that there is little ground state electronic communication between the metal centers in the bimetallic complexes. Selective excitation of the N5C unit in the bichromophoric systems leads to luminescence typical for a bis-tridentate cyclometallated ruthenium complex and is similar to the [Ru(VI)(ttpy)][PF6] model complex. In contrast, the luminescence from the tris-bidentate N6unit is efficiently quenched by energy transfer to the N5C unit. The energy transfer rate has been determined by femtosecond pump–probe measurements to 0.7 ps in the ethynyl-linked [(bpy)2Ru(I)Ru(ttpy)][PF6]3and to 1.5 ps in the phenyl-linked [(bpy)2Ru(II)Ru(ttpy)][PF6]3(in acetonitrilesolution at 298 K), and is inferred to occur via a Dexter mechanism.
| Original language | English |
|---|---|
| Pages (from-to) | 1434-1443 |
| Number of pages | 10 |
| Journal | Journal of the Chemical Society. Dalton Transactions |
| Volume | 6 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Nov 29 2005 |
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Rapid energy transfer in bichromophoric tris-bipyridyl/cyclometallated ruthenium(ii) complexes. / Ott, Sascha; Borgström, Magnus; Hammarström, Leif; Johansson, Olof.
In: Journal of the Chemical Society. Dalton Transactions, Vol. 6, No. 2, 29.11.2005, p. 1434-1443.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Rapid energy transfer in bichromophoric tris-bipyridyl/cyclometallated ruthenium(ii) complexes
AU - Ott, Sascha
AU - Borgström, Magnus
AU - Hammarström, Leif
AU - Johansson, Olof
PY - 2005/11/29
Y1 - 2005/11/29
N2 - The synthesis, characterization, and photophysical properties of the N6–N5C bichromophoric [(bpy)2Ru(I)Ru(ttpy)][PF6]3(bpy is 2,2′-bipyridine and ttpy is 4′-p-tolyl-2,2′:6′,2′-terpyridine) and [(bpy)2Ru(II)Ru(ttpy)][PF6]3(I and II are bpy-dipyridylbenzene ditopic ligands bridged by an ethynyl and phenyl unit, respectively) complexes are reported together with the model mononuclear complexes [(bpy)2Ru(I)][PF6]2, [(bpy)2Ru(II)][PF6]2, [Ru(VI)(ttpy)][PF6] (VI is 3,5-di(2-pyridyl)-biphenyl) and [Ru(dpb)(ttpy)][PF6] (Hdpb is 1,3-di(2-pyridyl)-benzene). The electrochemical data show that there is little ground state electronic communication between the metal centers in the bimetallic complexes. Selective excitation of the N5C unit in the bichromophoric systems leads to luminescence typical for a bis-tridentate cyclometallated ruthenium complex and is similar to the [Ru(VI)(ttpy)][PF6] model complex. In contrast, the luminescence from the tris-bidentate N6unit is efficiently quenched by energy transfer to the N5C unit. The energy transfer rate has been determined by femtosecond pump–probe measurements to 0.7 ps in the ethynyl-linked [(bpy)2Ru(I)Ru(ttpy)][PF6]3and to 1.5 ps in the phenyl-linked [(bpy)2Ru(II)Ru(ttpy)][PF6]3(in acetonitrilesolution at 298 K), and is inferred to occur via a Dexter mechanism.
AB - The synthesis, characterization, and photophysical properties of the N6–N5C bichromophoric [(bpy)2Ru(I)Ru(ttpy)][PF6]3(bpy is 2,2′-bipyridine and ttpy is 4′-p-tolyl-2,2′:6′,2′-terpyridine) and [(bpy)2Ru(II)Ru(ttpy)][PF6]3(I and II are bpy-dipyridylbenzene ditopic ligands bridged by an ethynyl and phenyl unit, respectively) complexes are reported together with the model mononuclear complexes [(bpy)2Ru(I)][PF6]2, [(bpy)2Ru(II)][PF6]2, [Ru(VI)(ttpy)][PF6] (VI is 3,5-di(2-pyridyl)-biphenyl) and [Ru(dpb)(ttpy)][PF6] (Hdpb is 1,3-di(2-pyridyl)-benzene). The electrochemical data show that there is little ground state electronic communication between the metal centers in the bimetallic complexes. Selective excitation of the N5C unit in the bichromophoric systems leads to luminescence typical for a bis-tridentate cyclometallated ruthenium complex and is similar to the [Ru(VI)(ttpy)][PF6] model complex. In contrast, the luminescence from the tris-bidentate N6unit is efficiently quenched by energy transfer to the N5C unit. The energy transfer rate has been determined by femtosecond pump–probe measurements to 0.7 ps in the ethynyl-linked [(bpy)2Ru(I)Ru(ttpy)][PF6]3and to 1.5 ps in the phenyl-linked [(bpy)2Ru(II)Ru(ttpy)][PF6]3(in acetonitrilesolution at 298 K), and is inferred to occur via a Dexter mechanism.
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U2 - 10.1039/b508655h
DO - 10.1039/b508655h
M3 - Article
VL - 6
SP - 1434
EP - 1443
JO - Dalton Transactions
JF - Dalton Transactions
SN - 1477-9226
IS - 2
ER -