TY - JOUR
T1 - Luminescent probes for indole-binding proteins derived from ruthenium(II) polypyridine complexes
AU - Lo, Kenneth Kam-Wing
AU - Lee, Terence Kwok-Ming
AU - Zhang, Kenneth Yin
PY - 2006/4/10
Y1 - 2006/4/10
N2 - We report here the synthesis, characterisation, electrochemical, photophysical and protein-binding properties of four luminescent ruthenium(II) polypyridine indole complexes [Ru(bpy)2(L1)](PF6) 2 (1), [Ru(bpy)2(L2)](PF6)2 (2), [Ru(L1)3](PF6)2 (1a), and [Ru(L2) 3](PF6)2 (2a) (bpy = 2,2′-bipyridine; L1 = 4-(N-(2-indol-3-ylethyl)amido)-4′-methyl-2,2′-bipyridine; L2 = 4-(N-(6-N-(2-indol-3-ylethyl)hexanamidyl)amido)-4′-methyl-2, 2′-bipyridine). Their indole-free counterparts, [Ru(bpy) 2(L3)](PF6)2 (3) and [Ru(L3) 3](PF6)2 (3a) (L3 = 4-(N-(ethyl)amido)- 4′-methyl-2,2′-bipyridine), have also been synthesised for comparison purposes. Cyclic voltammetric studies revealed ruthenium-based oxidation at ca. +1.3 V versus SCE and diimine-based reductions at ca. -1.20 to -2.28 V. The indole moieties of complexes 1, 2, 1a and 2a displayed an irreversible wave at ca. +1.1 V versus SCE. All the ruthenium(II) complexes exhibited intense and long-lived orange-red triplet metal-to-ligand charge-transfer 3MLCT (dπ(Ru) → π*(L1-L3)) luminescence upon visible-light irradiation in fluid solutions at 298 K and in alcohol glass at 77 K. The binding of the indole-containing complexes to bovine serum album (BSA) has been studied by quenching experiments and emission titrations. © 2005 Elsevier B.V. All rights reserved.
AB - We report here the synthesis, characterisation, electrochemical, photophysical and protein-binding properties of four luminescent ruthenium(II) polypyridine indole complexes [Ru(bpy)2(L1)](PF6) 2 (1), [Ru(bpy)2(L2)](PF6)2 (2), [Ru(L1)3](PF6)2 (1a), and [Ru(L2) 3](PF6)2 (2a) (bpy = 2,2′-bipyridine; L1 = 4-(N-(2-indol-3-ylethyl)amido)-4′-methyl-2,2′-bipyridine; L2 = 4-(N-(6-N-(2-indol-3-ylethyl)hexanamidyl)amido)-4′-methyl-2, 2′-bipyridine). Their indole-free counterparts, [Ru(bpy) 2(L3)](PF6)2 (3) and [Ru(L3) 3](PF6)2 (3a) (L3 = 4-(N-(ethyl)amido)- 4′-methyl-2,2′-bipyridine), have also been synthesised for comparison purposes. Cyclic voltammetric studies revealed ruthenium-based oxidation at ca. +1.3 V versus SCE and diimine-based reductions at ca. -1.20 to -2.28 V. The indole moieties of complexes 1, 2, 1a and 2a displayed an irreversible wave at ca. +1.1 V versus SCE. All the ruthenium(II) complexes exhibited intense and long-lived orange-red triplet metal-to-ligand charge-transfer 3MLCT (dπ(Ru) → π*(L1-L3)) luminescence upon visible-light irradiation in fluid solutions at 298 K and in alcohol glass at 77 K. The binding of the indole-containing complexes to bovine serum album (BSA) has been studied by quenching experiments and emission titrations. © 2005 Elsevier B.V. All rights reserved.
KW - Bovine serum albumin
KW - Emission quenching
KW - Indole
KW - Luminescence
KW - Ruthenium(II) complexes
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U2 - 10.1016/j.ica.2005.07.027
DO - 10.1016/j.ica.2005.07.027
M3 - RGC 21 - Publication in refereed journal
SN - 0020-1693
VL - 359
SP - 1845
EP - 1854
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
IS - 6
ER -