Indole complexes

Lo and co-workers reported the synthesis, characterisation, photophysical and electrochemical properties of luminescent rhenium(I) diimine indole complexes [Re(N"N)(CO)3(py-indole)]+ (36) [75,76]. Upon visible-fight irradiation, the complexes exhibited 3MLCT (dTt(Re) —> Tt (N N)) emission in fluid solutions at 298 K and in low-temperature glass. When these com-... 

Luminescent ruthenium(II) polypyridine indole complexes such as [Ru (bpy)2(bpy-indole)]2+ (37) and their indole-free counterparts have been synthesised and characterised [77]. The ruthenium(II) indole complexes display typical MLCT (djt(Ru) tt (N N)) absorption bands, and intense and long-lived orange-red 3MLCT (djt(Ru) -> Ti (bpy-indolc)) luminescence upon visible-light irradiation in fluid solutions at 298 K and in alcohol glass at 77 K. In contrast to the rhenium(I) indole complexes, the indole moiety does not quench the emission of the ruthenium(II) polypyridine complexes because the excited complexes are not sufficiently oxidising to initiate electron-transfer reactions. Emission titrations show that the luminescence intensities of the ruthenium(II) indole complexes are only increased by ca. 1.38- to... 

V vs. SCE), reductive quenching of the excited complexes by the appended indole ( ,0[indole+,°] < +1.06 V vs. SCE) is favoured by > 0.2-0.4 eV. From this, together with results from transient absorption spectroscopic measurements, it is concluded that the emission quenching of the indole-containing complexes is a result of electron-transfer. The interactions of these rhenium(I) indole complexes with... 

EADIND. 9-Ethyyladenine indole complex (C7H9N5, C8H7N). Kaneda T, Ihnaka J (1976) Bull Chem Soc Jpn 49 1799... 

When the C-3 position is substituted (e.g., with Me), deprotonation is selective for C-7 even in the presence of a proton at C-2. At the same time, a large blocking group at the indole N (60) generates steric hindrance to deprotonation of both C-2 and C-7 selective lithiation at C-4 results [29, 45, 52, 57]. The N-(tri(isopropyl)-silyl)indole complex (60) can be deprotonated with 2 mol-eq. of n-BuLi at -78 °C for 3 h, and then trapped with a variety of electrophiles to give... 

The red-brown indole complexes [Pd2L2X4] (X = Cl or Br) have been synthesized... 

X 10" M n= ) and 5-hydroxyindole-3-acetic acid (Ka = 2.0x 10" M = 1). The rhenium(I) indole complexes can inhibit another indole-binding protein, tryptophanase. A standard assay, which is on the basis of the conversion of L-serine to pyruvate by the enzyme, has been carried out. Under the standard experimental conditions, at [L-serine] = 800 mM, free indole inhibit 53% of the enzyme activity, while the indole-containing complexes... 

Both the carbene and the indole complexes are susceptible to protonation, the former... 

---