Metal π Complexes of Carbazole Derivatives for Optoelectronics:  Synthesis, Structures, and UV−Visible Absorption Spectra of (3-Amino-9-ethylcarbazole)chromium Tricarbonyl Complexes

Chromium tricarbonyl complexes η6-bonded to 3-amino-9-ethylcarbazole at either the NH2-substituted aryl ring (1) or the unsubstituted aryl ring (2) have been synthesized and their UV−visible absorption spectra determined. In comparison to 2, 1 causes a subtle blue shift in the metal-to-ligand charge-transfer band along with spectral shape changes due to electron transfer from the NH2 substituent to the Cr(CO)3 center.