Molecular complexes between π-excedent heterocycles (indoles and carbazole) and π-deficient polynitrobenzenes

Five charge-transfer complexes 1-5 derived from indoles (including a carbazole) and halogenopolynitrobenzenes (CIDNB, FDNB, CITNB) as well as their individual components have been studied in the solid state by C-13 CPMAS NMR. The stacking effects on the C-13 chemical shifts have been rationalized by means of M05-2X functional and GIAO/B3LYP/6-311++G(d,p) calculations. The results, although only semiquantitative, are very promising for studying such structures. Copyright (C) 2009 John Wiley & Sons, Ltd.