MOLECULAR COCRYSTALS OF CARBOXYLIC-ACIDS - XXXIII - THE CRYSTAL-STRUCTURE OF THE 1 1 ADDUCT OF INDOLE-2-CARBOXYLIC ACID WITH 5-NITROQUINOLINE/

The molecular adducts of indole-3-acetic acid (iaa) and indole-2-carbo xylic acid (ica) with 5-nitroquinoline (nq), [(iaa)(nq)(2)] (1) and [( ica)(nq)] (2), have been prepared and characterized by X-ray diffracti on and spectroscopic methods. Both examples involve charge transfer as well as a network of hydrogen-bonding interactions. Thin films of com pound (2), and other similar adduct complexes of ica, can be prepared by thermal evaporation techniques and in this form exhibit a weak seco nd-order non-linear optical signal. However, these films display poor optical quality and, without improvement, are not suitable for any pot ential non-linear optical applications.