EXPERIMENTAL AND THEORETICAL-STUDIES OF THE LOW-LYING ELECTRONIC STATES OF THE SIMPLEST BENZYLIC AMIDE [2]CATENANE

The lowest electronically excited states of the simplest benzylic amid e [2]catenane (1) have been studied by a combination of experimental a nd theoretical techniques. Experimentally, steady-state and transient absorption spectra, emission spectra, and the optoacoustic response in solution have been recorded for the catenane and a model compound (N, N'-dibenzylisophthalic diamide (2)), as well as the electron energy l oss spectrum of the catenane deposited on the Au(111) surface. The the oretical picture builds on the results of semiempirical quantum chemic al calculations and shows that partial delocalisation of the electroni c states over the many chromophores of the catenanes can occur. (C) 19 98 Elsevier Science B.V. All rights reserved.