The molecular structure of copper- and nickel-phthalocyanine as determined by gas-phase electron diffraction and ab initio/DFT computations

The structure of two metal phthalocyanines (MPcs) where M = Ni and Cu, have been determined by gas-phase electron diffraction for the first time. Structural analysis is assisted by ab initio/DFT calculations, carried out in the present work for NiPc and taken from the literature for CuPc. The focus of these studies is the position of the metal ion relative to the 16-membered C8N8 ring. Both molecules were found to be planar. Slight non-planarity found in the previous study is now removed by a new procedure of structural analysis; this is in accordance with the results of the X-ray studies and ab initio/DFT calculations for both compounds. From comparisons presented here we san conclude that there is a close structural similarity of MPcs in the gas phase and in the crystal. (C) 2000 Elsevier Science B.V. All rights reserved.