The CNDO/2 method was to study the adsorption behavior of H2, O2, and CO on pyrrole and model macromols. built up from pyrrole units. Different orientations of the adsorption of the adsorbed mol. relative to the heterocyclic hydrocarbon were considered. The intermol. distance was optimized with respect to the energy for each composite system. The dependence of the interaction energy on the intermol. distance and on the no. of pyrrole units was examined A series of useful rules in agreement with experimental findings were obtained.

Key words: OXYGEN, CARBON MONOXIDE, COMPLEX COMPOUNDS, CNDO APPROXIMATION, BONDING, ELECTRIC CHARGE, PYRROLE, BINDING ENERGY, INTERACTIONS, GEOMETRICAL ISOMERISM