STERIC CONDITIONS FOR DONOR-ACCEPTOR INTERACTIONS IN C-60 COMPLEXES WITH PLANAR ORGANIC DONORS

Charge transfer complexes of fullerene C-60 With planar donors of tetr athiafulvalene, dithiadiazafulvalene and pyranylidene family were inve stigated by IR- and W-VIS-NIR spectroscopy. The analysis of IR and X-r ay data shows that the charge transfer complexes of fullerene with the planar donors are involved in polarization interactions of van der Wa als type. Charge transfer is very weak in these compounds and is hinde red by unfavourable steric factors. As a result, the CT rate does not correlate with the ionization potential of the donor; the charge trans fer absorption bands are very weak too. (C) 1998 Elsevier Science B.V. All rights reserved.