1. Department of Physical Chemistry and Department of Organic Technology, Institute of Chemical Technology, 166 28 Prague 6, Czech Republic, Ecole polytechnic fédérale de Lausanne, Ecublens, CH - 1015 Lausanne, Switzerland, and E.Hála Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, 165 02 Prague 6 - Suchdol, Czech Republic