a
Institute of Technical and Macromolecular Chemistry, RWTH Aachen University and DWI an der RWTH Aachen e.V., Forckenbeckstr. 50, 52056 Aachen, Germany
E-mail: keul@dwi.rwth-aachen.de
;
Fax: +49 241-8023301
;
Tel: +49 241-8026438
b
Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany