1. Department of Surface Chemistry, National Institute of Materials and Chemical Research, 1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan, Applied Chemistry Department, József Attila University, Rerrich B. tér 1, H-6720 Szeged, Hungary, and Department of Organic Chemistry, József Attila University, Dóm tér 8, H-6720 Szeged, Hungary