[1] Univ Erlangen Nurnberg, Inst Phys Chem, D-91058 Erlangen, Germany
[2] Oklahoma State Univ, Dept Chem, Stillwater, OK 74078 USA
[3] Univ Bologna, Dipartimento Chim G Ciamician, I-40126 Bologna, Italy
[4] Univ Trieste, Dipartimento Sci Farmaceut, I-34127 Trieste, Italy