[1] Univ Lille 1, Ctr Etud & Rech Lasers & Applicat, Lab Phys Lasers Atom & Mol, F-59655 Villeneuve Dascq, France
[2] Univ Marne la Vallee, Chim Theor Lab, F-77454 Champs Sur Marne, France
[3] Univ Birmingham, Sch Chem, Birmingham B15 2TT, W Midlands, England