1. Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan; Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; Neutron Science Laboratory, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba 305-0801, Japan; and ISIS, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK