K Moriya1, K Shibuya1, Y Hattori1, S Tsuboi1, K Shiokawa1, S Kagabu1,2. 1. a Yuki Research Center, Nihon Bayer Agrochem Co. Ltd. , Yuki , Ibaraki 307 , Japan. 2. b Department of Chemistry, Faculty of Education , Gifu University , Gifu 501-11 , Japan.