Studies of bound form on rare earths in a natural plant fern DicranopterisDichotoma by spectroscopy

Distribution of RE and structure characterization of RE-chlorophyll in a na tural plant fern Dicranopteris Dichotoma in rare earth mining area were stu died by spectrocopy. The results showed that the cerium content in total ra re earths (79. 43%, 66. 71%) was the highest in leaf and chlorophyll, respe ctively. The fluorescence emission peaks of photosystem I in D. Dichotoma w ere more violet shift by 15 similar to 25 nm. than that of common plant. Th e fluorescence intensity of photosystem II was as 6. 79 time as that of pho tosystem I. It showed that RES can increase the activities of photosystem I I. The spectral characterization of UV-Vis and FTIR on chlorophyll a in D. dichotoma are similar as standard chlorophyll a and couldn't suggest coordi nation information on REs for its very low contents of RE-chlorophyll in D. Dichotoma. Extended X-ray absorption fine structure (EXAFS) spectral analy sis revealed that cerium coordinated two porphyrin rings with coordination number of eight, the bond length of Ce-N was 0. 252 nm, respectively; Ce-ch lorophyll-a may have bilayer structure in D. Dichotoma.