An NMR investigation on the adducted hydrogen in weak ferromagnetic rhombohedral C-60 polymers

作者:Yu Yao; Wu Jianbao; Gu Min*; Zhang Weiyi; Cui Guanglei; Xu Xibin; Feng Duan; Tang Tong Bor
来源:Chemical Physics Letters, 2009, 482(1-3): 66-71.
DOI:10.1016/j.cplett.2009.09.070

摘要

The fact that a magnetic hysteresis loop is observed only in polymerized C-60 and is absent in both pristine and depolymerized C-60 establishes a close link between the weak ferromagnetism and the underlying structure. Furthermore, the correlation between the weak ferromagnetism and hydrogen presence has been explored by H-1 NMR and H-1-C-13 cross-polarization NMR, whereby strong bonding between the H adducts and C-60 has been verified. The adducted hydrogens most likely form bonds with the carbon atoms of inter-C-60 four-membered rings. This conclusion is further supported by the formation energy of adducted H and the exchange energy among adducted H obtained from first-principle calculations on Rh-C-60.