[1] Tianjin Univ, Sch Sci, Dept Chem, Tianjin Key Lab Mol Optoelect Sci, Tianjin 300072, Peoples R China
[2] City Univ Hong Kong, Dept Chem, Hong Kong, Peoples R China
[3] Emory Univ, Dept Chem, 1515 Pierce Dr, Atlanta, GA 30322 USA
[4] Univ Cambridge, Cavendish Lab, Cambridge, England