错误:
Br2 %2B K4%5BFe%28CN%296%5D %3D KBr %2B K3%5BFe%28CN%296%5D
^
不需要的字符 ('%')Br2 %2B K4%5BFe%28CN%296%5D %3D KBr %2B K3%5BFe%28CN%296%5D
^
不需要的字符 ('%')