It is demonstrated that the pyridyl ligand in complex 1 dissociates easily to become [(4,4-(COOEt)_2-bpy)Re(CO)_3]~+ because of the relative crowded spacial configuration with the increase of CID fragmention.

• 结果表明；由于络合物1的空间结构相对拥挤；随着CID电压升高；其中的吡啶配体容易发生离解并形成稳定的联吡啶三羰基配位离子[(4；4-(′COOEt)2-bpy)Re(CO)3]+.