Intramolecular photo-substitution in the inclusion compound of mono[6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]–β-cyclodextrin with cyclopentadienyl manganese tricarbonyl in DMF solution

A novel β-CD derivative, mono[6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]–β-CD 1, and its inclusion compound 2 with CpMn^I(CO)₃ have been prepared and characterized by spectroscopic methods. The inclusion complexation significantly stabilized both the host and guest. Upon irradiation of inclusion compound 2 in DMF solution, an interesting intramolecular photo-substitution resulting in the formation of a self-stabilized compound mono[6-deoxy-6-(2-butenedinitrile-2,3-dimercapto sodium salt)]–β-CD–Mn^II(DMF)₂Cp 5 was observed. Based upon a double-recognition between the host and the organometallic guest, compound 5 became very stable in DMF solution.