A ferrocene functionalised macrocyclic receptor for cations and anions

The isolation and characterisation of a new macrocyclic hexaamine trans-6,1 3-bis(ferrocenylmethylamino)-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecan e (L-2) bearing two ferrocenyl groups appended to its exocyclic amines is r eported. The crystal structures of L-2 and its dihydrochloride salt L-2. 2H Cl . 2H(2)O have been determined. In the latter case cation-anion hydrogen bonding is observed in the solid state. Substrate binding by the electroact ive L-2 in MeCN-CH2Cl2 solution has been examined by cyclic voltammetry and reveals the receptor electrochemically to recognise benzoate and chloride anions. The macrocyclic N-donors may also bind transition metal cations suc h as Cu-II and Zn-II.