Metal assisted cyclodimerization of doubly N-confused dipyrrins into planar aza-heptalenes

摘要: Metal salts cyclodimerize doubly N-confused dipyrrin into a nornorrole type macrocycle, with bipyrrolic unit at its center. It also represents an unusual aza-heptalene structure fused bicyclic seven membered rings. The rings can have one or two C–N bonds between the units in cyclodimer. 1H NMR spectrum of these molecules displays aromatic character, rather than antiaromatic behaviour expected nornorrole, and planar conformation solid state.