A Conformationally Flexible Macrocyclic Dipyrrin Tetramer and Its Unsymmetrically Twisted Luminescent Zinc(II) Complex.

A macrocyclic dipyrrin tetramer containing flexible m-phenylene linkages and its tetranuclear zinc(II) complex were synthesized. The obtained complex has an unsymmetrical figure-of-eight structure because of the conformational flexibility of the macrocyclic framework. The first μ-hydroxo- and μ-acetato-bridged dinuclear zinc(II) dipyrrin complex structure is realized in the twisted macrocyclic complex. Furthermore, the complex exhibited an efficient emission in toluene and chloroform.