Concave reagents part 33: transition metal complexes of 1,10-phenanthroline bridged calix[6]arenes

Abstract

1,10-Phenanthroline bridged calix[6]arenes 1a and 1b have been synthesized and metal salt complexes with Cu⁺, Cu²⁺, Co²⁺, Ni²⁺ and Eu³⁺ have been isolated. In contrast to the concave 1,10-phenanthrolines 2, which only form 1:1 complexes with metal salts, 1 also forms 2:1 complexes with Cu²⁺, Co²⁺ and Ni²⁺. Only Cu⁺ forms 1:1 complexes exclusively.