In2Q2: A New Entry of 16-Membered Tetraazamacrocycle Concatenating Indole and Quinoline Units

Chemistry. 2024 May 2;30(25):e202304176. doi: 10.1002/chem.202304176. Epub 2024 Mar 12.

Abstract

A new family of 16-membered macrocycles comprising two indole (In) and two quinoline (Q) units, coined In2Q2, was synthesized. Each unit is diagonally located and concatenated in a head-to-tail fashion, furnishing a non-flat saddle-shaped architecture with C2 symmetry. The synthetic protocol utilizing macrocyclic diamide as a pivotal precursor allowed us to access a series of In2Q2 derivatives bearing various substituents on the periphery. The In2Q2 derivatives and their Zn2+ complexes were emissive in both solution phase and solid state. While the entire architecture of In2Q2 is similar to that of quinoline tetramer TEtraQuinoline, a couple of contrasting physicochemical properties were revealed.

Keywords: indole; macrocycle; metal complex; quinoline; tetradentate.