Ethylene-Bridged Hexadentate Bis(amidines) and Bis(amidinates) with Variable Binding Sites

Hexadentate bis­(amidines) form versatile networks of hydrogen bonds both in solid state and solution, as revealed by X-ray crystallography, IR, and NMR spectroscopy. Moreover, the corresponding bis­(amidinates) produce blue and green emissions in THF solution. Tethered tetradentate bis­(amidines) have emerged in coordination chemistry, enantioselective catalysis, as building blocks for polyfunctional heterocycles, and in photoluminescent materials. The next generation of flexible bis­(amidine)/bis­(amidinate) platforms with up to six N-donor sites has now been established.