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.