Substitution of Ru(ii)-based chromophores with cheaper Cr(iii)-based complexes in optically active metallo-supramolecular architectures is limited by the lack of synthetic strategies leading to heteroleptic Cr(iii)-polypyridyl complexes with long excited-state lifetimes. Herein, we report on a versatile method yielding heteroleptic bis(terdentate) Cr(iii) complexes with room temperature millisecond range excited-state lifetimes, tuneable electronic and photophysical properties and easy anchoring possibilities.