A new class of anionic metallohelicates based on salicylic and terephthalic acid units, accessible in solution and by mechanochemistry.

We present a new class of anionic metallohelicates based on an abundant, industrially relevant salicylic acid derivative, leading to discrete double and triple-stranded architectures based on divalent and trivalent metals (Cu2+, Fe3+, respectively). The ability to assemble the metallohelicates in a solvent-free environment presents the opportunity to develop an inexpensive and environmentally-friendly design of helicate materials.