Finding a receptor design for selective recognition of perrhenate and pertechnetate: hydrogen vs. halogen bondingElectronic supplementary information (ESI) available: Synthetic details, NMRtitrations. CCDC 1828355. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8cc02048e

Receptors bearing hydrogen and halogen bond donors for recognition of perrhenate and pertechnetate were designed and studied. Acyclic hosts with N-H and C-H binding sites showed the best selectivity for TcO 4 − and ReO 4 − over spherical and more basic tetrahedral anions. Receptors bearing hydrogen and halogen bond donor sites for recognition of perrhenate and pertechnetate were designed and studied.