Unexpected halide anion binding modes in meso-bis-ethynyl picket-calix[4]pyrroles: effects of meso-π (ethynyl) extensionElectronic supplementary information (ESI) available: Synthetic details, NMR and ITC titration profiles, and crystal structures. CCDC 1827178-1827181 and 1846661. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8cc04393k

meso -Ethynyl extended aryl-picket calix[4]pyrroles 2 and 3 are designed and synthesized by directly anchoring arylethynyl groups at diametrically opposed meso -positions. The critical roles of direct ethynyl linkers are manifested through the isolation of unexpected host-anion conformers of meso -arylethynyl calix[4]pyrroles and a significant enhancement in halide binding affinities. meso -Ethynyl extended aryl-picket calix[4]pyrroles 2 and 3 are designed and synthesized by directly anchoring arylethynyl groups at diametrically opposed meso -positions.