title: Polyfunctional Lewis acids: intriguing solid-state structure and selective detection and discrimination of nitroaromatic explosives.
abstract: Synthesis and crystal structures of three porphyrin-based polyfunctional Lewis acids 1-3 are reported. Intermolecular HgCl⋅⋅⋅HgCl (linear and μ-type) interactions in the solid state of the peripherally ArHgCl-decorated compound 3 lead to a fascinating 3D supramolecular architecture. Compound 3 shows a selective fluorescence quenching response to picric acid and discriminates other nitroaromatic-based explosives. For the first time, an electron-deficient polyfunctional Lewis acid is shown to be useful for the selective detection and discrimination of nitroaromatic explosives. The Stern-Volmer quenching constant and detection limits of compound 3 for picric acid are the best among the reported small-molecular receptors for nitroaromatic explosives. The electronic structure, Lewis acidity, and selective sensing characteristics of 3 are well corroborated by DFT calculations.
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science (IISc), Bangalore 560012 (India), Fax: (+91) 80-23601552.
authors.forename: Chinna Ayya
authors.initials: CA
authors.lastname: Swamy P
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science (IISc), Bangalore 560012 (India), Fax: (+91) 80-23601552. thilagar@ipc.iisc.ernet.in.
authors.forename: Pakkirisamy
authors.initials: P
authors.lastname: Thilagar
keywords: Lewis acids; mercury; porphyrinoids; sensors; supramolecular chemistry