Adsorption and Separation of Reactive Aromatic Isomers and Generation and Stabilization of Their Radicals within Cadmium(II)−Triazole Metal−Organic Confined Space in a Single-Crystal-to-Single-Crystal Fashion

摘要

Abstract: A series of reactive group functionalized aromatics, namely 2-furaldehyde, 3-furaldehyde,n2-thenaldehyde, 3-thenaldehyde, o-toluidine, m-toluidine, p-toluidine, and aniline, can be absorbed by anCdL2 (1;L 4-amino-3,5-bis(4-pyridyl-3-phenyl)-1,2,4-triazole) porous framework in both vapor and liquidnphases to generate new Gn⊂CdL2 (n 1, 2) host guest complexes. In addition, the CdL2 framework cannbe a shield to protect the active functional group (sCHO and sNH2) substituted guests from reaction withnthe outside medium containing their reaction partners. That is, aldehyde-substituted guests within the CdL2nhost become “stable” in the aniline phase and vice versa. Moreover, 1 displays a very strict selectivity fornthese reactive group substituted aromatic isomers and can completely separate these guest isomers undernmild conditions (i.e., 2-furaldehyde vs 3-furaldehyde, 2-thenaldehyde vs 3-thenaldehyde, and o-toluidinenvs m-toluidine vs p-toluidine). All adsorptions and separations are directly performed on the single crystalsnof 1. More interestingly, these reactive group substituted aromatics readily transform to the correspondingnradicals within the CdL2 host upon ambient light or UV light (355 nm) irradiation. Furthermore, the generatednorganic radicals are alive for 1 month within the interior cavity in air under ambient conditions. Simplenorganic radicals are highly reactive short-lived species, and they cannot be generally isolated and conservednunder ambient conditions. Thus, the CdL2 host herein could be considered as a radical generator andnstorage vessel.