Lanthanide-Based Coordination Polymers for the Size-Selective Detection of Nitroaromatics

Lanthanide coordination polymers (LnCPs), [Eu(HL)(3)(CH3OH)(2)](n) (1) and [Tb(HL)(3)(CH3OH)(H2O)]center dot H2O (2) (H2L = 3-(picolinamido)benzoic acid)), have been synthesized and characterized. Single crystal analyses of both LnCPs display that HL ligands not only coordinate to Ln ions but also act as the bridge between them generating one-dimensional (ID) chains. Such ID chains further pack into three-dimensional (3D) architectures by the mediation.of H-bonding interactions. Both LnCPs offer strategically placed exposed Lewis basic sites, which potentially interact with the electron-deficient nitroaromatics, whereas H-bonded 3D architecture having hydrophobic channels allows their facile inclusion within the, network. A notable feature is the size-dependent sensing of nitroaromatics potentially governed by the packing of 1D chains into a 3D architecture. Both LnCPs act as the fluorescent sensor for quick, sensitive, and selective detection of nitrobenzene not only in solution but also in the vapor phase suggesting potential applications in the sensing devices for the detection of nitroaromatics.