Naphthalene/anthracene chromophore-based W/S/Cu cluster-organic frameworks with adjustable Fe3+ sensing properties

Changing chromophore groups of organic ligands to regulate Fe3+ sensing properties of luminescent metalorganic frameworks (LMOFs) was firstly demonstrated. Naphthalene/anthracene chromophore-based organic ligands 1,4-bis(4-pyridine)naphthalene (L1), 9,10-bis(4-pyridine)anthracene (L2) and 9,10-bis(2-(pyridin-4-yl) vinyl)anthracene (L3) were deliberately selected to construct three new W/S/Cu cluster-based luminescent MOFs [(WS4Cu4)(1/2)(L1)(CN)](n) (1), [(WS4Cu4)(1/2)(L2)(3/)I-2 center dot DMF](n) (2) and [WS4Cu3(L3)(3/2)(SCN)](n) (3). Structurally, 1 possesses a 2-fold interpenetrated 3D diamondoid (dia) framework structure, which is constructed by pentanuclear clusters [WS4Cu4](2+), double CN- and naphthalene-containing Ll bridges; 2 is fabricated by pentanuclear clusters [WS4Cu4](2+) and single/double anthracene-containing L2 bridges to form a 5-fold interpenetrated 3D dia framework; 3 contains T-shaped clusters [WS4Cu3](+), single SCN- and single/double anthracene-containing L3 bridges, which results in a 2D [4,4] network. Moreover, 1 and 2 have good stability and luminescence performance. More importantly, luminescence measurements demonstrate that 1 shows better detection ability for Fe3+ relative to 2. Mechanism studies reveal that higher sensing efficiency is due to better competitive absorption.

Automated summary

The study demonstrates the regulation of Fe3+ sensing properties of luminescent metalorganic frameworks (LMOFs) by changing chromophore groups of organic ligands. Three new luminescent MOFs with different chromophore-based organic ligands were successfully constructed, among which MOFs 1 and 2 exhibit good stability and luminescence performance, with MOF 1 showing better detection ability for Fe3+ compared to MOF 2.