Journal article

Publication year: 2015

Pages: 4070-4079

Journal: Dalton Transactions

Volume number: 44

Issue number: 9

ISSN: 1477-9226

DOI Link: https://doi.org/10.1039/c4dt03578j

Publisher: Royal Society of Chemistry

Abstract: 
The blue emitting luminescent MOF 3∞[Ce(Im)3ImH]·ImH forms a 3D-framework with Kagomé net topology. The framework exhibits an intense blue luminescence which can be retained upon activation of the MOF with the formula 3∞[Ce(Im)3ImH]. The luminescence is metal-based due to parity-allowed 5d–4f-transitions. Time-dependent investigations of the interaction with liquid and gas analytes show that the MOF – by utilising 5d–4f-transitions of Ce3+ – can be used as a high-speed “turn-off” detector for water and oxygen in dry air. Other protic or polar solvents, like methanol, acetone or pyridine, which also show a “turn-off”-effect can be distinguished from water-detection either on a time scale (ranging up to 250 000 : 1) or a shift of the chromaticity, the latter being pronounced for MeOH. The fast time-dependent decrease of the luminescence intensity for water arises from an extremely fast hydrolysis and is irreversible. Polar aprotic molecules like dichloromethane and acetonitrile can also result in a “turn-on”-effect of the luminescence intensity due to their behaviour as additional sensitizers for Ce3+-emission. We conclude that the cerium-MOF can be utilised in gas and liquid sensing applications as a detector material for water and oxygen in dry air. The luminescence is intense with good quantum yield between 55% (as-synthesised) and 36% (activated). This implies that only milligram amounts of the material are needed to detect the analyte species and is especially useful, as the MOF can be directly used as-synthesised for water detection in applications for which an irreversible signal change is desired, e.g. preventing a signal change upon unwanted re-drying.

Harvard Citation style: Meyer, L., Schönfeld, F., Zurawski, A., Mai, M., Feldmann, C. and Müller-Buschbaum, K. (2015) A blue luminescent MOF as a rapid turn-off/turn-on detector for H2O, O2 and CH2Cl2, MeCN: 3∞[Ce(Im)3ImH]·ImH, Dalton Transactions, 44(9), pp. 4070-4079. https://doi.org/10.1039/c4dt03578j

APA Citation style: Meyer, L., Schönfeld, F., Zurawski, A., Mai, M., Feldmann, C., & Müller-Buschbaum, K. (2015). A blue luminescent MOF as a rapid turn-off/turn-on detector for H2O, O2 and CH2Cl2, MeCN: 3∞[Ce(Im)3ImH]·ImH. Dalton Transactions. 44(9), 4070-4079. https://doi.org/10.1039/c4dt03578j