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Inorg Chem

Title:		Highly Selective Chloromethanes Detection Based on Quartz Crystal Microbalance Gas Sensors with Ba-MOFs
Author(s):		Liu Y; Fan Y; Hou C; Du W; Zhang D; Liu Y; Xu J; Bai YL;
Address:		"NEST Lab, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, P.R. China. International Center for Quantum and Molecular Structures, College of Sciences, Shanghai University, Shanghai 200444, P.R. China"
Journal Title:		Inorg Chem
Year:		2021
Volume:		20211022
Issue:		21
Page Number:		16370 - 16377
DOI:		10.1021/acs.inorgchem.1c02185
ISSN/ISBN:		1520-510X (Electronic) 0020-1669 (Linking)
Abstract:		"Three new metal-organic frameworks (MOFs), (CH(3)NH(3))(3)[Ba(2)(TTHA)(NO(3))(H(2)O)(2)].2H(2)O (1), (CH(3)NH(3))(4)[Ba(3)(HTTHA)(2)(H(2)O)(7)].3H(2)O (2), and [Ba(7)(TTHA)(2)(NO(3))(2)(H(2)O)(10)].2H(2)O (3) (H(6)TTHA = 1,3,5-triazine-2,4,6-triamineh-exaacetic acid) have been synthesized and characterized. The sensing properties of 1-3 were explored with regard to volatile organic compounds (VOCs) by the quartz crystal microbalance (QCM) technique. The results indicated that 1 and 2 have a much higher selectivity and response to chloromethanes (CH(2)Cl(2), CHCl(3), and CCl(4)) compared with H(2)O, CH(3)OH, CH(3)CH(2)OH, CH(3)CN, (CH(3))(2)CO, C(6)H(6), C(6)H(5)CH(3), C(6)H(5)CH(2)CH(3), and C(6)H(5)Cl at room temperature. Furthermore, 1 and 2 sensing film also exhibits excellent reversibility and stability, and the response and recovery times are almost within 10 s. 3 displays a lower response and poor selectivity to the above VOCs. The significant difference may be caused by their different structural characteristics. The Ba(2+) ions are all decacoordinated in 1 and 2, while Ba(2+) ions have more open metal sites in 3. So, the high selectivity and response of 1 and 2 may be due to the exchange of coordination water molecules with chloromethanes and possible electrostatic effects between (CH(3)NH(3))(+) cations and chloromethanes containing more electronegative Cl atoms. DFT calculation results show that the bond energy of Ba-Cl and Ba-O is not much different, so chloromethanes at high concentrations may exchange coordination water to form weak Ba...Cl interactions and show higher response values. 3 has no obvious VOCs selectivity and higher response due to more open sites of Ba(2+) ions and smaller pore size. This work develops a fast and effective method to detect chloromethanes, providing a new opportunity for designing QCM gas sensors coated with different MOF materials"
Keywords:
Notes:		"PubMed-not-MEDLINELiu, Yanan Fan, Yu Hou, Chaoyi Du, Wei Zhang, Dan Liu, Yu Xu, Jiaqiang Bai, Yue-Ling eng 2021/10/23 Inorg Chem. 2021 Nov 1; 60(21):16370-16377. doi: 10.1021/acs.inorgchem.1c02185. Epub 2021 Oct 22"