7th International Chemistry Symposium
SIQ 2019
Alkylamines and arylamines, which have been extensively used in many industrial processes, have been found as dangerous residues in air, soil, surface water and groundwater at risk concentrations. Therefore, they represent a prominent threat to human health and environment. Hence, the detection of volatile amines species is essential in terms of environmental safety. In this sense, luminescent chemical sensors based on Metal-Organic Frameworks (MOFs) have become a promising alternative for the sensing and monitoring of amines in situ. In this study, we investigated the Turn-off luminescence mechanism of the MOF labelled UiO-67-dmbpy, which belongs to a family of robust MOFs based on octahedral [Zr6O4(OH)4dmbpy)12]; dmbpy: N,N’-dimethyl-2,2’-bipyridinium, reported by En-Qing et al. in 2017 as a selective chemical sensor to alkylamines. A theoretical study by means of the DFT (Density Functional Theory) and the TD-DFT (Time-dependent DFT) was performed. Because of a big size of the MOF, a fragmentation scheme was applied with the purpose of optimizing time and computational resources. Thus, the structure was reduced from a secondary building unit (SBU) [Zr6O4(OH)4(dmbpy)12], to a geometry containing eleven organic linkers truncated to capping formate groups [Zr6O4(OH)4(HCOO)11(dmbpy)]. Besides, an analysis of the host (MOF)–guest(alkylamines) interactions via the Morokuma-Ziegler energy decomposition scheme and the NOCV (Natural Orbitals for Chemical Valence) were carried out. The structural model proposed in this work successfully reproduces the luminescent properties of the system. Results indicate that the emission at 405 nm is linkers-centered (experimental value 411 nm). This band was assigned to the ligand centered (π-π*) transition. Acknowledgments: Acknowledgements: The authors thank to Ph.D. Program in Molecular Physical Chemistry from Universidad Andrés Bello. DGA-UNAB, FONDECYT 1180017, FONDECYT 1180565. References: [1] JANG, J.-K; et al. Ind. Health, 54 (2), 2016,101–115. [2] Liang-Yu Chang; et al. ACS Sens. 2 (4),2017, 531–539. [3] En-Qing Gao; et al.; Chem. Commun, 53 (10), 2017, 1747-1750 . [4] Poater, J.; Gimferrer, M.; Inorg. Chem. 57 (12) 2018, 57 (12), 6981–6990. [5] Baerends, E. J; et al. Amsterdam Density Functional; SCM, Theoretical Chemistry, Vrije Universiteit, Amsterdam, The Nether- lands, 2012; http://www.scm.com.
Alkylamines and arylamines, which have been extensively used in many industrial processes, have been found as dangerous residues in air, soil, surface water and groundwater at risk concentrations. Therefore, they represent a prominent threat to human health and environment. Hence, the detection of volatile amines species is essential in terms of environmental safety. In this sense, luminescent chemical sensors based on Metal-Organic Frameworks (MOFs) have become a promising alternative for the sensing and monitoring of amines in situ. In this study, we investigated the Turn-off luminescence mechanism of the MOF labelled UiO-67-dmbpy, which belongs to a family of robust MOFs based on octahedral [Zr6O4(OH)4dmbpy)12]; dmbpy: N,N’-dimethyl-2,2’-bipyridinium, reported by En-Qing et al. in 2017 as a selective chemical sensor to alkylamines. A theoretical study by means of the DFT (Density Functional Theory) and the TD-DFT (Time-dependent DFT) was performed. Because of a big size of the MOF, a fragmentation scheme was applied with the purpose of optimizing time and computational resources. Thus, the structure was reduced from a secondary building unit (SBU) [Zr6O4(OH)4(dmbpy)12], to a geometry containing eleven organic linkers truncated to capping formate groups [Zr6O4(OH)4(HCOO)11(dmbpy)]. Besides, an analysis of the host (MOF)–guest(alkylamines) interactions via the Morokuma-Ziegler energy decomposition scheme and the NOCV (Natural Orbitals for Chemical Valence) were carried out. The structural model proposed in this work successfully reproduces the luminescent properties of the system. Results indicate that the emission at 405 nm is linkers-centered (experimental value 411 nm). This band was assigned to the ligand centered (π-π*) transition. Acknowledgments: Acknowledgements: The authors thank to Ph.D. Program in Molecular Physical Chemistry from Universidad Andrés Bello. DGA-UNAB, FONDECYT 1180017, FONDECYT 1180565. References: [1] JANG, J.-K; et al. Ind. Health, 54 (2), 2016,101–115. [2] Liang-Yu Chang; et al. ACS Sens. 2 (4),2017, 531–539. [3] En-Qing Gao; et al.; Chem. Commun, 53 (10), 2017, 1747-1750 . [4] Poater, J.; Gimferrer, M.; Inorg. Chem. 57 (12) 2018, 57 (12), 6981–6990. [5] Baerends, E. J; et al. Amsterdam Density Functional; SCM, Theoretical Chemistry, Vrije Universiteit, Amsterdam, The Nether- lands, 2012; http://www.scm.com.
About The Speaker
Yoan Hidalgo Rosa
