The effect of substituents on the surface modification of anatase nanoparticles with catecholate-type ligands: a combined DFT and experimental study
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Savić, Tatjana D.Čomor, Mirjana
Nedeljković, Jovan
Veljkovic, Dusan Z.
Zarić, Snežana D.
Rakić, Vesna M.
Janković, Ivana A.
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The surface modification of nanocrystalline TiO2 particles (45 angstrom) with catecholate-type ligands having different electron donating/electron withdrawing substituent groups, specifically 3-methylcatechol, 4-methylcatechol, 3-methoxycatechol, 3,4-dihydroxybenzaldehyde and 4-nitrocatechol, was found to alter the optical properties of nanoparticles in a similar way to catechol. The formation of the inner-sphere charge-transfer (CT) complexes results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites and a reduction of the effective band gap, being slightly less pronounced in the case of electron withdrawing substituents. The investigated ligands have the optimal geometry for binding to surface Ti atoms, resulting in ring coordination complexes of the catecholate type (binuclear bidentate binding-bridging) thus restoring six-coordinated octahedral geometry of surface Ti atoms. From the absorption measurements (Benesi-Hildebrand plot), the stability ...constants in methanol/water = 90/10 solutions at pH 2 in the order of 10(3) M-1 have been determined. The binding structures were investigated by using FTIR spectroscopy. Thermal stability of CT-complexes was investigated by using TG/DSC/MS analysis. Quantum chemical calculations on model systems using density functional theory (DFT) were performed to obtain the vibrational frequencies of charge transfer complexes, and the calculated values were compared with the experimental data.
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Physical Chemistry Chemical Physics, 2014, 16, 38, 20796-20805Funding / projects:
- Materials of Reduced Dimensions for Efficient Light Harvesting and Energy conversion (RS-MESTD-Integrated and Interdisciplinary Research (IIR or III)-45020)
- Size-, shape- and structure- dependent properties of nanoparticles and nanocomposites (RS-MESTD-Basic Research (BR or ON)-172056)
DOI: 10.1039/c4cp02197e
ISSN: 1463-9076; 1463-9084
PubMed: 25166456
WoS: 000342072300062
Scopus: 2-s2.0-84907500581
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VinčaTY - JOUR AU - Savić, Tatjana D. AU - Čomor, Mirjana AU - Nedeljković, Jovan AU - Veljkovic, Dusan Z. AU - Zarić, Snežana D. AU - Rakić, Vesna M. AU - Janković, Ivana A. PY - 2014 UR - https://vinar.vin.bg.ac.rs/handle/123456789/125 AB - The surface modification of nanocrystalline TiO2 particles (45 angstrom) with catecholate-type ligands having different electron donating/electron withdrawing substituent groups, specifically 3-methylcatechol, 4-methylcatechol, 3-methoxycatechol, 3,4-dihydroxybenzaldehyde and 4-nitrocatechol, was found to alter the optical properties of nanoparticles in a similar way to catechol. The formation of the inner-sphere charge-transfer (CT) complexes results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites and a reduction of the effective band gap, being slightly less pronounced in the case of electron withdrawing substituents. The investigated ligands have the optimal geometry for binding to surface Ti atoms, resulting in ring coordination complexes of the catecholate type (binuclear bidentate binding-bridging) thus restoring six-coordinated octahedral geometry of surface Ti atoms. From the absorption measurements (Benesi-Hildebrand plot), the stability constants in methanol/water = 90/10 solutions at pH 2 in the order of 10(3) M-1 have been determined. The binding structures were investigated by using FTIR spectroscopy. Thermal stability of CT-complexes was investigated by using TG/DSC/MS analysis. Quantum chemical calculations on model systems using density functional theory (DFT) were performed to obtain the vibrational frequencies of charge transfer complexes, and the calculated values were compared with the experimental data. T2 - Physical Chemistry Chemical Physics T1 - The effect of substituents on the surface modification of anatase nanoparticles with catecholate-type ligands: a combined DFT and experimental study VL - 16 IS - 38 SP - 20796 EP - 20805 DO - 10.1039/c4cp02197e ER -
@article{ author = "Savić, Tatjana D. and Čomor, Mirjana and Nedeljković, Jovan and Veljkovic, Dusan Z. and Zarić, Snežana D. and Rakić, Vesna M. and Janković, Ivana A.", year = "2014", abstract = "The surface modification of nanocrystalline TiO2 particles (45 angstrom) with catecholate-type ligands having different electron donating/electron withdrawing substituent groups, specifically 3-methylcatechol, 4-methylcatechol, 3-methoxycatechol, 3,4-dihydroxybenzaldehyde and 4-nitrocatechol, was found to alter the optical properties of nanoparticles in a similar way to catechol. The formation of the inner-sphere charge-transfer (CT) complexes results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites and a reduction of the effective band gap, being slightly less pronounced in the case of electron withdrawing substituents. The investigated ligands have the optimal geometry for binding to surface Ti atoms, resulting in ring coordination complexes of the catecholate type (binuclear bidentate binding-bridging) thus restoring six-coordinated octahedral geometry of surface Ti atoms. From the absorption measurements (Benesi-Hildebrand plot), the stability constants in methanol/water = 90/10 solutions at pH 2 in the order of 10(3) M-1 have been determined. The binding structures were investigated by using FTIR spectroscopy. Thermal stability of CT-complexes was investigated by using TG/DSC/MS analysis. Quantum chemical calculations on model systems using density functional theory (DFT) were performed to obtain the vibrational frequencies of charge transfer complexes, and the calculated values were compared with the experimental data.", journal = "Physical Chemistry Chemical Physics", title = "The effect of substituents on the surface modification of anatase nanoparticles with catecholate-type ligands: a combined DFT and experimental study", volume = "16", number = "38", pages = "20796-20805", doi = "10.1039/c4cp02197e" }
Savić, T. D., Čomor, M., Nedeljković, J., Veljkovic, D. Z., Zarić, S. D., Rakić, V. M.,& Janković, I. A.. (2014). The effect of substituents on the surface modification of anatase nanoparticles with catecholate-type ligands: a combined DFT and experimental study. in Physical Chemistry Chemical Physics, 16(38), 20796-20805. https://doi.org/10.1039/c4cp02197e
Savić TD, Čomor M, Nedeljković J, Veljkovic DZ, Zarić SD, Rakić VM, Janković IA. The effect of substituents on the surface modification of anatase nanoparticles with catecholate-type ligands: a combined DFT and experimental study. in Physical Chemistry Chemical Physics. 2014;16(38):20796-20805. doi:10.1039/c4cp02197e .
Savić, Tatjana D., Čomor, Mirjana, Nedeljković, Jovan, Veljkovic, Dusan Z., Zarić, Snežana D., Rakić, Vesna M., Janković, Ivana A., "The effect of substituents on the surface modification of anatase nanoparticles with catecholate-type ligands: a combined DFT and experimental study" in Physical Chemistry Chemical Physics, 16, no. 38 (2014):20796-20805, https://doi.org/10.1039/c4cp02197e . .