Počet záznamů: 1
Tunable Chiral Second-Order Nonlinear Optical Chromophores Based on Helquat Dications
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SYSNO ASEP 0478612 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Tunable Chiral Second-Order Nonlinear Optical Chromophores Based on Helquat Dications Tvůrce(i) Buckley, L. E. R. (GB)
Coe, B. J. (GB)
Rusanova, D. (GB)
Joshi, Vishwas (UOCHB-X) RID
Sánchez, S. (GB)
Jirásek, Michael (UOCHB-X) RID
Vávra, Jan (UOCHB-X) RID
Khobragade, Dushant (UOCHB-X)
Severa, Lukáš (UOCHB-X) RID, ORCID
Císařová, I. (CZ)
Šaman, David (UOCHB-X) RID, ORCID
Pohl, Radek (UOCHB-X) RID, ORCID
Clays, K. (BE)
Depotter, G. (BE)
Brunschwig, B. S. (US)
Teplý, Filip (UOCHB-X) RID, ORCIDZdroj.dok. Journal of Physical Chemistry A. - : American Chemical Society - ISSN 1089-5639
Roč. 121, č. 31 (2017), s. 5842-5855Poč.str. 14 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova hyper-Rayleigh scattering ; excited states ; derivatives Vědní obor RIV CF - Fyzikální chemie a teoretická chemie Obor OECD Physical chemistry CEP GA13-19213S GA ČR - Grantová agentura ČR NV16-31156A GA MZd - Ministerstvo zdravotnictví Institucionální podpora UOCHB-X - RVO:61388963 UT WOS 000407656100009 EID SCOPUS 85027271215 DOI 10.1021/acs.jpca.7b06057 Anotace Fourteen new dipolar cations have been synthesized, containing methoxy or tertiary amino electron donor groups attached to helquat (Hq) acceptors. These Hq derivatives have been characterized as their TfO- salts by using various techniques including NMR and electronic absorption spectroscopies. UV-vis spectra show intense, relatively low energy absorptions with lambda(max) approximate to 400-600 nm, attributable to intramolecular charge-transfer (ICT) excitations. Single-crystal X-ray structures have been solved for two of the chromophores, one as its PF6- salt, revealing centrosymmetric packing arrangements (space groups Pbca and P (1) over bar). Molecular quadratic nonlinear optical (NLO) responses have been determined directly by using hyper-Rayleigh scattering (HRS) with a 800 nm laser, and indirectly via Stark (electroabsorption) spectroscopy for the low energy absorption bands. The obtained static first hyperpolarizabilities beta(0) range from moderate to large: (9-140) X 10(-30) esu from HRS in MeCN and (44-580) X 10(-30) esu from the Stark data in PrCN. The magnitude of beta(0) increases upon either extending the pi-conjugation length or replacing a methoxy with a tertiary amino electron donor substituent. Density functional theory (DFT) and time dependent DFT calculations on selected tertiary amino chromophores confirm that the low energy absorptions have ICT character. Relatively good agreement between the simulated and experimental UV-vis absorption spectra is achieved by using the CAM-B3LYP functional with the 6-311G(d) basis set. The beta(tot) values predicted by using DFT at the same level of theory are large ((472-1443) X 10(-30) esu in MeCN). Both the theoretical and experimental results show that para-conjugation between Hq and electron donor fragments is optimal, and enlarging the Hq unit is inconsequential with respect to the molecular quadratic NLO response. Pracoviště Ústav organické chemie a biochemie Kontakt asep@uochb.cas.cz ; Kateřina Šperková, Tel.: 232 002 584 ; Jana Procházková, Tel.: 220 183 418 Rok sběru 2018
Počet záznamů: 1