Tunable Chiral Second-Order Nonlinear Optical Chromophores Based on Helquat Dications

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F17%3A00478612" target="_blank" >RIV/61388963:_____/17:00478612 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/17:10364252

Výsledek na webu

<a href="http://dx.doi.org/10.1021/acs.jpca.7b06057" target="_blank" >http://dx.doi.org/10.1021/acs.jpca.7b06057</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpca.7b06057" target="_blank" >10.1021/acs.jpca.7b06057</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Tunable Chiral Second-Order Nonlinear Optical Chromophores Based on Helquat Dications

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

Tunable Chiral Second-Order Nonlinear Optical Chromophores Based on Helquat Dications

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Physical Chemistry A

ISSN

1089-5639

e-ISSN

—

Svazek periodika

121

Číslo periodika v rámci svazku

31

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

5842-5855

Kód UT WoS článku

000407656100009

EID výsledku v databázi Scopus

2-s2.0-85027271215