Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor

Weber L, Eickhoff D, Marder TB, Fox MA, Low PJ, Dwyer AD, Tozer DJ, Schwedler S, Brockhinke A, Stammler H-G, Neumann B (2012)
Chemistry - a European Journal 18(5): 1369-1382.

Zeitschriftenaufsatz | Veröffentlicht | Englisch
 
Download
Es wurde kein Volltext hochgeladen. Nur Publikationsnachweis!
Autor/in
; ; ; ; ; ; ; ; ; ;
Abstract / Bemerkung
Four linear π-conjugated systems with 1,3-diethyl-1,3,2-benzodiazaborolyl [C6H4(NEt)2B] as a π-donor at one end and dimesitylboryl (BMes2) as a π-acceptor at the other end were synthesized. These unusual pushpull systems contain phenylene (?1,4-C6H4?; 1), biphenylene (?4,4'-(1,1'-C6H4)2?; 2), thiophene (?2,5-C4H2S?; 3), and dithiophene (?5,5'-(2,2'-C4H2S)2?; 4) as π-conjugated bridges and different types of three-coordinate boron moieties serving as both π-donor and π-acceptor. Molecular structures of 2, 3, and 4 were determined by single-crystal X-ray diffraction. Photophysical studies on these systems reveal blue-green fluorescence in all compounds. The Stokes shifts for 1, 2, and 3 are notably large at 78209760 cm-1 in THF and 54306210 cm-1 in cyclohexane, whereas the Stokes shift for 4 is significantly smaller at 5510 cm-1 in THF and 2450 cm-1 in cyclohexane. Calculations on model systems 1'4' show the HOMO to be mainly diazaborolyl in character and the LUMO to be dominated by the empty π orbital at the boron atom of the BMes2 group. However, there are considerable dithiophene bridge contributions to both orbitals in 4'. From the experimental data and MO calculations, the π-electron-donating strength of the 1,3-diethyl-1,3,2-benzodiazaborolyl group was found to lie between that of methoxy and dimethylamino groups. TD-DFT calculations on 1'4', using B3LYP and CAM-B3LYP functionals, provide insight into the absorption and emission processes. B3LYP predicts that both the absorption and emission processes have strong charge-transfer character. CAM-B3LYP which, unlike B3LYP, contains the physics necessary to describe charge-transfer excitations, predicts only a limited amount of charge transfer upon absorption, but somewhat more upon emission. The excited-state (S1) geometries show the borolyl group to be significantly altered compared to the ground-state (S0) geometries. This borolyl group reorganization in the excited state is believed to be responsible for the large Stokes shifts in organic systems containing benzodiazaborolyl groups in these and related compounds.
Stichworte
donor-acceptor systems; density functional calculations; luminescence; diazaborole; charge transfer
Erscheinungsjahr
2012
Zeitschriftentitel
Chemistry - a European Journal
Band
18
Ausgabe
5
Seite(n)
1369-1382
ISSN
0947-6539
Page URI
https://pub.uni-bielefeld.de/record/2474460

Zitieren

Weber L, Eickhoff D, Marder TB, et al. Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor. Chemistry - a European Journal. 2012;18(5):1369-1382.
Weber, L., Eickhoff, D., Marder, T. B., Fox, M. A., Low, P. J., Dwyer, A. D., Tozer, D. J., et al. (2012). Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor. Chemistry - a European Journal, 18(5), 1369-1382. doi:10.1002/chem.201102059
Weber, L., Eickhoff, D., Marder, T. B., Fox, M. A., Low, P. J., Dwyer, A. D., Tozer, D. J., Schwedler, S., Brockhinke, A., Stammler, H. - G., et al. (2012). Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor. Chemistry - a European Journal 18, 1369-1382.
Weber, L., et al., 2012. Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor. Chemistry - a European Journal, 18(5), p 1369-1382.
L. Weber, et al., “Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor”, Chemistry - a European Journal, vol. 18, 2012, pp. 1369-1382.
Weber, L., Eickhoff, D., Marder, T.B., Fox, M.A., Low, P.J., Dwyer, A.D., Tozer, D.J., Schwedler, S., Brockhinke, A., Stammler, H.-G., Neumann, B.: Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor. Chemistry - a European Journal. 18, 1369-1382 (2012).
Weber, Lothar, Eickhoff, Daniel, Marder, Todd B., Fox, Mark A., Low, Paul J., Dwyer, Austin D., Tozer, David J., Schwedler, Stefanie, Brockhinke, Andreas, Stammler, Hans-Georg, and Neumann, Beate. “Experimental and Theoretical Studies on Organic D-π-A Systems Containing Three-Coordinate Boron Moieties as both π-Donor and π-Acceptor”. Chemistry - a European Journal 18.5 (2012): 1369-1382.

Export

Markieren/ Markierung löschen
Markierte Publikationen

Open Data PUB

Web of Science

Dieser Datensatz im Web of Science®

Quellen

PMID: 22213064
PubMed | Europe PMC

Suchen in

Google Scholar