Abstract
Four series of new push–push–pull chromophores based on two types of heterocyclic cores, namely imidazo[5,1,2-cd]indolizines and naphtho[1′,2′:4,5]imidazo[1,2-a]pyridines, and two types of linear π spacers, namely diphenylacetylene and biphenyl, were prepared. The two isomeric heterocyclic compounds were prepared by palladium-catalyzed double C–H functionalization reactions. Further palladium-catalyzed C–C coupling reactions allow the construction of diphenylacetylene and biphenyl spacers on the chromophores. Different electron-donors including NMe2, NPh2, and OMe and CN acceptors were incorporated into the chromophores. The corresponding donor- and acceptor-free compounds were also prepared for comparative studies. In the case of chromophores with strong NMe2 or NPh2 donors, a strong intramolecular charge-transfer (ICT) process occurs leading to fluorescence emission quenching in polar solvents. The use of a slightly weaker OMe donor together with the naphtho[1′,2′:4,5]imidazo[1,2-a]pyridine core allows to obtain an intense blue fluorescence with high quantum yield of up to 0.825. DFT and TD-DFT calculations offer satisfactory explanations to the observed photophysical data.
| Original language | English |
|---|---|
| Pages (from-to) | 5975-5985 |
| Number of pages | 11 |
| Journal | European Journal of Organic Chemistry |
| Volume | 2017 |
| Issue number | 40 |
| DOIs | |
| Publication status | Published - 2017 Nov 2 |
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All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
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Synthesis and Optical Properties of Push–Push–Pull Chromophores Based on Imidazo[5,1,2-cd]indolizines and Naphtho[1′,2′:4,5]imidazo[1,2-a]pyridines. / Maitra, Ratnava; Chen, Jie Hong; Hu, Ching Han; Lee, Hon Man.
In: European Journal of Organic Chemistry, Vol. 2017, No. 40, 02.11.2017, p. 5975-5985.Research output: Contribution to journal › Article
TY - JOUR
T1 - Synthesis and Optical Properties of Push–Push–Pull Chromophores Based on Imidazo[5,1,2-cd]indolizines and Naphtho[1′,2′:4,5]imidazo[1,2-a]pyridines
AU - Maitra, Ratnava
AU - Chen, Jie Hong
AU - Hu, Ching Han
AU - Lee, Hon Man
PY - 2017/11/2
Y1 - 2017/11/2
N2 - Four series of new push–push–pull chromophores based on two types of heterocyclic cores, namely imidazo[5,1,2-cd]indolizines and naphtho[1′,2′:4,5]imidazo[1,2-a]pyridines, and two types of linear π spacers, namely diphenylacetylene and biphenyl, were prepared. The two isomeric heterocyclic compounds were prepared by palladium-catalyzed double C–H functionalization reactions. Further palladium-catalyzed C–C coupling reactions allow the construction of diphenylacetylene and biphenyl spacers on the chromophores. Different electron-donors including NMe2, NPh2, and OMe and CN acceptors were incorporated into the chromophores. The corresponding donor- and acceptor-free compounds were also prepared for comparative studies. In the case of chromophores with strong NMe2 or NPh2 donors, a strong intramolecular charge-transfer (ICT) process occurs leading to fluorescence emission quenching in polar solvents. The use of a slightly weaker OMe donor together with the naphtho[1′,2′:4,5]imidazo[1,2-a]pyridine core allows to obtain an intense blue fluorescence with high quantum yield of up to 0.825. DFT and TD-DFT calculations offer satisfactory explanations to the observed photophysical data.
AB - Four series of new push–push–pull chromophores based on two types of heterocyclic cores, namely imidazo[5,1,2-cd]indolizines and naphtho[1′,2′:4,5]imidazo[1,2-a]pyridines, and two types of linear π spacers, namely diphenylacetylene and biphenyl, were prepared. The two isomeric heterocyclic compounds were prepared by palladium-catalyzed double C–H functionalization reactions. Further palladium-catalyzed C–C coupling reactions allow the construction of diphenylacetylene and biphenyl spacers on the chromophores. Different electron-donors including NMe2, NPh2, and OMe and CN acceptors were incorporated into the chromophores. The corresponding donor- and acceptor-free compounds were also prepared for comparative studies. In the case of chromophores with strong NMe2 or NPh2 donors, a strong intramolecular charge-transfer (ICT) process occurs leading to fluorescence emission quenching in polar solvents. The use of a slightly weaker OMe donor together with the naphtho[1′,2′:4,5]imidazo[1,2-a]pyridine core allows to obtain an intense blue fluorescence with high quantum yield of up to 0.825. DFT and TD-DFT calculations offer satisfactory explanations to the observed photophysical data.
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U2 - 10.1002/ejoc.201701109
DO - 10.1002/ejoc.201701109
M3 - Article
AN - SCOPUS:85033225646
VL - 2017
SP - 5975
EP - 5985
JO - Annalen der Pharmacie
JF - Annalen der Pharmacie
SN - 0075-4617
IS - 40
ER -