Fluorescence enhancement of quinolines by protonation

Essi Tervola; Khai Nghi Truong; Jas S. Ward; Arri Priimägi; Kari Rissanen

doi:10.1039/d0ra04691d

Fluorescence enhancement of quinolines by protonation

Essi Tervola, Khai Nghi Truong, Jas S. Ward, Arri Priimägi, Kari Rissanen

Materials Science and Environmental Engineering

Research output: Contribution to journal › Article › Scientific › peer-review

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Abstract

A study of the fluorescence enhancement of isoquinoline, acridine (benzo[b]quinoline) and benzo[h]quinoline is reported with six organic acids of different pKa values. Protonation was found to be an effective tool in the fluorescence enhancement of quinolines. A significant increase in the fluorescence intensity is observed only when strong acids are used, resulting in an over 50-fold increase in fluorescence with trifluoroacetic or benzenesulfonic acid and isoquinoline in a 1.5 : 1 ratio. The benzenesulfonic acid was found to be the most effective in the protonation of the bases despite its higher pKa value compared to trifluoro- and trichloroacetic acid. The X-ray crystal structures of 14 salts reveal the charge-assisted hydrogen bond O⋯N distances to vary very little, from 2.560(2)-2.714(3) Å, with the exception of the isoquinolinium benzenesulfonate where the O⋯N distance of 2.862(7) Å is caused by additional intermolecular interactions in the solid-state.

Original language	English
Pages (from-to)	29385-29393
Number of pages	9
Journal	RSC Advances
Volume	10
Issue number	49
DOIs	https://doi.org/10.1039/d0ra04691d
Publication status	Published - 12 Aug 2020
Publication type	A1 Journal article-refereed

Publication forum classification

Publication forum level 1

ASJC Scopus subject areas

General Chemistry
General Chemical Engineering

Access to Document

10.1039/d0ra04691dLicence: CC BY-NC

Fluorescence enhancement of quinolines 2020
CC BY-NC
Final published version, 1.42 MBLicence: CC BY-NC

http://urn.fi/URN:NBN:fi:tuni-202012219058Licence: CC BY-NC

CCDC 2000987: Experimental Crystal Structure Determination
Tervola, E. (Contributor), Truong, K.-N. (Contributor), Ward, J. S. (Contributor), Priimagi, A. (Creator) & Rissanen, K. (Contributor), Cambridge Crystallographic Data Centre, 4 May 2020
DOI: 10.5517/ccdc.csd.cc2555zj
Dataset
CCDC 2000980: Experimental Crystal Structure Determination
Tervola, E. (Contributor), Truong, K.-N. (Contributor), Ward, J. S. (Contributor), Priimagi, A. (Creator) & Rissanen, K. (Contributor), Cambridge Crystallographic Data Centre, 4 May 2020
DOI: 10.5517/ccdc.csd.cc2555r9
Dataset
CCDC 2000983: Experimental Crystal Structure Determination
Tervola, E. (Contributor), Truong, K.-N. (Contributor), Ward, J. S. (Contributor), Priimagi, A. (Creator) & Rissanen, K. (Contributor), Cambridge Crystallographic Data Centre, 4 May 2020
DOI: 10.5517/ccdc.csd.cc2555vd
Dataset

Red Labs for soft photonic, robotic and energy materials
Priimägi, A. (Contact), Vivo, P. (Contact) & Nonappa, N. (Contact)
Materials Science and Environmental Engineering
Facility/equipment: Facility

Cite this

@article{7c1f3692964c4a20b8a6a6ab38c0e8bb,

title = "Fluorescence enhancement of quinolines by protonation",

abstract = "A study of the fluorescence enhancement of isoquinoline, acridine (benzo[b]quinoline) and benzo[h]quinoline is reported with six organic acids of different pKa values. Protonation was found to be an effective tool in the fluorescence enhancement of quinolines. A significant increase in the fluorescence intensity is observed only when strong acids are used, resulting in an over 50-fold increase in fluorescence with trifluoroacetic or benzenesulfonic acid and isoquinoline in a 1.5 : 1 ratio. The benzenesulfonic acid was found to be the most effective in the protonation of the bases despite its higher pKa value compared to trifluoro- and trichloroacetic acid. The X-ray crystal structures of 14 salts reveal the charge-assisted hydrogen bond O⋯N distances to vary very little, from 2.560(2)-2.714(3) {\AA}, with the exception of the isoquinolinium benzenesulfonate where the O⋯N distance of 2.862(7) {\AA} is caused by additional intermolecular interactions in the solid-state. ",

author = "Essi Tervola and Truong, {Khai Nghi} and Ward, {Jas S.} and Arri Priim{\"a}gi and Kari Rissanen",

note = "Funding Information: We gratefully acknowledge nancial support from the Academy of Finland (KR: grant no. 317259; AP: grant no. 311142) and the University of Jyv{\"a}skyl{\"a}, Finland. Publisher Copyright: {\textcopyright} The Royal Society of Chemistry. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.",

year = "2020",

month = aug,

day = "12",

doi = "10.1039/d0ra04691d",

language = "English",

volume = "10",

pages = "29385--29393",

journal = "RSC Advances",

issn = "2046-2069",

publisher = "Royal Society of Chemistry",

number = "49",

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TY - JOUR

T1 - Fluorescence enhancement of quinolines by protonation

AU - Tervola, Essi

AU - Truong, Khai Nghi

AU - Ward, Jas S.

AU - Priimägi, Arri

AU - Rissanen, Kari

N1 - Funding Information: We gratefully acknowledge nancial support from the Academy of Finland (KR: grant no. 317259; AP: grant no. 311142) and the University of Jyväskylä, Finland. Publisher Copyright: © The Royal Society of Chemistry. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/8/12

Y1 - 2020/8/12

N2 - A study of the fluorescence enhancement of isoquinoline, acridine (benzo[b]quinoline) and benzo[h]quinoline is reported with six organic acids of different pKa values. Protonation was found to be an effective tool in the fluorescence enhancement of quinolines. A significant increase in the fluorescence intensity is observed only when strong acids are used, resulting in an over 50-fold increase in fluorescence with trifluoroacetic or benzenesulfonic acid and isoquinoline in a 1.5 : 1 ratio. The benzenesulfonic acid was found to be the most effective in the protonation of the bases despite its higher pKa value compared to trifluoro- and trichloroacetic acid. The X-ray crystal structures of 14 salts reveal the charge-assisted hydrogen bond O⋯N distances to vary very little, from 2.560(2)-2.714(3) Å, with the exception of the isoquinolinium benzenesulfonate where the O⋯N distance of 2.862(7) Å is caused by additional intermolecular interactions in the solid-state.

AB - A study of the fluorescence enhancement of isoquinoline, acridine (benzo[b]quinoline) and benzo[h]quinoline is reported with six organic acids of different pKa values. Protonation was found to be an effective tool in the fluorescence enhancement of quinolines. A significant increase in the fluorescence intensity is observed only when strong acids are used, resulting in an over 50-fold increase in fluorescence with trifluoroacetic or benzenesulfonic acid and isoquinoline in a 1.5 : 1 ratio. The benzenesulfonic acid was found to be the most effective in the protonation of the bases despite its higher pKa value compared to trifluoro- and trichloroacetic acid. The X-ray crystal structures of 14 salts reveal the charge-assisted hydrogen bond O⋯N distances to vary very little, from 2.560(2)-2.714(3) Å, with the exception of the isoquinolinium benzenesulfonate where the O⋯N distance of 2.862(7) Å is caused by additional intermolecular interactions in the solid-state.

U2 - 10.1039/d0ra04691d

DO - 10.1039/d0ra04691d

M3 - Article

AN - SCOPUS:85091640017

SN - 2046-2069

VL - 10

SP - 29385

EP - 29393

JO - RSC Advances

JF - RSC Advances

IS - 49

ER -

Fluorescence enhancement of quinolines by protonation

Abstract

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ASJC Scopus subject areas

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Datasets

CCDC 2000987: Experimental Crystal Structure Determination

CCDC 2000980: Experimental Crystal Structure Determination

CCDC 2000983: Experimental Crystal Structure Determination

Equipment

Red Labs for soft photonic, robotic and energy materials

Cite this