A Strongly Luminescent Chromium(III) ComplexAcid
- The synthesis, structure, reactivity,and photophysical properties of anovel acidic,luminescentchromium(III) complex [Cr(H2tpda)2]3+ (23+ +)bearing the tridentate H2tpda (2,6-bis(2-pyridylamino)pyridine) ligand are presented. Excitation of 23+ + at 442 nm results in strong, long-lived NIR luminescence at 782 nm in water and in acetonitrile. X-ray diffraction analysis and IR spectroscopy revealhydrogen-bonding interactions of the counter ions to the NH groups of 23+ + in the solidstate. Deprotonation of the NH groups of 23+ + by using anon-nucleophilic Schwesinger base in CH3CN switches off the luminescence. Re-protonation by using HClO4 restores the emission. In water,the pKa value of 23+ + amountsto8 .8, yet deprotonation is not reversible in the presence of hydroxide ions. Dioxygen quenches the emission of 23+ +,but to aweaker extent than expected. This is possibly due to the strong ion-pairing properties of 23+ + even in solution, reducing the energy transfer efficiency toThe synthesis, structure, reactivity,and photophysical properties of anovel acidic,luminescentchromium(III) complex [Cr(H2tpda)2]3+ (23+ +)bearing the tridentate H2tpda (2,6-bis(2-pyridylamino)pyridine) ligand are presented. Excitation of 23+ + at 442 nm results in strong, long-lived NIR luminescence at 782 nm in water and in acetonitrile. X-ray diffraction analysis and IR spectroscopy revealhydrogen-bonding interactions of the counter ions to the NH groups of 23+ + in the solidstate. Deprotonation of the NH groups of 23+ + by using anon-nucleophilic Schwesinger base in CH3CN switches off the luminescence. Re-protonation by using HClO4 restores the emission. In water,the pKa value of 23+ + amountsto8 .8, yet deprotonation is not reversible in the presence of hydroxide ions. Dioxygen quenches the emission of 23+ +,but to aweaker extent than expected. This is possibly due to the strong ion-pairing properties of 23+ + even in solution, reducing the energy transfer efficiency to O2.Deuteration of the NH groups of 23+ + approximately doubles the quantum yield and lifetime in water,demonstrating the importance of multiphoton relaxation in these NIR emitters.…
Autor*innen: | S. Otto, C. Förster, Cui Wang, Ute Resch-GengerORCiD, K. Heinze |
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Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | GDCh |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 1 Analytische Chemie; Referenzmaterialien |
1 Analytische Chemie; Referenzmaterialien / 1.2 Biophotonik | |
Verlag: | Wiley‐VCH Verlag GmbH & Co. KGaA |
Verlagsort: | Weinheim |
Jahrgang/Band: | 24 |
Ausgabe/Heft: | 48 |
Erste Seite: | 12555 |
Letzte Seite: | 12563 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | Cr(III) complex; Luminescence; Luminescence lifetime; NIR emitter; Oxygen sensor; Quantum yield; pH sensor |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
Chemie und Prozesstechnik / Chemische Charakterisierung und Spurenanalytik | |
DOI: | 10.1002/chem.201802797 |
ISSN: | 0947-6539 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 13.09.2018 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 13.09.2018 |