TY - JOUR

T1 - Fluorinated 2,3-diaminophenazines: synthesis, mechanism of formation, and properties

AU - Li, Jiayao

AU - Krasnov, Vyacheslav

AU - Karpova, Elena

AU - Andreev, Rodion

AU - Genaev, Alexandr

AU - Rumyantseva, Elizabeth

AU - Shundrina, Inna

AU - Romanov, Vasily

AU - Selivanova, Galina

N1 - The investigation was carried out with the financial support of the Ministry of Education and Science of the Russian Federation (Project FWUE-2022-0002). Jiayao Li thanks the China Scholarship Council for financial support. Authors would like to acknowledge the Multi-Access Chemical Research Center SB RAS for spectral and analytical measurements.

PY - 2023/9/29

Y1 - 2023/9/29

N2 - A series of new fluorinated 2,3-diaminophenazines were obtained by the oxidation of fluorinated o-phenylenediamines with iron trichloride in water acidified with HCl. Isomeric 2,3-diaminophenazines with F atoms in both benzene fragments were obtained when o-phenylenediamines contained an F atom at the ortho-position with respect to the amino group. The ratio of isomers depends on the number and position of F atoms in o-phenylenediamines. DFT calculations for the formation of fluorinated 2,3-diaminophenazines in question were consistent with the experimentally observed ratio of the isomers. The formation of the predominant isomer was attributed to the action of the amino group with the highest N-charge of protonated o-phenylenediamines at the most electron-depleted position of the most stable protonated diimine. New compounds were characterized using various spectroscopy techniques (IR, UV, 1H, 19F, 13C NMR, and mass). Fluorinated 2,3-diaminophenazines are heat-resistant and fluoresce from green to red depending on the number of F atoms in the ring bearing amino groups. The presence of F atoms decreases the emission intensity but at the same time bathochromically shifts the fluorescence maximum. In the absence of the F atom in the ring bearing amino groups, fluorinated 2,3-diaminophenazines exhibited fluorescence intensities comparable to those of a non-fluorinated analog.

AB - A series of new fluorinated 2,3-diaminophenazines were obtained by the oxidation of fluorinated o-phenylenediamines with iron trichloride in water acidified with HCl. Isomeric 2,3-diaminophenazines with F atoms in both benzene fragments were obtained when o-phenylenediamines contained an F atom at the ortho-position with respect to the amino group. The ratio of isomers depends on the number and position of F atoms in o-phenylenediamines. DFT calculations for the formation of fluorinated 2,3-diaminophenazines in question were consistent with the experimentally observed ratio of the isomers. The formation of the predominant isomer was attributed to the action of the amino group with the highest N-charge of protonated o-phenylenediamines at the most electron-depleted position of the most stable protonated diimine. New compounds were characterized using various spectroscopy techniques (IR, UV, 1H, 19F, 13C NMR, and mass). Fluorinated 2,3-diaminophenazines are heat-resistant and fluoresce from green to red depending on the number of F atoms in the ring bearing amino groups. The presence of F atoms decreases the emission intensity but at the same time bathochromically shifts the fluorescence maximum. In the absence of the F atom in the ring bearing amino groups, fluorinated 2,3-diaminophenazines exhibited fluorescence intensities comparable to those of a non-fluorinated analog.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85174406861&origin=inward&txGid=32bc9d639ff3e94d9ed874bc0bbb82e8

UR - https://www.mendeley.com/catalogue/55b7ac76-5da1-3309-b0b1-08c769bc4711/

U2 - 10.1039/d3nj02875e

DO - 10.1039/d3nj02875e

M3 - Article

VL - 47

SP - 19556

EP - 19568

JO - New Journal of Chemistry

JF - New Journal of Chemistry

SN - 1144-0546

IS - 42

ER -