Pyrazoline derived new "off-on-off" fluorescent pH sensors


BOZKURT E., GÜL H. İ., Ozgun D. O.

OPTICAL MATERIALS, cilt.84, ss.550-555, 2018 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 84
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1016/j.optmat.2018.07.052
  • Dergi Adı: OPTICAL MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.550-555
  • Anahtar Kelimeler: Pyrazoline, Absorption, Fluorescence, Off-on-off fluorescent pH sensor, ACID, OPTOELECTRONICS, DERIVATIVES, COMPOUND
  • Atatürk Üniversitesi Adresli: Evet

Özet

Pyrazolines are reported with a broad range of bioactivities, excellent fluorescence properties and easy synthesis. But unfortunately, there is no or, very limited information available about their pH sensor application. Additionally, there is a little information about "off-on-off" type of pH sensors in literature. To fulfill the gap in literature and try to find out new possible "off-on-off" pH sensor, in this study it was planned to investigate the changes in the photo-physical properties of four pyrazolines D1-D4, 4-(5-(3,4-dimethoxyphenyl)-3-(4-substitutedphenyl)-4,5-dihydro-1H-pyrazol-1-yl)benzene sulfonamide, in water and different pH (2, 4, 6, 8, 9, 10, 12) in which on phenyl was H (D1), F (D2), Cl (D3) and Br (D4). The compound Dl exhibited excellent fluorescence properties and high fluorescence quantum yields in water. When the compounds D2-D4 which have electron-withdrawing substituents F, Cl and Br in D2-D4, respectively, were considered, it was observed that fluorescence quenching occurred in the molecules in question due to increased intersystem crossing probability while D1 did not show fluorescence quenching. However, the photo-physical properties of the compounds D1-D4 displayed important changes as a function of pH. It follows from these important changes that the compounds D1-D4 have "off-on-off" type of fluorescent pH sensor properties based on intramolecular charge transfer (ICT). These results indicated that these pyrazoline derivatives would be able to act as an efficient "off-on-off" fluorescent pH sensor in biological, environmental and medical etc. areas.