Spiro Rhodamine-Perylene Compact Electron Donor-Acceptor Dyads: Conformation Restriction, Charge Separation, and Spin-Orbit Charge Transfer Intersystem Crossing

Hu M., Sukhanov A. A., Zhang X., ELMALI A., Zhao J., Ji S., ...Daha Fazla

JOURNAL OF PHYSICAL CHEMISTRY B, cilt.125, sa.16, ss.4187-4203, 2021 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 125 Sayı: 16
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1021/acs.jpcb.1c02071
  • Dergi Adı: JOURNAL OF PHYSICAL CHEMISTRY B
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Applied Science & Technology Source, Aquatic Science & Fisheries Abstracts (ASFA), Chemical Abstracts Core, Chimica, Compendex, Computer & Applied Sciences, EMBASE, MEDLINE
  • Sayfa Sayıları: ss.4187-4203
  • Ankara Üniversitesi Adresli: Evet

Özet

Spiro rhodamine (Rho)-perylene (Pery) electron donor-acceptor dyads were prepared to study the spin-orbit charge transfer intersystem crossing (SOCT-ISC) in these rigid and sterically congested molecular systems. The electron-donor Rho (lactam form) moiety is attached via the N-C bond to the electron acceptor at either 1- or 3-position of the Pery moiety (Rho-Pery-1 and Rho-Pery-3). Severe torsion of the Pery moiety in Rho-Pery-1 was observed. The fluorescence of the two dyads is significantly quenched in polar solvents, and the singlet oxygen quantum yields (Phi(Delta)) are strongly dependent on solvent polarity (4-36%). Femtosecond transient absorption spectra demonstrate that charge separation (CS) takes 0.51 ps in Rho-Pery-1 and 5.75 ps in Rho-Pery-3, and the charge recombination (CR)-induced ISC is slow (>3 ns). Nanosecond transient absorption spectra indicate that the formation of triplet states via SOCT-ISC takes 24-75 ns for Rho-Pery-1 and 6-15 ns for Rho-Pery-3, and the distorted p-framework of the Pery moiety results in a shorter triplet lifetime of 19.9 vs 291 mu s for the planar analogue. Time-resolved electron paramagnetic resonance spectroscopy confirms the SOCT-ISC mechanism.