Micro-homogeneous solvent mixtures of propyl acetate (PA)/butyronitrile (BN) allow for a systematic variation of the static dielectric constants, s , in the range from to . The mixtures of toluene (TO)/dimethylsulfoxide (DMSO) with varying the s values in the range from to are used as micro-heterogeneous binary solvents. In micro-heterogeneous environment, DMSO molecules get preferentially favoured in the solvation shell, forming micro-clusters surrounding the solute molecules. This solvation effect is reflected in the altered magnetic field effects, lifetimes and dissociation rate constants of the exciplexes. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 19, SOÁ T4 - 2016 Magnetic field effect on exciplex-forming organic acceptor/donor system: a powerful tool for understanding the preferential solvation Hoang Minh Hao University of Technology and Education, Ho Chi Minh City Pham Thi Bich Van Nong Lam University, Ho Chi Minh City (Received on June 5th 2015, accepted on 26th September 2016 ) ABSTRACT Many acceptor/donor systems can form (PA)/butyronitrile (BN) allow for a systematic excited-state charge-transfer complexes variation of the static dielectric constants, s , in (exciplexes) in photo-induced electron transfer the range from to . The mixtures of reactions. Exciplex can be detected by their toluene (TO)/dimethylsulfoxide (DMSO) with luminescence. In addition, the exciplex varying the s values in the range from to luminescence is magneto-sensitive. Here, we are used as micro-heterogeneous binary employ an approach based on the magnetic field solvents. In micro-heterogeneous environment, effect on the exciplex of 9,10DMSO molecules get preferentially favoured in dimethylanthracene/N,N-dimethylaniline pair in the solvation shell, forming micro-clusters micro-homogeneous and micro-heterogeneous surrounding the solute molecules. This solvation binary solvents to investigate the effects of the effect is reflected in the altered magnetic field preferential solvation processes on solute effects, lifetimes and dissociation rate constants of the exciplexes. molecules in solutions. Micro-homogeneous solvent mixtures of propyl acetate Key words: Exciplex, magnetic field effect, photo-induced electron transfer, radical ion pair INTRODUCTION Exciplexes, excited-state charge-transfer complexes, are formed in bimolecular photoinduced electron transfer (PET) reactions of excited electron acceptor (A*) and electron donor (D) [1]. Fig. 1 depicts a scheme of the PET reaction in a typical exciplex forming acceptor/donor system. Here, the vertical axis refers to free .
