Statistics and administrative policy

Excited singlet (S1) state interactions of 2,2′- and 4,4′-biphenyldiols with chloroalkanes: Photoinduced dissociative electron transfer

“…This is expected because the diols are very prone to oxidation 18,24 and the CAs are known to be good electron acceptors. 29,33 An alternative mechanism, namely, the energy transfer from the S 1 state of diols to the CAs, seems to be quite unlikely as the CAs do not have any absorption at the wavelength regions of the diol emission, a foremost criteria to have the energy transfer process feasible.…”

“…17 These molecules are present in oils and oil derivatives and are reported to have antioxidant properties. 18 Biphenyldiols are formed during the metabolism of biphenyl derivatives and are reported to be photochemically active. 19 Recently, we have reported the excited singlet ͑S 1 ͒ and triplet ͑T 1 ͒ state characteristics and the photoionization behavior of 2,2Ј-and 4,4Ј-biphenyldiols in different protic and aprotic solvents, with a special impor-tance to the role of the presence and the absence of intramolecular hydrogen bonding in the two respective molecules.…”

“…[20][21][22][23] It has been observed that the photochemical behavior of 2,2Ј-biphenyldiol differs significantly from that of its 4,4Ј-analogue due to the presence and the absence of the intramolecular hydrogen bonding in two respective diols. [20][21][22][23] Since the diols are very prone to oxidation, 18,24 in the present work we have investigated the ET interactions of 2,2Ј-and 4,4Ј-biphenyldiols in their S 1 state with chloroalkane ͑CA͒ acceptors, like carbon tetrachloride ͑CCl 4 ͒, chloroform ͑CHCl 3 ͒, and methylene dichloride ͑CH 2 Cl 2 ͒, using both steady-state ͑SS͒ and time-resolved ͑TR͒ fluorescence quenching measurements. The chemical structures of the two diols are shown in Scheme 1:…”

Triplet-State Characteristics and Photoionization Behavior of 2,2‘- and 4,4‘-Biphenyldiol Studied by 248 nm Laser Flash Photolysis in Aqueous Solutions

“…17 These dihydroxy compounds are present in oils and oil derivatives and are reported to be good antioxidants. 18 Biphenyldiols are formed during the metabolism of biphenyl derivatives and are also reported to be photochemically active. 19 Because of the possibilities of both intra-and intermolecular hydrogen bonding, these molecules often show interesting chemical and photochemical properties.…”

“…Recently, we have investigated the triplet-state characteristics of the two diols in different organic solvents using a nanosecond laser flash photolysis (LFP) technique and observed substantial differences in their behavior. Because the photochemical behavior of phenols and related molecules in aqueous solutions is more important, − in the present work, we have investigated the triplet-state and PI/photodissociation (PD) characteristics of the two diols in aqueous solutions under different pH conditions. The aim of this work is to understand in detail how the presence and absence of the intramolecular hydrogen bonding in the two biphenyldiols affect their photochemical behavior in aqueous solutions under 248 nm laser excitation.…”