title: Deprotonation yields, pKa, and aci-nitro decay rates in some substituted o-nitrobenzaldehydes.
abstract: In this paper we report the deprotonation yields, the pKa, and decay kinetics of the aci-nitro intermediates of some substituted 2-nitrobenzaldehydes that can be used as photoactivatable caged proton compounds. The decay of the aci-nitro absorbance for 2-nitrobenzaldehyde occurs within a few nanoseconds from photoexcitation. Addition of electron donating methoxy substituents at positions 4 and 5 leads to lower deprotonation yields, higher pKa, and slower decays of the aci-nitro intermediates. On the contrary, the decay rate is accelerated by the introduction of an electron-withdrawing Cl atom at position 4 in the phenyl ring, with little influence on the deprotonation yield and pKa of the aci-nitro intermediate.
authors.affiliation: Dipartimento di Fisica, Università di Parma, Istituto Nazionale per la Fisica della Materia, Parco Area delle Scienze 7A, 43100 Parma, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Abbruzzetti
authors.forename: Mauro
authors.initials: M
authors.lastname: Carcelli
authors.forename: Dominga
authors.initials: D
authors.lastname: Rogolino
authors.forename: Cristiano
authors.initials: C
authors.lastname: Viappiani