Theoretical insights into the static chemical reactivity and NLO properties of some conjugated carbonyl compounds: case of 5-aminopenta-2,4-dienal derivatives

Abstract

In this paper, we are interested in the relative stabilities of the possible isomeric structures of the 5-aminopenta-2,4-dienals which arise from the various possible configurations of the conjugated carbon–carbon double bonds. All possible isomeric structures have been taken into account. Because of these derivatives are push–pull conjugated dienes, they can behave either as nucleophilic or electrophilic species and could be used for nonlinear optical (NLO) applications. We focus our attention to the static chemical reactivity of these derivatives to predict which atomic site is the most susceptible to undergo either a nucleophilic or an electrophilic attack. The calculated reactivity indices derived from density functional theory were used and various descriptors such as electrophilicity (ωk), nucleophilicity (Nk), and local reactivity difference index (Rk) are then calculated. The predictions were compared to the experimental and theoretical results. The natural bond orbital analysis was also studied. Linear and NLO properties have been investigated by the CAM-B3LYP functional. Indeed, we have been interested on the dipole moment µ, mean polarizability $${\upalpha }$$ , anisotropy polarizability $$\left| \alpha \right|$$ , the hyper-Rayleigh scattering (HRS) first hyperpolarizability $$\beta_{HRS} \left( { - 2\omega ;\omega ,\omega } \right)$$ , and the depolarization ratio (DR). An inverse relationship has been obtained between the $$\beta_{{{\text{HRS}}}}$$ and the HOMO–LUMO gaps.