Second-Order Nonlinear Optics Response of the Boron-Dipyrromethenes-Based Mislinked Expanded Porphyrins: Revealing the Role of the -BF 2 Group.

Here, the mislinked expanded porphyrins singly (labeled A ) and doubly (labeled B ) neo-confused [22]smaragdyrin, the boron-dipyrromethenes-based mislinked expanded porphyrins singly (labeled C ) and doubly (labeled D ) neo-confused [22]smaragdyrin, where both C and D include a -BF 2 group, are chosen to serve as the study objects, and theoretical calculations are carried out to study the role of the -BF 2 group in the second-order nonlinear optics (NLO) behaviors. Results highlighted that the -BF 2 group plays an important role for the second-order behaviors in mislinked expanded porphyrins; namely, embedding the -BF 2 group well enhanced the hyper-Rayleigh scattering (HRS) value {β HRS (0;0,0)}, C { β HRS ( 0 ; 0 , 0 ) } A { β HRS ( 0 ; 0 , 0 ) } = 2.0 and D { β HRS ( 0 ; 0 , 0 ) } B { β HRS ( 0 ; 0 , 0 ) } = 2.9, main owning to the fact that installing -BF 2 increases the electron delocalization degree and decreases the excited energy of the crucial excited state.