Design of zinc porphyrin‐perylene diimide donor‐bridge‐acceptor chromophores for large second‐order nonlinear optical response: A theoretical exploration

Abstract

The electronic structures and second‐order nonlinear optical (NLO) properties of a series of zinc porphyrin (ZnP)‐perylene diimide (PDI) donor‐bridge‐acceptor (D‐π‐A) molecules have been investigated using density functional theory (DFT) and time‐dependent DFT (TDDFT). The results show that these compounds possess excellent second‐order NLO properties and large static first hyperpolarizabilities (β0) values on the order of 103 – 104 esu−30. A DFT benchmark calculation of β0 value was first performed, confirming the optimally tuned range‐separated functionals (LC‐BLYP* and ωB97X*) can produce similar magnitudes for β0 as Møller–Plesset second‐order perturbation (MP2) calculations. The magnitudes of β0 values were studied as a function of different types of bridges: oligo‐p‐phenylenevinylene (OPV), carbon‐bridged oligo‐p‐phenylenevinylene (COPV), oligo‐thienylenevinylene (OTV), carbon‐bridged oligo‐thienylenevinylene (COTV), and also the length of π‐bridges. The calculated β0 values were found to be inversely related to the bond length alternation (BLA) values of various π‐bridges. Next, we found that the static β0 value of designed ZnP‐COTV1‐PDI molecule can be significantly enhanced by finely tuning the dihedral angles between the π‐bridge and ZnP donor or PDI acceptor. The calculated β0 value is also sensitive to the substitution positions of PDI, that is, ortho‐(α‐), bay‐(β‐), nitrogen‐(N‐). A two‐level model was proven to be useful for the qualitative description of the β0 values and further the substantial oscillator strength and the difference in transition dipole moments between the ground and excited state mainly contribute to the large β0 values. The presented work will be beneficial for potential applications of the ZnP‐PDI‐based chromophores in the optoelectronic devices and high‐performance NLO materials.

Click reactions to prepare symmetrical and asymmetrical and broad-band near-infrared absorbing dyes

“…[10][11][12][13][14][15][16] What's more, to further improve the nonlinear optical properties, third-order nonlinear optical materials could increase the optical absorption intensity and broaden the light absorption range. [17][18][19][20][21] Meanwhile, due to their one-step method, high yield, generally stable products, and easy product purification, [2+2] click reactions have attracted much attention. Moreover, formal [2+2] cycloaddition-cycloreversion reactions can be combined with click chemical reagents (tetracyanoethylene (TCNE), 7,7,8,8-tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ)) to prepare a series of nonplanar, p-conjugated, donor-acceptor chromophores.…”

“…10–16 What's more, to further improve the nonlinear optical properties, third-order nonlinear optical materials could increase the optical absorption intensity and broaden the light absorption range. 17–21…”

Enhanced non-linear optical properties of porphyrin-based polymers covalently functionalized with graphite phase carbon nitride

“…Meanwhile, due to the structural adjustability, unique electronic and photophysical properties of porphyrins, porphyrins have broad application in various areas and good prospects ( Zhang et al, 2018 ; Chen et al, 2020 ; Asghar et al, 2021 ; Liu and Cheng, 2021 ). Particularly, the NLO performance of porphyrins could be improved by the flexible modification of peripheral substituents or the hybridization with other materials ( Zawadzka et al, 2013 ; Woller et al, 2016 ; Hu et al, 2018 ; Biswal et al, 2019 ; Samal et al, 2019 ; Liu J. L. et al, 2020 ; Liu Z. et al, 2020 ; Liu and Cheng, 2021 ; Ramasamy et al, 2022 ). However, previous research indicated the self-aggregate behavior of porphyrins could lead to the formation of large macro-scale and fractal structures, causing a negative impact in the development of NLO devices in practice ( Kalachyova et al, 2014 ).…”

Benchmark study of ionization potentials and electron affinities of armchair single-walled carbon nanotubes using density functional theory

“…In our previous work we also have demonstrated the accuracy and efficiency of this optimal tuning approach served as a reliable theoretical tool for a series of molecular properties. For example, through applying the optimally-tuned long-range corrected functionals, significant improvement is found for the prediction of the IPs, EAs and transport gap of πconjugated thiophene-based oligomers and polymers [38,50], nucleobase clusters [28], organic molecular crystals [29,51]; hyperpolarizabilities of 'push-pull' systems [52,53], and excitation energies of various organic fluorescence molecules [54][55][56][57]. Since the research of CNTs has rapidly become a hotspot in both academic and industry, there is still lack of a theoretical method that can provide quantitative prediction of properties of CNTs but with relatively low computational cost.…”