Investigation of Regulating Third-Order Nonlinear Optical Property by Coordination Interaction

Abstract

In this paper, a series of organic compounds (L1–L6) with a D-π-A conjugation system were prepared. The investigations of third-order nonlinear optical (NLO) properties indicate that L1–L6 show different degrees of third-order NLO responses. It is surprising that introducing metal ions can effectively regulate their third-order NLO properties and even change the type of nonlinear absorption signal from reverse saturable absorption to saturable absorption, which can be attributed to the formation of coordination bonds between metal ions and L1–L6. It has aroused our tremendous interests in regulating third-order NLO performance. The regulation mechanisms were also discussed through the pump–probe measurements and the density functional theory. The enhancement of electron transfer efficiency is considered to be the key to improving NLO performance. Furthermore, we also obtained two coordination complexes [Cu­(L1)2­(NO3)2] (1) and [Cd­(L1)2­I2] (2) based on L1, which further proved the coordination between metal ions and L1–L6. Ligand-to-metal or metal-to-ligand charge transfer makes more electronic delocalization, leading to better third-order NLO properties. This work provides new ideas and explorations for the excogitation of third-order NLO materials.

An insight into phenomenal optical non‐linearities arising from synergistic relationship between selected BODIPYs and noble metal nanoparticles

“…[28] Hybridization of NLO active material leads to an improvement of its property by an order while keeping the ultrafast response unchanged. [41][42][43][44][45][46][47] Here, an attempt was made to improve the OL properties of one of BODIPY under study. Compound named C was chosen for organic part of the hybrid system as it exhibits comparatively better non-linearity.…”

Designable Al32‐Oxo Clusters with Hydrotalcite‐like Structures: Snapshots of Boundary Hydrolysis and Optical Limiting

“…Besides, AlOC‐52 possessed more types of π⋅⋅⋅π interactions than that in AlOC‐50 (Figure S52, Table S16). Therefore, π⋅⋅⋅π accumulation may contribute more electronic delocalization and further lead to better NLO behaviors [31] …”

“…Therefore, p•••p accumulation may contribute more electronic delocalization and further lead to better NLO behaviors. [31]…”

Unlocking the Remarkable Influence of Intramolecular Group Rotation for Third‐order Nonlinear Optical Properties

“…[6][7][8][9][10][11] Therefore, the NLO molecules design strategy is usually to extend the π-conjugation length or introduce strong electron donor/acceptor groups. [12][13][14][15][16] With the further development of research, more and more influencing factors have been studied and discovered, such as twisted π-conjugated structure, planarity of the π-center and deprotonation, etc. [17][18][19][20][21][22] However, these studies mostly focus on the direct design and modification of NLO molecules, and the influence of intramolecular group rotation on NLO properties has not been studied.…”

“…In previous reports, third‐order NLO molecules usually contain the large delocalized π‐electron cloud, which will make the π→π* transition and local charge excitation easier, leading to a certain degree of energy and charge transfer, and generating nonlinear optical behavior [6–11] . Therefore, the NLO molecules design strategy is usually to extend the π‐conjugation length or introduce strong electron donor/acceptor groups [12–16] . With the further development of research, more and more influencing factors have been studied and discovered, such as twisted π‐conjugated structure, planarity of the π‐center and deprotonation, etc [17–22] .…”