Remarkable Enhancement in the Nonlinear Optical Responses of Porphyrins Realized by Combination with Polyoxometalates via Covalent Bonding: A Case Study

Abstract

Integrating polyoxometalates into porphyrin moieties via covalent bond is expected to be a new approach to tune and enhance the nonlinear optical responses of porphyrins. The effectiveness and efficiency of this proposal has been examined and witnessed by studying two new hybrid compounds as a prototype, namely, (, in which porphyrins acting as electron donor and Dawson type polyoxometalate acting as electron acceptor are connected via short tether through covalent bond. The new compounds are systematically characterized by means of elemental analyses, FT-IR, 1 H NMR, ESI-MS, TG/DTA, UV−vis, fluorescence emission spectra, and cyclic voltammetry measurement. Remarkably, great enhancement in reverse saturation absorption is achieved in 1 and 2 which is ca. 1 order of magnitude greater than their individual reactants. Additionally, optical-limiting thresholds are obtained being 0.484 J/cm 2 for 1 and 0.501 J/cm 2 for 2, respectively, implying their high potential as low-power optical-limiting materials.

Crystalline Porous Materials for Nonlinear Optics

“…The results show that the highly delocalized π-electron conjugation systems produced by the electron donor-acceptor of porphyrin-POM hybrid is considered to be the key to produce a strong NLO response. [183][184][185][186] [56] Copyright 2020, Royal Society of Chemistry. d) Schematic illustration of the TPI-COF with high crystallinity.…”

Organic–Inorganic Hybrids Composed of Keggin-Type [PMo10V2O40]5– Anions and Porphyrins: The Synthesis, Characterization, and Influence of Porphyrin Substituents on Optical Nonlinearities

“…Considering that porphyrins are better electron donors and POMs are excellent electron acceptors, these classes of compounds are in many ways more complementary to each other than they are similar. 37−51 Several articles have been published regarding both second-and third-order NLO studies 48,51−53 of porphyrin−POM-based compounds that were covalently 51,52 or electrostatically 47 linked. The above reports show that porphyrin−POM hybrid compounds constitute a novel class of outstanding NLO materials and are good candidates for future telecommunication, optical information processing, optical computing, optical data storage, optical fiber, and optical limiting devices due to their good NLO responses.…”

“…Following our continuous efforts in regard to NLO materials, − ,, we sought to understand the influence of porphyrin substituents on the nonlinear optical properties of organic–inorganic hybrids composed of an anionic metal–oxygen cluster that acts as an electron acceptor and a porphyrin cation that acts as an electron donor. In this paper, three electrostatically bonded organic–inorganic supramolecular hybrid compounds composed of symmetrical porphyrins bearing functional groups with different electron-donating abilities (4-pyridyl, 4-hydroxyphenyl, and 3,4-dimethoxyphenyl) and a Keggin-type [PMo 10 V 2 O 40 ] 5– anion were synthesized as prototypes with formal formulas of [C 40 H 28 N 8 ]­[H 4 PMo 10 V 2 O 40 ] 2 ( 1 ), [C 44 H 32 N 4 O 4 ]­[H 4 PMo 10 V 2 O 40 ] 2 ( 2 ), and [C 52 H 48 N 4 O 8 ]­[H 4 PMo 10 V 2 O 40 ] 2 ( 3 ) by reacting Keggin-type polyoxometalate α-H 5 [PMo 10 V 2 O 40 ] with porphyrins with molecular formulas of [C 40 H 26 N 8 ] ( 4 ), [C 44 H 30 N 4 O 4 ] ( 5 ), and [C 52 H 46 N 4 O 8 ] ( 6 ), respectively, as shown in Chart .…”

Anionic Effect of δ and χ Forms of Tris(alkoxo) Ligand Functionalized Anderson-Type Polyoxometalates on Nonlinear Optical Response of Porphyrin–POM Based Supramolecular Compounds

“…Therefore, POMs can be considered to combine with porphyrins to produce hybrids with remarkable NLO response. Indeed, our group recently carried out the research on third order NLO properties of some covalently 31,32 or electrostatically 33 bonded porphyrin−POM hybrids, 31,32,34,35…”