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In this manuscript, a pyridyl containing porphyrin, C46H36N8O4 (denoted as Tris@NTPP) and its derived polyoxometalate-porphyrin hybrid, [C4H9)4N]3[C41H26N7NHCO(NH)C(OCH2)3MnMo6 O18(OCH2)3C(NH)CONHN7 H26C41] (denoted as NTPP@POM) in which two pyridyl containing porphyrin moieties hanged onto one Anderson polyoxometalate, have been successfully synthesized and thoroughly characterized. Fluorescence quenching was observed in NTPP@POM as compared with its precursor Tris@NTPP inferring the transfer of electron/energy from porphyrin moiety to POM moiety. NTPP@POM showed notably enhanced nonlinear absorption (β = 2.32 × 10–5 esu) than Tris@NTPP (β = 0.73 × 10–5 esu). These NLO responses were associated with fluorescence decay mechanism which oriented the singlet excited(*S) states and triplet excited(*T) states of Tris@NTPP and NTPP@POM. Life time decay studies revealed that NTPP@POM (τ2 = 5.32 ns) were stayed for shorter time in excited triplet state than Tris@NTPP (τ2 = 10 ns), implying shorter life time led towards higher NLO responses. [ABSTRACT FROM AUTHOR]

Tetrafunctionalized porphyrins are energetic synthons to prepare MOFs(Metal organic framework) and COFs(Covalent organic framework). Herein, a new tetrafucntionalized metallo porphyrin was used and connected via amide functionality with anderson polyoxometalates(POMs) and assembled two COFs(P@Ni-AndCOF & P@Cu-AndCOF). Structures, properties and their relationships have been unlocked thoroughly by means of FT-IR, UV–visible, 1HNMR, PXRD, SEM and cyclic voltammetric(CV) spectral analysis. The catalysts were tested to uncover the photocatalytic properties such as photocurrent and photodegradation properties. P@Cu-AndCOF and P@Ni-AndCOF were used to fabricate the ITO TiO 2 coated electrodes to study optical activity, adsorption study and photocurrent generation. The adsorption study of P@Cu-AndCOF and P@Ni-AndCOF has been studied by using Langmuir and Freundlich model with calculated Langmuir constants q m , K L and R L values of about [7.44(mg/g), 8.02(mg/g)], [0.79(L/mg), 0.69(L/mg)] and (0.22 & 0.23) respectively. The correlation coefficient for adsorption obtained through Langmuir analysis were 0.92, and 0.95 for P@Ni-AndCOF and P@Cu-AndCOF respectively. The 1/n, K f and R2 values obtained from Freundlich adsorption isotherm for P@Ni-AndCOF and P@Cu-AndCOF were (0.50 & 0.52), (3.325676 mg/g &3.328971 mg/g) and (0.94 & 0.93) respectively. The bandgap values evaluated via absorption edge of UV–visible spectra for P@Ni-AndCOF and P@Cu-AndCOF in DMSO solution were 2.82eV, and 2.83eV respectively while the bandgap values calculated for ultra-thin films were 1.78eV, and 1.85eV for P@Ni-AndCOF and P@Cu-AndCOF correspondingly. The calculated real, imaginary dielectric constants, Urbach edge, refractive index values and the electrical conductivity for ultra-thin film of P@Ni-AndCOF and P@Cu-AndCOF were (1.4x104-1.41x104& 2.19x10−9-2.45x10−9), (6.6x104-7.4x104&1.7x10−10-2.47x10−10), (0.323eV & 0.362eV), (32.9–32.4 & 33–30.4) and (5.8 × 104-2.9 × 104 &6.1 × 104-4.7 × 103 S/m) respectively. Furthermore, photodegradation activity of both catalysts was checked in Methylene-Blue(MB) and Rhodamine B(Rh-B) dyes under 3 W light. They showed higher photocatalytic efficiency for MB than that for Rh-B caused degradation efficiency of 89% and 79.3% for MB and 83% and 71.3% for Rh-B respectively after 660min. The photodegradation activity was also observed in dyes solutions along with some scavenger's ammonium oxalate (AO, h+-scavenger) and isopropanol (ISOP, •OH-scavenger) and it was observed that by the addition of these scavengers photodegradation rate was reduced. [Display omitted] • Two COFs (P@Ni-AndCOF & P@Cu-AndCOF) Structures have been synthesized from a new tetrafucntionalized metallo porphyrin attached via amide functionality with Anderson polyoxometalates(POMs). • The catalysts were tested to uncover the photocatalytic applications such as photocurrent generation properties of ITO TiO 2 coated electrodes (optical activity, adsorption study and photocurrent production) and photodegradation properties (in MB and Rh-B dyes and along with ammonium oxalate (h+) and isopropanol (•OH) scavengers under 3watt light). • The adsorption study was done using Langmuir and Freundlich model. The calculated real, imaginary dielectric constants, Urbach edge, refractive index values and the electrical conductivity for ultra-thin films were also calculated under different intensities of light. • Both catalysts showed higher photocatalytic efficiency for MB than that for Rh-B after 660min time interval. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two previously synthesized porphyrin and pom hybrids have been used. • Third order NLO properties studied. • T-TriPP@WDP and DiT-DiPP@DiWDP bearing one and two Wells-Dawson type polyoxometalates (POMs) respectively, have been considered regarding their fluorescence lifetime decay studies in comparison of third order non-linear optical (NLO) activities. • The results showed that DiT-DiPP@Di-WDP possessing the superlative response for NLO properties and lifetime decay than T-TriPP@WDP by exhibiting greater NLO properties (β = 2.90, γ = 12.91, χ3 = 2.56, Imχ (3) = 3.73) and shorter lifetime decay values (τ1 = 1.09 & τ2 = 4.22). Presenting quick intersystem crossing (ISC) development by shifting their energy from singlet to triplet excited-states. Two previously synthesized porphyrin-polyoxometalate hybrids as [(C 4 H 9) 4 N)] 5 H[COHNC(CH 2 O) 3 P 2 V 3 W 15 O 59 {C 44 H 29 N 4 }]·CH 3 CN and [(C 4 H 9) 4 N] 10 H 2 [{COHNC(CH 2 O) 3 P 2 V 3 W 15 O 59 } 2 C 44 N 4 H 28 ]·CH 3 CN symbolized as T-TriPP@WDP and DiT-DiPP@DiWDP bearing one and two Wells-Dawson type polyoxometalates (POMs) respectively, have been considered regarding their fluorescence lifetime decay studies in comparison of third order non-linear optical (NLO) activities. The results showed that DiT-DiPP@Di-WDP possessing the superlative response for NLO properties and lifetime decay than T-TriPP@WDP by exhibiting greater NLO properties (β = 2.90, γ = 12.91, χ3 = 2.56, Imχ (3) = 3.73) and shorter lifetime decay values (τ 1 = 1.09 & τ 2 = 4.22). Presenting quick intersystem crossing (ISC) development by shifting their energy from singlet to triplet excited-states. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesized alpha-ADPOM@3Py • Characterized through various analytical techniques. • Determination and comparision of some of NLO parameters by using z-scan measurements. • Determined the singlet and triplet state by using electrochemical studies. Nonlinear optical (NLO) materials are essential components in modern photonics and optical devices due to their ability to generate new frequencies through the nonlinear interaction with intense light. Synthesizing porphyrin-based NLO materials is complex and challenging, requiring specialized techniques to achieve high purity and yield. Controlling chromophore orientation and optimizing nonlinear optical properties are key difficulties that demand interdisciplinary efforts for practical photonics and optical applications. In the present study by using z-scan technique some of non-linear optical (NLO) parameters includingthird order NLO susceptibility (χ3), and molecular second hyperpolarizability (γ) have been determined and compared with already synthesized Anderson containing POMs-porphyrin hybrids to study the effect of substituent, and linker length. The alpha-ADPOM@3Pyshows remarkable NLO response in comparison to that of NTPP@3Py. In comparison with other POMs-porphyrin hybrids it has been proposed that alpha-ADPOM@3Py has lower band gap, shorter linker length, and close proximity than that of others, therefore it shows more delocalization in the porphyrin core and hence remarkable NLO response. The calculated E(CS) charge separated state of alpha-ADPOM@3Py is found to be 0.85 eV which is responsible for facile transfer of electrons from porphyrin moiety to alpha-ADPOM. [ABSTRACT FROM AUTHOR]