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Synthesis of Pyridazine Derivatives by Suzuki-Miyaura Cross-Coupling Reaction and Evaluation of Their Optical and Electronic Properties through Experimental and Theoretical Studies
摘要： A series of π-conjugated molecules, based on pyridazine and thiophene heterocycles 3a–e, were synthesized using commercially, or readily available, coupling components, through a palladium catalyzed Suzuki-Miyaura cross-coupling reaction. The electron-deficient pyridazine heterocycle was functionalized by a thiophene electron-rich heterocycle at position six, and different (hetero)aromatic moieties (phenyl, thienyl, furanyl) were functionalized with electron acceptor groups at position three. Density Functional Theory (DFT) calculations were carried out to obtain information on the conformation, electronic structure, electron distribution, dipolar moment, and molecular nonlinear response of the synthesized push-pull pyridazine derivatives. Hyper-Rayleigh scattering in 1,4-dioxane solutions, using a fundamental wavelength of 1064 nm, was used to evaluate their second-order nonlinear optical properties. The thienylpyridazine functionalized with the cyano-phenyl moiety exhibited the largest first hyperpolarizability (β = 175 × 10?30 esu, using the T convention) indicating its potential as a second harmonic generation (SHG) chromophore.
关键词： pyridazine,Density Functional Theory (DFT),Nonlinear optics (NLO),Second Harmonic Generators (SHG),Suzuki-Miyaura coupling
更新于2025-09-23 15:21:21
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The fabrication of Au/Pd plasmonic alloys on UiO-66-NH <sub/>2</sub> : an efficient visible light-induced photocatalyst towards the Suzuki Miyaura coupling reaction under ambient conditions
摘要： Visible light harvesting by heterogeneous photocatalysts and their applications in organic transformation reactions for the synthesis of target molecules are quite demanding science in the current scenario. In this regard, herein, a novel metal (Au/Pd)-functionalized metal organic framework (UiO-66-NH2) was synthesized to carry out the Suzuki–Miyaura coupling (SMC) reaction under visible light irradiation at ambient conditions. In order to justify the claim regarding the formation of alloys, crystallinity, morphology, particle size, proper separation of excitons, elemental content and their environment, various sensitive characterization techniques such as XRD, XPS, HRTEM, BET surface area and UV-vis analysis were employed. A mechanistic approach by means of experimental investigations revealed that the strong LSPR effect of Au facilitated the transfer of electrons to the Pd surface to make the surface negatively charged and suitable for the activation of aryl halides. The formed electropositive Au nanoparticles were converted to Au0 by accepting the photo-induced electrons from pristine UiO-66-NH2 and made available only holes at VB for the activation of phenylboronic acid. Among all the synthesized photocatalysts (1 : 2), Au/Pd@UiO-66-NH2 showed the highest activity (>99%) with TOF = 426 h?1 in an EtOH/H2O medium towards the SMC reaction, and the highest activity of this catalyst was supported by the electron gas model, LSPR effect (UV-vis) and active species separation (PL) analysis. The bimetallic noble nanoparticle-anchored UiO-66-NH2 not only expands the synthesis scope of C–C coupling by the SMC reaction under ambient conditions but will also inspire the further exploration of the activation of various reactants towards a wide range of organic transformation reactions.
关键词： visible light harvesting,Suzuki–Miyaura coupling,heterogeneous photocatalysts,LSPR effect,Au/Pd-functionalized metal organic framework
更新于2025-09-12 10:27:22
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Pd2+-conjugated reduced graphene oxide as a highly efficient visible-light-induced photocatalytic Suzuki-Miyaura coupling
摘要： In this work, we investigated Pd2+- and Pd0-loaded graphene oxide (GO) and reduced graphene oxide (r-GO) as water-soluble, visible-light-responsive photocatalysts for the Suzuki-Miyaura C-C coupling reaction. Nanosheets of r-GO (~ 200 nm) were found to be a more desirable substrate than GO nanosheets, since the corresponding catalyst showed higher activities than those of the GO catalysts in both the visible-light-induced and thermal-reactions. Furthermore, Pd2+-loaded GO and r-GO show higher catalytic activities than those of Pd0-loaded GO and r-GO because of the more efficient oxidative addition to Pd2+ compared with that to Pd0. Systematic studies under dark and light conditions demonstrated the synergic contributions of photoexcited electron transfer and the strong photothermal effect of r-GO. Pd2+- and Pd0-loaded r-GO show four-times higher photocatalytic activities compared to those of Pd0-MoS2 and Pd0-WS2 catalysts for the Suzuki-Miyaura C-C coupling reaction.
关键词： Suzuki-Miyaura coupling,reduced graphene oxide,Pd2+-conjugated reduced graphene oxide,graphene oxide,visible-light-induced photocatalytic
更新于2025-09-10 09:29:36