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Boosting water oxidation kinetics of BiVO4 through a metal-organic co-catalyst enriched with phosphate groups (Co,Fe-NTMP): Insights from lmct mechanism and DFT study

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APPLIED CATALYSIS B-ENVIRONMENT AND ENERGY 2025年 370卷

作者： Saad, Alaa Magdy Mady, Amr Hussein Sayed, Mostafa Saad Kim, Gayeong Kim, Minkyu Kim, Woo Kyoung Yeungnam Univ Sch Chem Engn Gyongsan 38541 Gyeongbuk South Korea Egyptian Petr Res Inst Petrochem Dept Nasr City 11727 Cairo Egypt Egyptian Petr Res Inst Anal & Evaluat Dept Nasr City 11727 Cairo Egypt

The primary challenges of BiVO4 include its poor stability and inefficient electron-hole pair separation. To enhance BiVO4 photoanode oxygen evolution reaction (OER), a Co,Fe- nitrilotris (methylene phosphonic acid) (Co,Fe-NTMP) metal-organic co-catalyst was developed and applied to the BiVO4 photoelectrode surface using the SILAR technique. The proposed approach significantly improved charge separation and transfer. The optimized BiVO4/Co,Fe-NTMP photoanode exhibited a current density of 2.6 mA cm-2 at 1.23 V vs. RHE, representing more than a fivefold increase compared to bare BiVO4 (0.5 mA cm-2 at 1.23 V vs. RHE) under illumination of AM 1.5 G without a sacrificial agent. Additionally, the applied bias photon-to-current efficiency (ABPE) of BiVO4/Co,Fe-NTMP reached 0.58 % at 0.83 V vs. RHE. The Delta OCP measurements indicated improved band bending and enhanced charge separation following the Co,Fe-NTMP coating. The BiVO4/Co,Fe-NTMP photoanode also demonstrated remarkable stability for 9000 s, which can attributed to the formation of ligandto-metal charge transfer (lmct), which facilitates efficient electron transport. This mechanism was substantiated by XPS and DFT analyses.

关键词： Photoelectrochemical Metal-organic complex Hydrogen production lmct BiVO4

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Extend of Ligand-Metal Charge Transfer (lmct) Deciding Multi-Responsive Colourimetric Sensing of Mn(II)/Mn(III)/Pb(II) by a Squaramide Ligand

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CHEMISTRYSELECT 2025年第17期10卷

作者： Lasitha, P. Patwari, G. Naresh NIT Goa Dept Appl Sci Goa 403703 India Indian Inst Technol Dept Chem Mumbai 400076 India

Manganese sensing using ligands remains challenging due to the stability of manganese complexes and disproportionation reactions in solvents. Herein, we report colourimetry-based fast and reliable differential sensing of Mn(II), and Mn(III), using squaramide-ligands with pyridine functionality colourimetrically. The sensing efficiency of these ligands is contingent on the disposition of the pyridine nitrogen relative to the squaramide ring and is sustained by the presence of acetate ions. The electronic and 1H-NMR measurements depict the complexation of metal ion and ligand molecules. In contrast, the electron paramagnetic resonance (EPR) measurements suggest that the extent of ligand-to-metal charge transfer (lmct) is primarily responsible for the differential sensing of Mn(II) and Mn(III) with different colours. The ligand also produces selective chromogenic responses for Pb(II) ions. The limit of detection (LOD) for the Mn(II) and Mn(III) ions is approximate to 52 n and 84 nM, respectively, where the LOD for the Pb(II) ions is 17.9 n. Visually, ligand response to below 10 mu concentration and using filter paper as low as < 1 can be easily sensed, which can be used as portable strips for real-life samples.

关键词： Colourimetric sensor lmct Mn(II)/Mn(III) and Pb(II) ions Multianalyte Squaramide ligand

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Terminal-selective C（sp3）–H borylation of unbranched alkanes enabled by intermolecular radical sampling and lmct photocatalysis

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National Science Review 2024年第5期11卷 96-98页

作者： Zhexuan Lei Jie Wu Department of Chemistry National University of Singapore

The selective functionalization of C（sp3）–H bonds with subtle differences in alkanes is highly sought after due to its atom-and step-efficiency. The activation of C（sp3）–H bonds through hydrogen atom transfer （... 详细信息

关键词： terminal enabled lmct alkanes borylation intermolecular photocatalysis radical sampling selective

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Terephthalate acid decorated TiO2 for visible light driven photocatalysis mediated via ligand-to-metal charge transfer (lmct)

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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 2020年 603卷 125188-125188页

作者： Chen, Xiangyan Peng, Xin Jiang, Longbo Yuan, Xingzhong Zhang, Jin Yu, Hanbo Hunan Normal Univ Coll Chem & Chem Engn Changsha 410081 Peoples R China Hunan Univ Coll Environm Sci & Engn Changsha 410082 Peoples R China Hunan Univ Key Lab Environm Biol & Pollut Control Minist Educ Changsha 410082 Peoples R China

A novel terephthalate acid (TPA) and TiO2 system was developed by chemically bonding between the -COOH groups on TPA and -OH groups on the surface of TiO2 under hydrothermal conditions. The crystallization, morphology and photochemical properties of TiO2-TPA were studied by XRD, FTIR, XPS, TEM, UV-vis absorption spectroscopy measurements, respectively. The prepared TiO2-TPA nanoparticles exhibited excellent photoactivity under visible light by a ligand-metal charge transfer (lmct) mechanism. Even though TPA is often used as a ligand for titanium-organic frameworks, there has been no report about the fact that TiO2-TPA is capable of forming an lmct complex. The optimized TiO2-TPA (molar ratio of 0.5) composite showed a superior photodegradation than TiO2. The removal rate of Rhodamine B (RhB) was 94.10 % in 60 min, which were 31.3 times than that of pure TiO2 (3.34 %). The result indicated that TiO2 and TPA had tight synergistic effect. In detail, TPA-modified composite showed a smaller band gap and stronger light respond under visible range. Meanwhile, the charge transfer from TPA to TiO2 reduced the recombination rate of electron holes.

关键词： Surface modification Photocatalysis Titaniumdioxide Terephthalate Acid lmct

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Role of lmct States in Luminescence Excitation Processes in Europium Indolecarboxylates

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OPTICS AND SPECTROSCOPY 2023年第10期131卷 1103-1111页

作者： Tsaryuk, V. I. Zhuravlev, K. P. Russian Acad Sci Kotelnikov Inst Radio Engn & Elect Fryazino Branch Fryazino Moscow Oblast Russia

The luminescence excitation energy transfer in europium and terbium indole-3-carboxylates, indole-3-acetates and indole-3-propionates as well as ternary indolecarboxylates containing 1,10-phenanthroline and 2,2'-bipyridine molecules have been studied. The luminescence excitation spectra, the lifetimes of the 5D0 (Eu3+) and 5D4 (Tb3+) states, and the luminescence intensity are analyzed. The decisive role of ligand-metal charge transfer (lmct) states in the quenching of the luminescence of europium aromatic carboxylates containing a pi-excessive pyrrole or indole fragment is demonstrated. Most europium compounds are characterized by quenching due to the depopulation of the 5D0 state of the Eu(3+ )ion through the low-energy lmct state. But in some ternary compounds, the lmct state being of higher energy participates in the nonradiative depopulation of the excited electronic states of the ligand.

关键词： luminescence Eu3+ Tb3+ lmct indolecarboxylate pi-excessive heterocycle

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Visible-Light-Induced Vicinal Dichlorination of Alkenes through lmct Excitation of CuCl2

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ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 2020年第52期59卷 23603-23608页

作者： Lian, Pengcheng Long, Wenhao Li, Jingjing Zheng, Yonggao Wan, Xiaobing Soochow Univ Coll Chem Chem Engn & Mat Sci Key Lab Organ Synth Jiangsu Prov 199 Ren Ai Rd Suzhou 215123 Jiangsu Peoples R China

This work demonstrates photoredox vicinal dichlorination of alkenes, based on the homolysis of CuCl2 in response to irradiation with visible light. This catalysis proceeds via a ligand to metal charge transfer process and provides an exciting opportunity for the synthesis of 1,2-dichloride compounds using an inexpensive, low-molecular-weight chlorine source. This new process exhibits a wide substrate scope, excellent functional group tolerance, extraordinarily mild conditions and does not require external ligands. Mechanistic studies show that the ready formation of chlorine atom radicals is responsible for the facile formation of C-Cl bonds in this synthetic process.

关键词： alkenes cupric chloride dichlorination lmct photoredox

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Iron-Catalyzed Photoinduced lmct: A 1° C-H Abstraction Enables Skeletal Rearrangements and C(sp³)-H Alkylation

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ACS CATALYSIS 2021年第12期11卷 7442-7449页

作者： Kang, Yi Cheng Treacy, Sean M. Rovis, Tomislav Columbia Univ Dept Chem New York NY 10027 USA

Herein we disclose an iron-catalyzed method to access skeletal rearrangement reactions akin to the Dowd-Beckwith ring expansion from unactivated C(sp(3))-H bonds. Photoinduced ligand-to-metal charge transfer at the iron center generates a chlorine radical, which abstracts electron-rich C(sp(3))-H bonds. The resulting unstable alkyl radicals can undergo rearrangement in the presence of suitable functionality. Addition to an electron deficient olefin, recombination with a photoreduced iron complex, and subsequent protodemetalation allow for redox-neutral alkylation of the resulting radical. Simple adjustments to the reaction conditions enable the selective synthesis of the directly alkylated or the rearranged-alkylated products. As a radical clock, these rearrangements also enable the measurement of rate constants of addition into various electron deficient olefins in the Giese reaction.

关键词： lmct primary C(sp(3))-H alkylation iron catalysis skeletal rearrangement Dowd-Beckwith photocatalysis

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Construction of glucose precursor carbon/TiO2 heterojunction with high ligand-to-metal charge transfer (lmct) for visible light driven CO2 reduction

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CHEMICAL ENGINEERING RESEARCH & DESIGN 2024年 201卷 353-361页

作者： Bafaqeer, Abdullah Amin, Nor Aishah Saidina Tahir, Muhammad Ummer, Aniz Chennampilly Thabit, Hammam Abdurabu Theravalappil, Rajesh Usman, Jamilu Ahmad, Nabeel King Fahd Univ Petr & Minerals Interdisciplinary Res Ctr Refining & Adv Chem Dhahran 31261 Saudi Arabia Univ Teknol Malaysia UTM Fac Chem & Energy Engn Johor Baharu 81310 Malaysia UAE Univ Chem & Petr Engn Dept POB 15551 Al Ain Yemen Univ Teknol Malaysia UTM Fac Sci Dept Phys Johor Baharu 81310 Malaysia King Fahd Univ Petr & Minerals Interdisciplinary Res Ctr Membranes & Water Secur Dhahran 31261 Saudi Arabia

Well-designed fabrication of glucose precursor carbon-doped TiO2 heterojunction with high Ligand-to-Metal Charge Transfer (lmct) for enhancing photocatalytic CO2 conversion has been examined. Photocatalysts were fabricated using a single-step thermal method and tested in a fixed-bed reactor under visible light. The 6 % glucose precursor carbon-doped over TiO2 (6 %C/TiO2) photocatalyst has demonstrated excellent activity in converting CO2 to CO and CH4 under visible light. The main product yield, CO of 739.9 mu mol g-cat(-1) was produced over 6 %C/TiO2, which is 4.4 folds the amount of CO obtained over TiO2 (168.7 mu mol g-cat(-1)). The XPS findings reveal the presence of different surface components containing C-OH, C=C, and C=O functional groups, which contribute to the formation of a ligand-metal-charge-transfer (lmct) complex between carbon and TiO2 photocatalyst. Carbon-doped TiO2 possesses a narrow energy band and the ability to effectively absorb solar light, which enables efficient transportation of electrons generated by photon excitation. The mechanism of the carbon-doped TiO2 in CO2 conversion to CO and CH4 is postulated to be consistent with the lmct complex phenomena. Therefore, carbon-doped TiO2 provides heterojunction for localization of electrons, impedes the rate at which charges recombine, and reduces the band gap energy, leading to improved photocatalytic performance when exposed to visible light.

关键词： Carbon-doped TiO2 heterojunction Glucose lmct CO2 reduction visible light

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The indenyl effect on d⁰ organotransition metal complex lmct luminescence: Synthesis, structural characterization, cyclic voltammetry, spectroscopic studies, and TD-DFT computations on (η⁵-permethylindenyl)tetrachlorotantalum(V), and comparison to (η⁵-pentamethylcyclopentadienyl)tetrachlorotantalum(V)

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POLYHEDRON 2024年 264卷

作者： Forsythe, Grant E. Smith, Gabriel J. Swenson, Dale C. Shepherd, James J. Messerle, Louis Univ Iowa Dept Chem Iowa City IA 52242 USA Michigan State Univ Dept Chem 578 S Shaw Ln E Lansing MI 48824 USA

The new organotantalum(V) chloride (eta(5)-permethylindenyl)tetrachlorotantalum, Ind*TaCl4, was prepared by addition of previously-unreported Ind*SnBu3 to TaCl5 in toluene at 70 degrees in 53 % isolated yield. The solid-state four-legged piano-stool structure, consistent with solution multinuclear NMR spectroscopies, demonstrated that tantalum is bonded to all carbons of the five-membered ring of the permethylindenyl ligand, with little deviation in the Ta-C distances. The permethylindenyl ring torsional angles for the three independent molecules in the unit cell vary from 2.46(17)degrees to 5.10(17)degrees. The cyclic voltammogram of Ind*TaCl4 in tetrahydrofuran showed one reversible reduction feature at -1.24 V [Ta(V)/Ta(IV)] and one quasi-reversible reduction feature at -1.65 V [Ta(IV)/Ta(III)] vs. Fc/Fc(+). The UV/vis lmct absorption lambda(max) at 593 nm (epsilon = 2000 M-1 cm(-1)) in toluene is remarkably red-shifted from that of the known eta(5)-pentamethylcyclopentadienyl analog, luminescent-yellow Cp*TaCl4. TD-DFT calculations were used to explain the comparative UV/vis absorption spectra.

关键词： Tantalum organometallic Permethylindenyl ligand lmct TDDFT

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Photoluminescence of europium and terbium trifluoroacetylacetonates. Participation of lmct state in processes of the energy transfer to Eu³⁺ ion

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JOURNAL OF FLUORINE CHEMISTRY 2018年 212卷 137-143页

作者： Zhuravlev, K. P. Tsaryuk, V. I. Kudryashova, V. A. Russian Acad Sci VA Kotelnikov Inst Radioengn & Elect 1 Vvedenskii Sq Fryazino 141190 Moscow Reg Russia

The effect of fluorination on spectroscopic properties of europium and terbium trifluoroacetylacetonates Ln (TFAA)(3)center dot 2H(2)O, Ln(TFAA)(3)center dot Phen and Ln(TFAA)(3)center dot Bpy in the solid state have been investigated. A threefold increase in the luminescence intensity of europium compounds at -CF3 for -CH3 substitution in the beta-diketonate ligand was obtained at 77 and 295 K. Different mechanisms of the excitation energy transfer to Ln(3+) ions in europium and terbium compounds, which result in a drop in the luminescence efficiency at elevated temperatures, have been analyzed. A key role of ligand-metal charge transfer (lmct) states in the processes of sensitization of the europium trifluoroacetylacetonates is demonstrated. Expansion of the energy gap between the lmct state and the lowest triplet state T-1 at fluorination gives rise to an increase in the excitation efficiency of the Eu3+ luminescence at 295 K. The back-transfer energy D-5(4)-T-3 in the terbium trifluoroacetylacetonates is the main reason for shortening the D-5(4) lifetime and decreasing the luminescence efficiency. The energy dissipation processes in the lanthanide TFAA adducts with heterocyclic diimines are mainly related to the beta-diketonate ligand.

关键词： Eu3+ Tb3+ beta-diketonate Trifluoroacetylacetonate Acetylacetonate Luminescence Excitation energy transfer lmct

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