Article
Chemistry, Applied
Daniel Becker, Dirk Bockfeld, Matthias Tamm
Summary: In this study, two complexes were obtained by reacting the bidentate [P,N] ligand with [Ir(COD)Cl] and adding different ligands, and further reaction yielded a diiridium tetrahydride. Crystal structure analysis of the three complexes revealed that the position of the hydrogen atoms in one of the complexes could be refined freely. Since the first complex is a validated catalyst, the performance of the two complexes in deuterium labeling reactions was compared.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Physical
Jonathan De Tovar, Ashta C. Ghosh, Tom Di Santo, Mathieu Curtil, Dmitry Aldakov, Matthieu Koepf, Marcello Gennari
Summary: Immobilizing well-defined homogenous (electro)catalysts onto conductive supports is an attractive strategy for designing advanced functional materials for energy conversion. This study introduces a pyrene anchoring group on a PNP-pincer Ir-I complex and compares its CO2 reduction activity with two pyrene-free reference complexes in DMF/water mixtures. Surprisingly, all three catalysts produce HCOO- instead of CO as the main product in homogeneous conditions. After immobilization on carbon nanotubes (CNTs), the complex is still capable of driving CO2 reduction and producing HCOO- with lower overpotential in aqueous media.
Article
Chemistry, Inorganic & Nuclear
Lachlan J. Watson, Anthony F. Hill
Summary: The pro-ligands react with [RhCl(CE)(PPh3)2] to form bimetallic complexes, which undergo double C-H activation to form N-heterocyclic carbene (NHC) pincer complexes. Reduction and treatment with tritylium, ferrocenium or triphenylcyclopropenium tetrafluoroborates result in the formation of mononuclear NHC pincer complex salts. Treatment with lithium (trimethylsilyl)acetylide provides another bimetallic species, which can be obtained from [RhCl(RPm)] and LiCuCSiMe3.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Weiqin Xu, Leon Maser, Lukas Alig, Robert Langer
Summary: The coordination of a pincer ligand with a protonated carbodiphosphorane as central donor group in the rhodium(I) complex and the different reactivity of rhodium(I) and iridium(I) precursors were studied, leading to the successful synthesis of a CDP-based pincer-type complex.
Article
Chemistry, Inorganic & Nuclear
Carmen Lorenzo-Aparicio, Sonia Moreno-Blazquez, Montserrat Olivan, Miguel A. Esteruelas, Mar Gomez Gallego, Pablo Garcia-Alvarez, Javier A. Cabeza, Miguel A. Sierra
Summary: The synthesis of Pt pincer complexes derived from purine and purine nucleosides is reported. The complexes have different coordination points due to the structure of the purine skeleton and substituents on the phenyl ring. The complexes show regioselectivity and have potential applications as interstrand cross-linking models.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Jian-Gong Huang, Jiamin Jin, Qin-Zhen Yuan, Xue-Xiao Yang, Deng-Ke Cao, Chungen Liu
Summary: Upon irradiation with 415 nm light, the complex [Ir(pbt)(2)(dppn)]Cl(1) exhibits high photo-oxidation activity (87% conversion yield for 1 and 15% for the free ligand dppn) and light-controlled luminescence. Two complexes, [Ir(pbt)(2)(dppn)]Cl (1) and [Ir(pt)(2)(dppn)]Cl (2), have been synthesized to investigate the influence of cyclometalating ligands on the photo-oxidation activity and explore their photo-oxidation-induced luminescence.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Fei Fang, Jia-Xin Kang, Cong-Qiao Xu, Jiarui Chang, Jie Zhang, Shujun Li, Xuenian Chen
Summary: The influence of the pincer platform composition and substitution on the reactivity and physical properties of pincer complexes is easily explored experimentally, with subtle effects on the molecular structures and thermodynamic stability. The bond lengths and strengths of M-C-ipso, M-P, and M-X were discussed, along with thermochemical balances for different types of pincer complexes.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Jeremy E. Weber, Faraj Hasanayn, Majed Fataftah, Brandon Q. Mercado, Robert H. Crabtree, Patrick L. Holland
Summary: The study reports a new type of N-2-bridged rhenium (III) complex in which N-2 binding occurs at a higher oxidation level. Computational studies show that the weakly pi-donor pincer ligand stabilizes an open-shell electronic configuration, leading to enhanced N-2 binding in the bridged complex. The SQUID magnetometry analysis confirms a singlet ground state for this complex and offers explanations for the antiferromagnetic coupling observed.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Koichiro Masada, Shuhei Kusumoto, Kyoko Nozaki
Summary: In this study, a novel method for synthesizing metallabenzenes by replacing the phosphorus atom in an aromatic phosphinine ring with transition metal fragments was reported. Iridabenzene and rhodabenzene were successfully synthesized by triggering the replacement of the phosphorus atom with iridium and rhodium fragments, respectively. The aromaticity of the newly synthesized metallabenzenes was evaluated experimentally and theoretically.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Man-Man Xue, Jiarui Chang, Jie Zhang, Xuenian Chen
Summary: In this study, two types of platinum thiolate complexes were successfully synthesized and fully characterized. The results showed that these platinum complexes exhibited high catalytic activity in the hydrosilylation of aldehydes and ketones. Additionally, the catalytic system showed good compatibility with the subsequent hydrolysis reaction.
DALTON TRANSACTIONS
(2022)
Review
Biochemistry & Molecular Biology
Zufar N. Gafurov, Artyom O. Kantyukov, Alexey A. Kagilev, Alina A. Kagileva, Il'yas F. Sakhapov, Ilya K. Mikhailov, Dmitry G. Yakhvarov
Summary: Pincer complexes are important in organometallic chemistry, especially as homogeneous catalysts for organic transformations. Non-symmetrical phosphorus-based pincer nickel complexes have shown higher catalytic activity and have gained increasing attention in recent years. This mini-review focuses on the recent advances in the chemistry of these complexes, including ligand design, synthesis, and catalytic applications.
Article
Chemistry, Physical
Soumik Biswas, Michael J. Blessent, Benjamin M. Gordon, Tian Zhou, Santanu Malakar, David Y. Wang, Karsten Krogh-Jespersen, Alan S. Goldman
Summary: The PCP-pincer iridium complexes exhibit high regioselectivity for the transfer dehydrogenation of n-alkanes, while the closely related PCOP and POCOP complexes do not. The difference in regioselectivity is a true kinetic phenomenon, not a result of isomerization subsequent to the formation of free alpha-olefin. The different regioselectivity of the POCOPIr vs PCPIr catalysts is attributable to the different rate-determining steps of their respective catalytic cycles, which can be explained in terms of different electronic effects of O versus CH2 linker exerted through the pincer aromatic ring.
Article
Chemistry, Inorganic & Nuclear
Quinton J. Bruch, Santanu Malakar, Alan S. Goldman, Alexander J. M. Miller
Summary: This study demonstrates the electrochemical N-2 binding and splitting capabilities of a molybdenum complex, and investigates the reaction pathways and intermediates involved. Electrochemical kinetic analysis, spectroelectrochemical monitoring, and computational studies reveal two concurrent reaction pathways.
INORGANIC CHEMISTRY
(2022)
Review
Chemistry, Inorganic & Nuclear
Hugo Valdes, Juan M. German-Acacio, Gerard van Koten, David Morales-Morales
Summary: This study explores the synthesis and applications of bimetallic complexes by merging a metallocene and a (cyclopentadienyl/aryl) pincer metal complex, discussing their importance in tuning electronic properties, catalytic reactions, and chiral catalysis. Various approaches to merge metallocene and pincer-metal motifs are explored, showcasing the potential for creating diastereomerically pure derivatives through post-functionalization strategies. The authors aim to inspire further research in this field by highlighting the synthetic, physico-chemical properties, and remarkable catalytic activities of metallocene-based pincer-metal complexes.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Wolfgang Eder, Daniel Himmelbauer, Berthold Stoeger, Luis F. Veiros, Marc Pignitter, Karl Kirchner
Summary: The synthesis of various manganese and iron PCP pincer complexes via solvothermal oxidative addition was described. The reaction with sterically demanding ligands exhibited significant differences in reactivity, leading to the formation of Fe(i) complexes. X-ray structures of representative complexes were provided for analysis.
DALTON TRANSACTIONS
(2021)
Article
Multidisciplinary Sciences
Jing Yang, Lei Wang, Shaoqi Zhan, Haiyuan Zou, Hong Chen, Marten S. G. Ahlquist, Lele Duan, Licheng Sun
Summary: In this study, a ruthenium-based molecular water oxidation catalyst with negatively charged sulfonate groups was introduced, showing efficient performance under both acidic and neutral conditions. The high valent Ru intermediate Ru-V=O and seven-coordinate Ru-IV=O were found to be involved in the O-O bond formation step under acidic and neutral conditions, respectively. In both cases, the I2M pathway was dominant over the WNA pathway for O-O bond formation.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Hao Su, Marten S. G. Ahlquist
Summary: The practical applications of tetravalent metal-based MOFs have gained increased attention recently. A new eight-coordinated tetravalent metal dummy model force field has been proposed, which can accurately describe ion-induced dipole interactions and has been shown to be useful and transferable among MOFs with the same metal-core topology. The modular nature of the model allows for broad applicability to different chemical problems.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Jiajia Yi, Shaoqi Zhan, Lin Chen, Qiang Tian, Ning Wang, Jun Li, Wenhua Xu, Biaobiao Zhang, Marten S. G. Ahlquist
Summary: In this study, two facile and effective design strategies were introduced to facilitate the coupling of two catalytic units via electrostatic interactions, resulting in significantly improved catalytic performance. The intermolecular electrostatic interactions in these two systems were fully identified and found to play a key role in enhancing catalytic performance. The successful strategies demonstrated here can be utilized in designing other intercatalyst coupling systems for activation and synthesis of small molecules and organic compounds.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Applied
Biaobiao Zhang, Shaoqi Zhan, Tianqi Liu, Linqin Wang, A. Ken Inge, Lele Duan, Brian J. J. Timmer, Oleksandr Kravchenko, Fei Li, Marten S. G. Ahlquist, Licheng Sun
Summary: This study provides insights into the structure-activity relationship of water-oxidation catalysts based on Ru-bnda and related catalysts, emphasizing the importance of seven coordination for the reaction pathway and conditions necessary for O-O bond formation.
JOURNAL OF ENERGY CHEMISTRY
(2021)
Article
Chemistry, Applied
Juan Angel de Gracia Trivino, Marten S. G. Ahlquist
Summary: Intermolecular radical coupling is a main mechanism for O-O bond formation in water oxidation catalysts, with significant driving force in water solution being the hydrophobic effects. The same catalyst has also been successfully employed in generating -N2 from ammonia, but in acetonitrile where hydrophilic effects are absent. In both solvents, dimerization of the key intermediate complex occurs with similar free energy profiles, though ion-pairing is more significant in acetonitrile.
TOPICS IN CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Tianqi Liu, Ge Li, Nannan Shen, Linqin Wang, Brian J. J. Timmer, Shengyang Zhou, Biaobiao Zhang, Alexander Kravchenko, Bo Xu, Marten S. G. Ahlquist, Licheng Sun
Summary: This article investigates the structure and formation process of the Ru-III-bda complex. By designing a pocketshape Ru-based complex and conducting computational studies and single-crystal structure characterization, a Ru-III...O distance of 3.62 A for the aqua ligand was observed, and it was found to be part of a formed hydrogen-bonding network, providing clues for the formation of the Ru-III-OH2 complex.
Article
Chemistry, Multidisciplinary
Tianqi Liu, Ge Li, Nannan Shen, Linqin Wang, Brian J. J. Timmer, Alexander Kravchenko, Shengyang Zhou, Ying Gao, Yi Yang, Hao Yang, Bo Xu, Biaobiao Zhang, Marten S. G. Ahlquist, Licheng Sun
Summary: The outer coordination sphere of metalloenzyme influences its catalytic activity. By designing and synthesizing molecular catalysts with well-defined outer spheres, a significant increase in the rate of catalytic water oxidation has been achieved.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Ashleigh T. Castner, Hao Su, Erik Svensson Grape, A. Ken Inge, Ben A. Johnson, Marten S. G. Ahlquist, Sascha Ott
Summary: Electron transport and ion diffusion contribute to charge transport in metal-organic frameworks. The specific interactions between ions and linkers play a crucial role in determining the efficiency of charge transport. Understanding and controlling these interactions can lead to improved charge transport in MOFs.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Hao Yang, Fusheng Li, Shaoqi Zhan, Yawen Liu, Wenlong Li, Qijun Meng, Alexander Kravchenko, Tianqi Liu, Yi Yang, Yuan Fang, Linqin Wang, Jiaqi Guan, Istvan Furo, Marten S. G. Ahlquist, Licheng Sun
Summary: This study reports a molecularly well-defined water oxidation catalyst (WOC) with superior activity under alkaline and near-neutral conditions. By combining experimental and theoretical results, a pH-dependent O-O bond formation pathway was proposed, and the rate-determining step was identified. This research provides significant insights into the crucial role of electrolyte pH in water oxidation catalysis.
Article
Electrochemistry
Noemi Colozza, Ana Casanova, Bibiana M. Fernandez-Perez, Gaston A. Crespo, Gabriel A. Flores, Konstantinos Kavallieratos, Juan de Gracia, Marten Ahlquist, Maria Cuartero
Summary: The accurate determination of ammonium ion is important for environmental monitoring and clinical applications. This study investigates the use of tripodal tris(pyrazolyl) compounds as ionophores for ammonium ion detection. The results show that these compounds have suitable analytical performance and can suppress potassium ion interference, making them suitable for detecting ammonium ion in samples with variable contents.
Article
Chemistry, Physical
Juan Angel de Gracia Trivino, Marten S. G. Ahlquist
Summary: To enhance the stability and current density of molecular-catalyst-based electroanodes for water oxidation, immobilization of the catalysts on the electrode surface is a common strategy. This study combined three computational methods to explore the attachment and reactivity of a Ru(tda) pentamer on a graphene surface. The findings reveal that the attachment of the catalyst is completely reversed under operando conditions compared to model conditions, which is crucial for highly active molecular water oxidation catalysts immobilized on surfaces.
Article
Chemistry, Physical
Danning Zheng, Fang Liu, Tengfei Wang, Zhengkun Zhang, Hans agren, Jinglai Zhang, Marten S. G. Ahlquist, Li Wang
Summary: Dual-ionic pyrazolium salts were synthesized and found to efficiently catalyze the coupling reaction of CO2 with epichlorohydrin. The addition of water greatly improved the product yield and the formation rate of the carbonate. The mechanism of water's dual role in affecting CO2 mass transfer and triggering proton transfer for efficient CO2 conversion was proposed and confirmed by spectroscopy results.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Hemlata Agarwala, Xiaoyu Chen, Julien R. Lyonnet, Ben A. Johnson, Marten Ahlquist, Sascha Ott
Summary: This study proposes a mechanistic route for CO2-to-CO conversion using ruthenium polypyridyl catalysts. The study reveals that the ruthenium center acts as both Lewis base and Lewis acid at different stages of the catalytic cycle. By forming a 5-membered metallacyclic intermediate, the activation barrier for C-O bond cleavage is significantly decreased, leading to lower overpotentials in electrocatalytic CO2 reduction. These metallacyclic intermediates offer a new design feature for future catalyst designs.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Tengfei Wang, Danning Zheng, Beibei An, Yi Liu, Tiegang Ren, Hans Agren, Li Wang, Jinglai Zhang, Marten S. G. Ahlquist
Summary: We report a novel dual-ionic imidazolium salt catalyst that exhibits efficient catalytic activity for the cycloaddition of carbon dioxide and epoxides under environmentally friendly conditions, without the need for solvent and co-catalyst, with a yield as high as 96.1%. The catalyst can be reused multiple times with a yield maintained above 90%. Theoretical calculations and experimental measurements support a new reaction mechanism involving a CO2-philic group and an electrophilic hydrogen atom in the catalyst. Our findings suggest that incorporating CO2-philic groups is a feasible approach to develop new efficient ionic liquids.
GREEN ENERGY & ENVIRONMENT
(2022)
Article
Chemistry, Inorganic & Nuclear
Ge Li, Marten S. G. Ahlquist
Summary: In this study, density functional theory (DFT) calculations were performed to explore the properties of iron (Fe) and Ru(bda)(py)(2) catalysts, leading to the discovery of a more stable Fe(bda)(py)(2) structure. The catalytic performance of these catalysts was evaluated through theoretical comparisons, and explanations for their high potential and reactivity were provided. This study can provide insights on Fe(bda)(py)(2) as a water oxidation catalyst from a computational perspective.
DALTON TRANSACTIONS
(2022)
