Article
Chemistry, Multidisciplinary
Nazanin Mohebi, Mohamad Zaman Kassaee
Summary: The study found that increasing the number of benzene rings can enhance the stability of NHPbs, while reducing characteristics such as nucleophilicity, electrophilicity, and chemical potential.Among them, the NHPb structure with the most benzene rings showed the greatest stability in terms of energy difference and band gap, with stronger coordination ability towards platinum metal.
STRUCTURAL CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Maria Frutos, Nasrina Parvin, Antoine Baceiredo, David Madec, Nathalie Saffon-Merceron, Vicenc Branchadell, Tsuyoshi Kato
Summary: A donor-stabilized silylene with a Ni-0-based donating ligand has been synthesized, showing a peculiar behavior due to the cooperative reactivity of Si and Ni centers. Calculations indicate that the orientation of the Ni-ligands with respect to the silylene moiety is crucial in determining the role of the Ni-fragment.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Biochemistry & Molecular Biology
Francesca Sacco, Matteo Tarchi, Giarita Ferraro, Antonello Merlino, Giorgio Facchetti, Isabella Rimoldi, Luigi Messori, Lara Massai
Summary: The study investigated the reactions of three novel platinum(II) complexes with model proteins through ESI MS analysis, revealing diverse reactivity patterns depending on the nature of the Pt complex and interacting proteins. The formation of protein-bound Pt fragments was identified, and crystal structures were used to determine the exact location of Pt binding sites, contributing to understanding the potential mechanisms of action of these innovative anticancer Pt complexes.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Chemistry, Inorganic & Nuclear
Guijie Li, Jianbing Zheng, Xiaoli Fang, Kewei Xu, Yun-Fang Yang, Jiang Wu, Linyu Cao, Jian Li, Yuanbin She
Summary: A series of N-heterocyclic carbene-based tetradentate Pd(II) complexes were designed and synthesized, which exhibited stability and high thermal decomposition temperature. The electrochemical and photophysical properties of these complexes were systematically investigated through experimental research and theoretical calculation.
Article
Chemistry, Multidisciplinary
Guijie Li, Hua Guo, Xiaoli Fang, Yun-Fang Yang, Yulu Sun, Weiwei Lou, Qisheng Zhang, Yuanbin She
Summary: A series of tetradentate Pd(II) and Pt(II) complexes containing fused 5/6/6 metallocycles with phenyl N-heteroaromatic benzo[d]imidazole (pbiz), benzo[d]oxazole (pboz), or benzo[d]thiazole (pbthz)-containing ligands were developed. Experimental and theoretical studies showed that both the central metal and benzannulated N-heteroaromatic ring significantly influence the electrochemical, photophysical, and excited-state properties of the complexes. Compared to pbiz-based complexes, those with pboz and pbthz-containing ligands exhibited significant red-shift emission spectra.
CHINESE JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
William R. Kerr, Marie A. Squire, Christopher M. Fitchett
Summary: In this study, enantiomerically pure chelating NHC-isobornylamide was synthesized and reacted with palladium and platinum salts. The results showed that the steric bulk of the chiral group played an important role in the interaction with the metal atom, and the complexes formed with acetylacetonate ligands exhibited E/Z isomerism.
JOURNAL OF ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Angela Vivancos, Delia Bautista, Pablo Gonzalez-Herrero
Summary: This study reports the synthesis, structure, photophysical properties, and electrochemistry of the first series of Pt(IV) tris-chelates bearing cyclometalated aryl-NHC ligands. The complexes exhibit significant photostability, long-lived phosphorescence, and potential application for Pt(IV) emitters with tunable properties.
INORGANIC CHEMISTRY
(2022)
Review
Chemistry, Inorganic & Nuclear
Sai Zhao, Zhibing Yang, Guizhi Jiang, Sheng Huang, Mianli Bian, Yunlong Lu, Wukun Liu
Summary: NHCs have been introduced as a new platform for the development of anticancer metal complexes, with platinum NHC complexes showing comparable activities to cisplatin and exhibiting different mechanisms of action, including the induction of biochemical hallmarks of immunogenic cell death (ICD) as a type II ICD inducer. These features make them promising candidates in the field of anticancer research.
COORDINATION CHEMISTRY REVIEWS
(2021)
Article
Chemistry, Multidisciplinary
Shaozhi Du, Hongwei Jia, Hua Rong, Haibin Song, Chunming Cui, Zhenbo Mo
Summary: The synthesis and reactivity of disilicon(0) complexes have both fundamental and application importance. In this study, a N-heterocyclic imino-substituted silylene with strong sigma-donating ability and significant steric hindrance was developed. The reaction of this silylene with [IPr -> SiCl2] and KC8 led to the formation of a silyleneligated disilicon(0) complex, which exhibited new aspects of low-valent silicon chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Silvano R. Valandro, Ru He, James D. Bullock, Hadi Arman, Kirk S. Schanze
Summary: This study investigates the femto- and picosecond excited-state dynamics of a series of N-heterocyclic carbene ligand-containing platinum complexes, revealing ultrafast singlet to triplet intersystem crossing and subsequent relaxation processes influenced by ligand torsional modes and solvent viscosity. Experimental findings show that different conformers can be photoselected by varying excitation wavelengths, while density functional theory calculations suggest the impact of geometry and steric hindrance on the ground-state energy surface.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Catriona R. Vanston, Thomas P. Nicholls, Alex C. Bissember, Michael G. Gardiner, Curtis C. Ho
Summary: This study prepared palladium complexes with a new class of cationic aNHC ligands, but found that greater conformational restrictions are necessary to achieve significant electron transfer.
INORGANIC CHEMISTRY
(2022)
Review
Chemistry, Applied
Nilanjana Mukherjee, Bhaskar Mondal, Tarak Nath Saha, Ramananda Maity
Summary: Chiral ligands are crucial in asymmetric catalysis, and electron-rich chiral N-heterocyclic carbenes (NHCs) have emerged as effective ligands for enantioselective organic transformations. Tailored ligand design has led to the development of novel transition-metal complexes, and the modular synthesis of NHCs allows for easy customization. This review article summarizes the recent advances in enantioselective catalysis using well-defined transition-metal complexes with chiral NHC donor ligands.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Review
Chemistry, Inorganic & Nuclear
Macarena Poyatos, Eduardo Peris
Summary: Janus di-N-heterocyclic carbene (NHC) ligands are a subclass of poly-NHCs that feature coordination to two transition metals in a facially opposed manner, making them useful in areas such as homogeneous catalysis, materials chemistry, and supramolecular chemistry. This review aims to cover the most relevant advances in the use of Janus-di-NHCs over the last 15 years, classified by their specific structural features.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Shahar Dery, Peter Bellotti, Tzipora Ben-Tzvi, Matthias Freitag, Tehila Shahar, Albano Cossaro, Alberto Verdini, Luca Floreano, Frank Glorius, Elad Gross
Summary: Adsorption of chiral molecules on heterogeneous catalysts is a simple approach for inducing an asymmetric environment to enable enantioselective reactivity. However, successful practical utilization of chiral induction is complex and understanding the factors behind it is crucial for the mechanism of chirality transfer. Adsorption geometry of OH-functionalized N-heterocyclic carbenes plays a key role in influencing enantioselectivity in a-arylation reactions on Pd nanoparticles.
Article
Chemistry, Inorganic & Nuclear
Debsouri Kundu, Natalia del Rio, Marie Cordier, Nicolas Vanthuyne, Emma V. Puttock, Stefan C. J. Meskers, J. A. Gareth Williams, Monika Srebro-Hooper, Jeanne Crassous
Summary: The preparation, structural and spectroscopic characterization of the first enantiopure cycloplatinated complexes with a bidentate, helicenic N-heterocyclic carbene and a diketonate ancillary ligand were investigated through experimental and computational studies. These complexes exhibit long-lived circularly polarized phosphorescence, with dissymmetry factor g(lum) values >= 10(-3) in solution, doped films at room temperature, and around 10(-2) in a frozen glass at 77 K.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Sebastian Termuehlen, Patrick D. Dutschke, Alexander Hepp, F. Ekkehardt Hahn
Summary: The electronic properties of two indole-derived CAAC ligands were investigated using DFT calculations, showing similarities to classical CAACs but with smaller % V-bur due to smaller N-substituents. An Se adduct of one of the ligands was prepared and characterized, revealing pi-acceptor properties similar to classical CAACs.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jan Keuter, Alexander Hepp, Felicitas Lips
Summary: The in-situ generated amido-substituted disilynes obtained from the reductive dehalogenation of tribromosilanes were trapped with ethylene to yield cycloaddition products. DFT calculations revealed differences in the triple bond character between the two transient disilynes. Furthermore, the reductive debromination of a bromo-substituted silacyclopentene in the presence of an alkene resulted in the formation of a cyclotrisilene side product.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jan Keuter, Maria Dimitrova, Oliver Janka, Alexander Hepp, Raphael J. F. Berger, Felicitas Lips
Summary: The investigation reveals that the anionic siliconoid cluster [Si-7{N(SiMe3)Dipp}(3)](-) has two distinct strong diatropic vortices, resulting in a strongly shielded apical silicon atom.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Thomas M. Kirse, Joschua Lueke, Ivan Maisuls, Alexander Hepp, Cristian A. Strassert
Summary: In this work, coordination compounds featuring caffeine-based carbene co-ligands and tridentate dianionic pincer luminophores were studied. The influence of different substituents on the photophysical properties was assessed. The results showed that the four luminophores performed similarly and cyclometallation improved the synthetic efficiency but was not essential for achieving high photoluminescence quantum yields. In summary, coordination chemical concepts based on natural products can lead to stable phosphorescent species with interesting excited-state properties.
PHOTOCHEMISTRY AND PHOTOBIOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Ye Lu, Patrick D. Dutschke, Jenny Kinas, Alexander Hepp, Guo-Xin Jin, F. Ekkehardt Hahn
Summary: Here, we report the synthesis and characterization of a series of organometallic Borromean rings (BRs) and [2]catenanes prepared from benzobiscarbene ligands. The formation and stability of these interlocked species are strongly influenced by solvophobic effects. The stability of BRs can be enhanced by using precursors with longer alkyl substituents, while the proportion of [2]catenanes in solution can be increased by lengthening the N-alkyl substitutes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Tobias Theiss, Stefan Buss, Ivan Maisuls, Rafael Lopez-Arteaga, Dana Bruenink, Jutta Koesters, Alexander Hepp, Nikos L. Doltsinis, Emily A. Weiss, Cristian A. Strassert
Summary: The synthesis, structure, and photophysical properties of two isoleptic bis-cyclometalated Pt(II) and Pd(II) complexes, [PtL] and [PdL], were reported. NMR spectroscopy and X-ray diffraction analysis confirmed the isostructural nature and intermolecular interactions of the complexes. Both complexes exhibited ligand-controlled aggregation, with the photophysical properties tunable through molecular design. The introduction of fluorine atoms and methoxy groups led to metal-metal interactions, resulting in luminescence from metal-perturbed ligand-centered or metal-metal-to-ligand charge-transfer triplet states.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Inorganic & Nuclear
Sebastian Termuehlen, Patrick D. Dutschke, Alexander Hepp, F. Ekkehardt Hahn
Summary: The 2-Chloro-3,3-dimethyl-N-ethylindoleninium tetrafluoroborate was reacted with three different carbon-ylmetalates to obtain neutral carbonyl complexes with a benzannu-lated cyclic (alkyl)(amino)carbene ligand. The chromium complex was then used to transfer the CAAC ligand to gold, resulting in a new gold complex. The quantitative information regarding the sigma-donor properties of the CAAC ligand was determined from the 13C NMR spectrum of this gold complex.
Article
Chemistry, Multidisciplinary
Stefan Buss, Maria Victoria Cappellari, Alexander Hepp, Jutta Koesters, Cristian A. Strassert
Summary: This research focuses on the synthesis and characterization of Pt(II) complexes that contain different tri- and tetradentate luminophores serving as C^N*N- and C^N*N^C chelators. The study explores different substitution patterns to enhance their processability and examines how structural variations affect their excited state properties. The photophysical properties of these complexes are analyzed using steady-state and time-resolved photoluminescence spectroscopy, including absorption and emission spectra, photoluminescence efficiencies, and excited state lifetimes at different temperatures. The findings demonstrate that the decoration of the bridging unit on tridentate luminophores has minimal impact on excited state properties, while double cyclometallation related to tetradentate chelators prolongs excited state lifetime and enhances photoluminescence quantum yield.
CHEMISTRY-SWITZERLAND
(2023)
Article
Multidisciplinary Sciences
Jingjing Zhang, Christian Mueck-Lichtenfeld, Armido Studer
Summary: Chemical activation of water is a hot topic in energy research and enables the conversion of this abundant resource into valuable compounds. In this study, we demonstrate the activation of water using a photocatalytic phosphine-mediated radical process, which involves sequential heterolytic and homolytic cleavage of O-H bonds. The resulting PR3-OH radical intermediate can react with various closed-shell p systems, leading to transfer hydrogenation of the p system and incorporation of hydrogen atoms from water into the product. Experimental and theoretical studies support the importance of the hydrogen atom transfer step in this radical hydrogenation process.
Article
Chemistry, Multidisciplinary
Zi-Xuan Wang, Keith Livingstone, Carla Huempel, Constantin G. Daniliuc, Christian Mueck-Lichtenfeld, Ryan Gilmour
Summary: Fluorinated small molecules are commonly used in the field of functional small molecules. Researchers have developed creative approaches to access these important materials by utilizing iodine(I)/iodine(III) catalysis to convert abundant alkene substrates into high-value (di)fluorinated products. They also discovered that enynes can be used as proxies for styrenes, simplifying the process and enabling the generation of highly versatile homopropargylic difluorides.
Review
Chemistry, Multidisciplinary
Qiu Sun, Christian Mueck-Lichtenfeld, Gerald Kehr, Gerhard Erker
Summary: The study of 3D architectures at a molecular scale, specifically molecular pyramids with all-carbon frameworks and various geometries, has been a fascinating subject for chemists. While some substituted forms of tetrahedranes and all-carbon [4]-[5]pyramidanes have been experimentally generated and explored, the hypothetical unsubstituted parent [3]-[6]pyramidanes have primarily been studied computationally. However, the replacement of carbon vertices with isolobal main group element fragments has resulted in stable hetero[m]pyramidanes that have been successfully synthesized and characterized.
NATURE REVIEWS CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Lukas Schifferer, Leon Hoppmann, Robin Groeters, Christian Mueck-Lichtenfeld, Constantin G. Daniliuc, Olga Garcia Mancheno
Summary: A solvent-dependent, divergent synthesis of highly functionalized N,S-heterocycles, containing thiazoline and isoquinuclidine or tetrahydroisoquinoline scaffolds, has been reported. This synthesis involves cyclization reactions of isoquinolinium 1,4-zwitterionic thiolates and shows robustness and applicability as demonstrated by efficient upscaling of the reaction and derivatization of the resulting products.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Sebastian Termuehlen, Patrick D. Dutschke, Alexander Hepp, F. Ekkehardt Hahn
Summary: In this study, it was found that 2-Chloro-3,3-dimethyl-N-ethylindoleninium tetrafluoroborate underwent oxidative addition with three carbon-ylmetalates, resulting in the formation of neutral carbonyl complexes with a benzannulated cyclic (alkyl)(amino)carbene (CAAC) ligand. The chromium complex was further utilized for the transmetalation of the CAAC ligand to gold(I), and the electronic properties of the CAAC ligand in the resulting gold complex were quantitatively characterized.
Article
Biochemistry & Molecular Biology
Stefan Buss, Leon Geerkens, Maria Victoria Cappellari, Alexander Hepp, Jutta Koesters, Cristian A. Strassert
Summary: This study investigates the impact of auxiliary ligands on the photophysical properties of Pt(II) complexes and demonstrates that the properties of the auxiliary ligands have some influence on the photoluminescence characteristics, but cannot significantly improve the photoluminescence quantum yield at room temperature.
Article
Biochemistry & Molecular Biology
Matias E. Gutierrez Suburu, Meik Blanke, Alexander Hepp, Oliver Maus, Dominik Schwab, Nikos L. Doltsinis, Wolfgang G. Zeier, Michael Giese, Jens Voskuhl, Cristian A. Strassert
Summary: A series of Pt(II) complexes with different regioisomers were synthesized and characterized. The position of the regioisomer affects the emission color and deactivation rate constants. Some of the complexes also exhibit thermochromic properties due to the metal-metal interactions and alkyl groups.
