The coupling of electron- and proton-transfer steps provides a general concept to control the driving force of redox reactions. N splitting of a molybdenum dinitrogen complex into nitrides coupled to a reaction with Brønsted acid is reported. Remarkably, our spectroscopic, kinetic, and computational mechanistic analysis attributes N-N bond cleavage to protonation in the periphery of an amide pincer ligands rather than the {Mo-N -Mo} core. The strong effect on electronic structure and ultimately the thermochemistry and kinetic barrier of N-N bond cleavage is an unusual case of a proton-coupled metal-to-ligand charge transfer process, highlighting the use of proton-responsive ligands for nitrogen fixation.
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http://dx.doi.org/10.1002/anie.201701504 | DOI Listing |
Sci Rep
January 2025
Department of Nanotechnology, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research Education and Extension Organization (AREEO), P. O. Box: 31535-1897, Karaj, Iran.
Herein, an efficient and feasible approach was developed to oxidize low-cost agricultural waste (quinoa husk, QS) for the synthesis of carboxylated nanocellulose (CNC). The as-prepared rod-like CNCs (average diameter of 10 nm and length of 103 nm) with a high specific surface area (173 m/g) were utilized for the immobilization of a model protease enzyme (PersiProtease1) either physically or via covalent attachment. For chemical immobilization, CNCs were firstly functionalized with N, N'-dicyclohexylcarbodiimide (DCC) to provide DCNCs nanocarrier which could covalently bond to enzyme trough nucleophilic substitution reaction and formation of the amide bond between DCNCs and enzyme.
View Article and Find Full Text PDFWe report the photoluminescence and thermal stability correlation between blue emitting mononuclear gold(I)-NHC chloride complexes, N-(9-anthracenyl)-N'(n-alkyl)imidazol-2-ylidene gold(I) chloride (alkyl = n-butyl (1), n-pentyl (2), n-hexyl (3)). The solid-state study reveals a unique molecular packing due to hydrogen bonding, aurophillic interaction, and CH···π interactions in all 1-3. In addition, the π···π stacking has been found in 1.
View Article and Find Full Text PDFNat Commun
December 2024
National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan, P.R. China.
Skeleton editing for heteroarenes, especially pyrazoles, is challenging and remains scarce because these non-strained aromatics exhibit inert reactivities, making them relatively inactive for performing a dearomatization/cleavage sequence. Here, we disclose a cycloaddition-induced scaffold hopping of 5-hydroxypyrazoles to access the pyrazolopyridopyridazin-6-one skeleton through a single-operation protocol. By converting a five-membered aza-arene into a five-unit spine of a 6/6 fused-bicyclic, this work unlocks a ring-opening reactivity of the pyrazole core that involves a formal C = N bond cleavage while retaining the highly reactive N-N bond in the resulting product.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Chinese Academy of Sciences Dalian Institute of Chemical Physics, State Key Laboratory of Catalysis, CHINA.
Photocatalytic nitrogen (N2) fixation over semiconductors has always suffered from poor conversion efficiency owing to weak N2 adsorption and the difficulty of N≡N triple bond dissociation. Herein, a Co single-atom catalyst (SAC) model with a C-defect-evoked CoP4 distorted configuration was fabricated using a selective phosphidation strategy, wherein P-doping and C defects co-regulate the local electronic structure of Co sites. Comprehensive experiments and theoretical calculations revealed that the distorted CoP4 configuration caused a strong charge redistribution between the Co atoms and adjacent C atoms, minimizing their electronegativity difference.
View Article and Find Full Text PDFIUCrdata
October 2024
Département de Chimie, Université de Montréal, Complexe des sciences, 1375, Avenue Thérèse-Lavoie-Roux, Montréal, Québec H2V 0B3, Canada.
The title compound, CHBrNO, crystallizes with two similar mol-ecules in the asymmetric unit. The extended structure features dimers linked by pairs of N-H⋯O and C-H⋯O hydrogen bonds. The HNCNO moiety of the title compound shows delocalization over the N-C-N part, as evidenced by the similar C-N bond distances.
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