A new class of coordinately unsaturated polynuclear rhodium and iridium alkyl, benzyl, and aryl derivatives of the form [RM(1,5-cyclooctadiene)](x) have been prepared by the reaction of the organolithium reagent with the cyclooctadienemetal chlorides at -78 degrees C. The x-ray crystal structure of [mu-CH(3)Rh (1,5-cyclooctadiene)](2) is reported. The analogous iridium dimer decomposes by an initial sequence of alpha-hydrogen abstraction and then reductive elimination of hydrogen to give [mu-CH(2)Ir(1,5-cyclooctadiene)](2). Formed in high yield by the decomposition of the ethylrhodium complex was [HRh(C(8)H(11))](4), a tetrahedral cluster with face-bridging hydride ligands. Also discussed are the reactivities of the benzyl and phenyl derivatives. Unique reaction pathways for C-H bond activation and scission in this chemistry are delineated.
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http://dx.doi.org/10.1073/pnas.78.3.1318 | DOI Listing |
Nat Commun
January 2025
Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.
Fatty acid peroxygenases have emerged as promising biocatalysts for hydrocarbon biosynthesis due to their ability to perform C-C scission, producing olefins - key building blocks for sustainable materials and fuels. These enzymes operate through non-canonical and complex mechanisms that yield a bifurcated chemoselectivity between hydroxylation and decarboxylation. In this study, we elucidate structural features in P450 decarboxylases that enable the catalysis of unsaturated substrates, expanding the mechanistic pathways for decarboxylation reaction.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, People's Republic of China.
The concurrent evolution of value-added benzimidazole compounds and hydrogen within the domain of chemical synthesis is of paramount importance. The utilization of photocatalysis enhances both the efficiency and environmental benignity of the synthetic process. However, it is profoundly challenging within a photocatalytic system to simultaneously augment the number of active sites and the internal transport rate of photogenerated charge carriers.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Centre for Research in Molecular Modeling, Concordia University, Montreal, Canada.
The capture of toxic chemicals such as NH, HS, NO and SO is essential due to the tremendous threats they pose to human health and the environment. The M-MOF-74 family of metal-organic frameworks has recently gained attention as a promising category of sorbent materials for the capture of toxic chemicals; however, no clear and comprehensive relationships have been established between the capability of the M-MOF-74 to capture all target toxic chemicals and their properties such as the nature and magnetic state of the metal sites. Density-functional theory (DFT) is employed to investigate the binding energy of target molecules on M-MOF-74 with different metals including Mg, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin, 300350, P. R. China.
The practical applications of activation-unstable mesoporous metal-organic frameworks (MOFs) are often constrained by their structural instability. However, enhancing their stability could unlock valuable functionalities. Herein, we stabilized the otherwise unstable, post-activated structure of a novel mesoporous Zr(IV)-MOF, NKM-809, which constructed from a pyridine-containing amphiprotic linker (PPTB).
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Hydrazides are known to catalyze reactions of α,β-unsaturated aldehydes via transient iminium formation. The iminium intermediate displays enhanced electrophilicity, which facilitates conjugate additions and cycloadditions. We observed that a hydrazide embedded in a seven-membered ring catalyzes homoaldol condensation of a simple aldehyde in a process that displays an approximate second-order dependence on the hydrazide.
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