Reactions of the hydrido-butenylcarbyne complex [OsHCl2(≡CC(PPh3)=CHEt)(PPh3)2]BF4 (1) with nitriles RC≡N (R=2-cyclopropyl-2-oxopropyl, 3-amino-2-oxobutyl) lead to six-membered cyclic vinylidene complexes 3 and azavinylidene complexes 4, that is, iso-osmapyridiniums. Treatment of 1 with excess 2-formylbenzonitrile at reflux temperature in CHCl3 in the presence of air produces a fused osmapyridinium 8, which is first oxidized to the tricyclic iso-osmapyridinium derivative 7, then to iso-osmapyridinium 9, which contains a fused naphthalenone fragment. The conversion of iso-osmapyridinium 9 (with a vinylidene segment) to the iso-osmapyridinium compounds 10 and 11 (with azavinylidene segments) was achieved in the presence of a hydrogen halide, such as HCl or HI. The molecular structures of the complexes synthesized were confirmed by X-ray studies. Moreover, the aromatic stabilization energy and nucleus-independent chemical-shift values of the osmapyridiniums and the strain in the iso-osmapyridinium rings were investigated by DFT calculations.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.201504618 | DOI Listing |
Chemistry
January 2025
Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR.
The activation of various homopropargylic pyridines by cis-[Ru/Os(dppm)Cl] (dppm=1,1-bis(diphenylphosphino)methane) has previously been shown to generate a diverse array of metallacycles and metalated heterocyclic complexes. However, a minor structural modification of introducing a halide onto the pyridyl group of the alkyne substrate resulted in the formation of unprecedented Ru(II)/Os(II)-haloquinolizine complexes. These complexes display (1) κ(X,C)-haloquinolizine chelates arising from the cycloisomerization of HC≡CC(OH)(CH(6-X-2-py))(Ph) on [Ru/Os(dppm)] moieties via a vinylidene pathway, (2) five-membered Ru/Os-X-C-N-C rings (X=F, Cl, Br) ortho- and peri-fused to quinolizinium skeletons, and (3) uncommon M-X-R bonding interactions that are atypical in coordination complexes.
View Article and Find Full Text PDFACS Biomater Sci Eng
November 2024
Key Laboratory of Hunan Province for Efficient Power System and Intelligent Manufacturing, College of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China.
J Colloid Interface Sci
February 2025
Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu, Japan; College of Materials and Chemistry, China Jiliang University, Hangzhou 310018, PR China. Electronic address:
Langmuir
August 2024
College of Information Science and Engineering, Jiaxing University, Jiaxing 314001, China.
Electro-ionic soft actuators have garnered significant attention owing to their promising applications in flexible electronics, wearable devices, and soft robotics. However, achieving high actuation performance (large bending strain and fast response time) of these soft actuators under low voltage has been challenging due to issues related to ion diffusion and accumulation. In this study, an electro-ionic soft actuator is fabricated using TiCT MXene and eutectic gallium-indium (EGaIn) composite material as the bilayer electrode and methylammonium formate/1-ethyl-3-methylimidazolium tetrafluoroborate/poly(vinylidene fluoride) (MAF-EMIMBF/PVDF) as the ionic liquid-type electrolyte.
View Article and Find Full Text PDFScience
July 2024
Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, 44227 Dortmund, Germany.
Precise modification of a chemical site in a molecule at the single-atom level is one of the most elegant yet difficult transformations in chemistry. A reagent specifically designed for chemoselective introduction of monoatomic carbon is a particularly formidable challenge. Here, we report a straightforward, azide-free synthesis of a crystalline and isolable diazophosphorus ylide, PhPCN, a stable compound with a carbon atom bonded to two chemically labile groups, triphenylphosphine (PPh) and dinitrogen (N).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!