[Bis(pyridine)iodine(I)] complexes offer controlled access to halonium ions under mild conditions. The reactivity of such stabilized halonium ions is primarily determined by their three-center, four-electron [N-I-N] halogen bond. We studied the importance of chelation, strain, steric hindrance and electrostatic interaction for the structure and reactivity of halogen bonded halonium ions by acquiring their N NMR coordination shifts and measuring their iodenium release rates, and interpreted the data with the support of DFT computations. A bidentate ligand stabilizes the [N-I-N] halogen bond, decreasing the halenium transfer rate. Strain weakens the bond and accordingly increases the release rate. Remote modifications in the backbone do not influence the stability as long as the effect is entirely steric. Incorporating an electron-rich moiety close by the [N-I-N] motif increases the iodenium release rate. The analysis of the iodine(I) transfer mechanism highlights the impact of secondary interactions, and may provide a handle on the induction of stereoselectivity in electrophilic halogenations.
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http://dx.doi.org/10.1002/chem.202102575 | DOI Listing |
Inorg Chem
November 2023
Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States.
X-ray structural measurements and computational analysis demonstrated the similarity of the geometries and electronic structures of the X-I···N (X = Cl, Br, I, and N) bonding in strong halogen-bonded (HaB) complexes and in the anionic or cationic halonium ions. In particular, I···N bond lengths in the solid-state associations formed by strong HaB donors (, I, IBr, ICl, and -iodosuccinimide) and acceptors (, quinuclidine or pyridines) were in the same range of 2.3 ± 0.
View Article and Find Full Text PDFChem Sci
September 2023
Key Laboratory of Colloid and Interface Chemistry of Ministry of Education and School of Chemistry and Chemical Engineering, Shandong University Jinan 250100 People's Republic of China
Axial chiral molecules are extensively used as skeletons in ligands for asymmetric catalysis and as building blocks of chiroptical materials. Designing axial chirality at the supramolecular level potentially endows a material with dynamic tunability and adaptivity. In this work, for the first time, we have reported a series of halogen-bonded dimeric complexes with axial chirality that were formed by noncovalent bonds.
View Article and Find Full Text PDFACS Nano
November 2022
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, People's Republic of China.
The [N···I···N] type halogen bond has been utilized to synthesize supramolecular architectures, while the applications in constructing helical motifs and modulating supramolecular chirality have been unexplored so far. In this work, the [N···I···N] halogen bond was introduced to drive the formation of supramolecular helical polymers via a Ag(I) coordination intermediate, showing tunable supramolecular chirality. Pyridine segments were conjugated to the asymmetric ferrocene skeleton, which show "" and "" geometry depending on the N positions.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2022
The Institute for Advanced Studies, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China.
The structural diversity and the various applications of organic frameworks have attracted much attention in recent years. Recently, halogen-bonded organic frameworks (XOFs) became a novel member of these materials, thereby facilitating the exploration of the interesting structures as well as functions. Here we present two types of [N···I···N] connected XOFs ( and ) with two tridentate ligands as building blocks.
View Article and Find Full Text PDFChemistry
August 2022
Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
The oxidation of [(Cp'''Co) (μ,η : η -E ) ] (E=As (1), P (2); Cp'''=1,2,4-tri(tert-butyl)cyclopentadienyl) with halogens or halogen sources (I , PBr , PCl ) was investigated. For the arsenic derivative, the ionic compounds [(Cp'''Co) (μ,η : η -As X)][Y] (X=I, Y=[As I ] (3 a), Y=[Co Cl I ] (n=0, 2, 4; 3 b); X=Br, Y=[Co Br ] (4); X=Cl, Y=[Co Cl ] (5)) were isolated. The oxidation of the phosphorus analogue 2 with bromine and chlorine sources yielded the ionic complexes [(Cp'''Co) (μ-PBr ) (μ-Br)][Co Br ] (6 a), [(Cp'''Co) (μ-PCl ) (μ-Cl)][Co Cl ] (6 b) and the neutral species [(Cp'''Co) (μ-PCl )(μ-PCl)(μ,η : η -P Cl ] (7), respectively.
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