Search results for "Metalation"
showing 10 items of 68 documents
Self-assembly of catalytically-active supramolecular coordination compounds within metal-organic frameworks
2019
[EN] Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal-organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of Pd-II SCCs within the confined space of a pre-formed MOF (SCCs@MOF) and its post-assembly metalation to give a Pd-II-Au-III supra molecular assembly, c…
Synthesis, characterization and electrochemistry of bismuth porphyrins: X-ray crystal structure of (OEP)Bi(SO3CF3)
2000
The metalation of several free base porphyrins by the bismuth salts Bi(NO3)3 and Bi(SO3CF3)3 in DMF or pyridine is described. The resulting stable Bi(III) porphyrin complexes are characterized by electrochemistry, 1H NMR and UV-vis spectroscopy. The structure of ( OEP ) Bi ( SO 3 CF 3) was also determined by single-crystal X-ray diffraction and shows that ( OEP ) Bi ( SO 3 CF 3) exists as a dimer which is stabilized by electrostatic interactions in which the two [(OEP)Bi]+ cations are linked via oxygen atoms of two symmetrically related [Formula: see text] anions, leading to a heptacoordinated bismuth center. Electrochemical oxidation of ( OEP ) Bi ( SO 3 CF 3) and ( T p TP ) Bi ( SO3CF3 )…
Structural and Magnetic Insights into the Trinuclear Ferrocenophane and Unexpected Hydrido Inverse Crown Products of Alkali‐Metal‐Mediated Manganatio…
2008
With the aim of introducing the diisopropylamide [NiPr(2)](-) ligand to alkali-metal-mediated manganation (AMMMn) chemistry, the temperature-dependent reactions of a 1:1:3 mixture of butylsodium, bis(trimethylsilylmethyl)manganese(II), and diisopropylamine with ferrocene in hexane/toluene have been investigated. Performed at reflux temperature, the reaction affords the surprising, ferrocene-free, hydrido product [Na(2)Mn(2) (mu-H)(2){N(iPr)(2)}(4)]2 toluene (1), the first Mn hydrido inverse crown complex. Repeating the reaction rationally, excluding ferrocene, produces 1 in an isolated crystalline yield of 62 %. At lower temperatures, the same bimetallic amide mixture leads to the manganati…
Cover Picture: Direct CH Metalation with Chromium(II) and Iron(II): Transition-Metal Host / Benzenediide Guest Magnetic Inverse-Crown Complexes (Ang…
2009
Chromation and ferration are the latest additions to the concept of alkali-metal-mediated metalation, as described by J. Klett, R. E. Mulvey, and co-workers in their Communication on page 3317 ff. While the more electropositive sodium is essential for the reaction, it is the less electropositive chromium or iron that actually performs deprotonation of benzene. This novel reactivity can be likened to a game of chess in which the queen (Na) holds the king in check, while the knight (Cr, Fe) scores checkm(etal)ate.
Unusual stability of reaction intermediates in ortho-metalation reactions of dicyclohexylphenylphosphane with dirhodium(II) tetraacetate
2013
Abstract Reaction of dirhodium(II) tetraacetate with 1 molar equivalent of dicyclohexylphenylphosphane afforded the complex [Rh 2 (μ-O 2 CCH 3 ) 3 {μ-(C 6 H 4 )PCy 2 }(CH 3 COOH) 2 ] ( 1 ) in which the phosphane ligand is coordinated to the rhodium atoms in a bridging ortho -metalated mode. As a second product, [Rh 2 (μ-O 2 CCH 3 ) 3 {μ-(C 6 H 4 )PCy 2 }(CH 3 COOH)(PhPCy 2 )] ( 2 ) was isolated from the same reaction. 2 proved to be unusually stable toward further reaction to a doubly ortho -metalated complex which has been accessible in the reaction of dirhodium(II) tetraacetate with other phosphane ligands. However, doubly ortho -metalated [Rh 2 (μ-O 2 CCH 3 ) 2 {μ-(C 6 H 4 )PCy 2 } 2 (CH…
Darstellung und struktur von (EtO)2P(O)CH2Si(Me)2CH2SnMe2Cl—ein sechsringchelat mit sesselkonformation und PO ⋯ Sn(Cl)Me2CH2-trigonaler bipyramide a…
1992
Abstract The title compound (EtO)2P(O)CH2Si(Me)2CH2SnMe2Cl (2) has been synthesized by reaction of the new functional Grignard reagent (EtO)2P(O)CH2CH2SiMe2CH2MgCl with Me3SnCl and subsequent treatment with Me2SnCl2. 2 crystallizes in the non-centrosymmetric orthorhombic space group P212121. The structure was refined to a final R-value of 0.0476. The tin atom is pentacoordinated and exhibits a nearly ideal trigonal-bipyramidal coordination (SnCl 2.518(3), Sn ⋯ O 2.371(5) A). This coordination results from a 6-membered chelate involving a chair conformation. The structure of 2 is compared with analogous compounds containing a PO ⋯ Sn- or CO ⋯ Sn-coordination in the first place and a noncy…
Dramatic selectivity differences in the association of DNA and RNA models with new ethylene- and propylene diamine derivatives and their copper compl…
2006
The affinities of polyamines consisting of ethylenediamine units equipped with either one or two terminal naphthyl-, anthryl-, or acridyl units towards PolyA.PolyU as an RNA model, and Poly(dA).Poly(dT) as a DNA model are screened by measuring the melting point changes (DeltaT(m)) of the double strands, and also partially by a fluorimetric binding assay using ethidium bromide. The larger aromatic moieties with long spacers between them allow bisintercalation; this leads to an increased preference for DNA in comparison to RNA, where ion pairing of the ammonium centers with the major RNA groove phosphates dominates. Allosteric affinity control by metalation is achieved e.g. with Cu(2+) ions, …
Synthesis, structure and reactivity of trans-UO22+ complexes of OH-containing ligands †
2000
trans-Dioxouranium dinuclear complexes of a few OH-containing ligands possessing N-, O-binding sites were synthesized and characterised. Seven of these were also structurally characterised by single crystal X-ray diffraction. All these complexes exhibit symmetric U2O2 core structures in addition to having a seven-co-ordinated environment about each uranium centre. Even when the ligand possessed more than one CH2OH group, only one such group was found to be involved both in chelation as well as in bridging. These complexes exhibited facile transmetallation reactions with vanadium and molybdenum precursors. Though their core structures are alike, the complexes differ in their lattice arrangem…
Boron–nitrogen substituted dihydroindeno[1,2-b]fluorene derivatives as acceptors in organic solar cells
2019
The electrophilic borylation of 2,5-diarylpyrazines results in the formation of boron–nitrogen doped dihydroindeno[1,2-b]fluorene which can be synthesized using standard Schlenk techniques and worked up and handled readily under atmospheric conditions. Through transmetallation via diarylzinc reagents a series of derivatives were synthesized which show broad visible to near-IR light absorption profiles that highlight the versatility of this BN substituted core for use in optoelectronic devices. The synthesis is efficient, scalable and allows for tuning through changes in substituents on the planar heterocyclic core and at boron. Exploratory evaluation in organic solar cell devices as non-ful…
Porphyrin amino acids-amide coupling, redox and photophysical properties of bis(porphyrin) amides.
2013
New trans-AB2C meso-substituted porphyrin amino acid esters with meso-substituents of tunable electron withdrawing power (B = mesityl, 4-C6H4F, 4-C6H4CF3, C6F5) were prepared as free amines 3a-3d, as N-acetylated derivatives Ac-3a-Ac-3d and corresponding zinc(II) complexes Zn-Ac-3a-Zn-Ac-3d. Several amide-linked bis(porphyrins) with a tunable electron density at each porphyrin site were obtained from the amino porphyrin precursors by condensation reactions (4a-4d) and mono- and bis(zinc(II)) complexes Zn(2)-4d and Zn(1)Zn(2)-4d were prepared. The electronic interaction between individual porphyrin units in bis(porphyrins) 4 is probed by electrochemical experiments (CV, EPR), electronic abso…