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《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(1):195-203
Seven discrete sugar‐pendant diamines were complexed to the {M(CO)3}+ (99mTc/Re) core: 1,3‐diamino‐2‐propyl β‐D ‐glucopyranoside ( L 1 ), 1,3‐diamino‐2‐propyl β‐D ‐xylopyranoside ( L 2 ), 1,3‐diamino‐2‐propyl α‐D ‐mannopyranoside ( L 3 ), 1,3‐diamino‐2‐propyl α‐D ‐galactopyranoside ( L 4 ), 1,3‐diamino‐2‐propyl β‐D ‐galactopyranoside ( L 5 ), 1,3‐diamino‐2‐propyl β‐(α‐D ‐glucopyranosyl‐(1,4)‐D ‐glucopyranoside) ( L 6 ), and bis(aminomethyl)bis[(β‐D ‐glucopyranosyloxy)methyl]methane ( L 7 ). The Re complexes [Re( L 1 – L 7 )(Br)(CO)3] were characterized by 1H and 13C 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re( L 2 )(CO)3Br] and [Re( L 3 )(CO)3Br], were characterized in the solid state by X‐ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H2O established that the complexes exist as [Re( L 1 – L 7 )(H2O)(CO)3]Br in aqueous conditions. Radiolabelling of L 1 – L 7 with [99mTc(H2O)3(CO)3]+ afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period. 相似文献
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Metal–Metal Single Bonds with the Magnetic Anisotropy of Quadruple Bonds: A Systematic Series of Heterobimetallic Bismuth(II)–Rhodium(II) Formamidinate Complexes
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Dr. Travis L. Sunderland Dr. John F. Berry 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(51):18564-18571
The first set of five heterobimetallic MM′(form)4 (form=formamidinate) complexes containing a BiRh core has been successfully synthesized. The Bi?Rh bond lengths lie between 2.5196(6) and 2.572(2) Å, consistent with Bi?Rh single bonds. All complexes have rich electrochemistry, with the [BiRh]4+/5+ redox couples spanning approximately 700 mV and showing a strong correlation to remote ligand substitution. Visible spectroscopy showed two features for complexes 1 – 5 at approximately 459 and 551 nm, unique to BiRh paddlewheel complexes that are attributed to LMCT bands into the Bi?Rh σ* orbital. The large spin–orbit coupling (SOC) of Bi creates a massive Bi?Rh magnetic anisotropy, Δχ, approximately ?4800×10?36 m3molecule?1, which is the largest value reported for any single bond to date. 相似文献
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We study the excited states of two iridium(III) complexes with potential applications in organic light‐emitting diodes: fac‐tris(2‐phenylpyridyl)iridium(III) [Ir(ppy)3] and fac‐tris(1‐methyl‐5‐phenyl‐3‐n‐propyl‐[1,2,4]triazolyl)iridium(III) [Ir(ptz)3]. Herein we report calculations of the excited states of these complexes from time‐dependent density functional theory (TDDFT) with the zeroth‐order regular approximation (ZORA). We show that results from the one‐component formulation of ZORA, with spin–orbit coupling included perturbatively, accurately reproduce both the results of the two‐component calculations and previously published experimental absorption spectra of the complexes. We are able to trace the effects of both scalar relativistic correction and spin–orbit coupling on the low‐energy excitations and radiative lifetimes of these complexes. In particular, we show that there is an indirect relativistic stabilisation of the metal‐to‐ligand charge transfer (MLCT) states. This is important because it means that indirect relativistic effects increase the degree to which SOC can hybridise singlet and triplet states and hence plays an important role in determining the optical properties of these complexes. We find that these two compounds are remarkably similar in these respects, despite Ir(ppy)3 and Ir(ptz)3 emitting green and blue light respectively. However, we predict that these two complexes will show marked differences in their magnetic circular dichroism (MCD) spectra. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(24):7070-7073
We report a C−F reductive elimination from a characterized first‐row aryl metal fluoride complex. Reductive elimination from the presented nickel(III) complexes is faster than C−F bond formation from any other characterized aryl metal fluoride complex. 相似文献
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Yoshihiro Shimoyama Dr. Tomoya Ishizuka Dr. Hiroaki Kotani Prof. Dr. Yoshihito Shiota Prof. Dr. Kazunari Yoshizawa Dr. Kaoru Mieda Prof. Dr. Takashi Ogura Dr. Toshihiro Okajima Prof. Dr. Shunsuke Nozawa Prof. Dr. Takahiko Kojima 《Angewandte Chemie (International ed. in English)》2016,55(45):14041-14045
Proton‐coupled electron‐transfer oxidation of a RuII?OH2 complex, having an N‐heterocyclic carbene ligand, gives a RuIII?O. species, which has an electronically equivalent structure of the RuIV=O species, in an acidic aqueous solution. The RuIII?O. complex was characterized by spectroscopic methods and DFT calculations. The oxidation state of the Ru center was shown to be close to +3; the Ru?O bond showed a lower‐energy Raman scattering at 732 cm?1 and the Ru?O bond length was estimated to be 1.77(1) Å. The RuIII?O. complex exhibits high reactivity in substrate oxidation under catalytic conditions; particularly, benzaldehyde and the derivatives are oxidized to the corresponding benzoic acid through C?H abstraction from the formyl group by the RuIII?O. complex bearing a strong radical character as the active species. 相似文献
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Franz von Nussbaum Peter Spiteller Matthias Rüth Wolfgang Steglich Gerhard Wanner Brandy Gamblin Lorenzo Stievano Friedrich E. Wagner 《Angewandte Chemie (International ed. in English)》1998,37(23):3292-3295
An iron ink has been detected as the pigment of the beautiful dark violet mushroom Cortinarius violaceus. The amino acid (R)-β-dopa ( 1 ) is the ligand of the 1:2 Feiii –catechol complex. 相似文献
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S. A. Adonin M. N. Sokolov V. P. Fedin 《Russian Journal of Inorganic Chemistry》2017,62(14):1789-1796
Recent advances in studies of bismuth(III) halide complexes (HBs) are reviewed concisely. New structural types of HBs and some of their physical properties that show the greatest promise for application and attract the greatest attention of researchers are discussed. 相似文献
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The polymerization of methyl methacrylate and acrylonitrile can be initiated by the chitosan-copper(II) complex and its monomeric form, glucosamine-copper(II) complex, in the presence of carbon tetrachloride. The chitosan complex system was found to be more active for initiating the polymerization of methyl methacrylate than acrylonitrile at neutral pH. On the other hand, the glucosamine complex system showed no activity at neutral pH region, but had high activity at higher pH, because of the reducing endgroup of the glucosamine. Formation of the copper(II) complexes was studied by pH titration and visible spectroscopy. The relationship between complex formation and the activity for initiating the polymerization is discussed. 相似文献
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Tristram Chivers Cees Lensink John F. Richardson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):189-192
Abstract The preparation and X-ray structure (M=Mo) of complexes of the type M(CO)5(Ph2PNSO) (M=Cr,Mo) are described. These complexes are used in the synthesis of homo- and hetero-dinuclear complexes of Ph2PNSNPPh2. A 31P DNMR study of these dinuclear complexes indicates a cis, trans → trans, cis isomerization in solution. The preparation and X-ray structure (M=Cr) of the mononuclear complexes, cis-M(CO)4(P(Ph)2NSN(Ph)2P), (M=Cr,Mo) are also described. 相似文献
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A carbohydrate–anion recognition system in nonpolar solvents is reported, in which complexes form at the B‐faces of β‐D ‐pyranosides with H1‐, H3‐, and H5‐cis patterns similar to carbohydrate–π interactions. The complexation effect was evaluated for a range of carbohydrate structures; it resulted in either 1:1 carbohydrate–anion complexes, or 1:2 complex formation depending on the protection pattern of the carbohydrate. The interaction was also evaluated with different anions and solvents. In both cases it resulted in significant binding differences. The results indicate that complexation originates from van der Waals interactions or weak CH ??? A? hydrogen bonds between the binding partners and is related to electron‐withdrawing groups of the carbohydrates as well as increased hydrogen‐bond‐accepting capability of the anions. 相似文献
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Marcus Schulze Dr. Andreas Steffen Prof. Dr. Frank Würthner 《Angewandte Chemie (International ed. in English)》2015,54(5):1570-1573
The phosphorescence emission of perylene bisimide derivatives has been rarely reported. Two novel ruthenium(II) and iridium(III) complexes of an azabenz‐annulated perylene bisimide (ab‐PBI), [Ru(bpy)2(ab‐PBI)][PF6]2 1 and [Cp*Ir(ab‐PBI)Cl]PF6 2 are now presented that both show NIR phosphorescence between 750–1000 nm in solution at room temperature. For an NIR emitter, the ruthenium complex 1 displays an unusually high quantum yield (Φp) of 11 % with a lifetime (τp) of 4.2 μs, while iridium complex 2 exhibits Φp<1 % and τp=33 μs. 1 and 2 are the first PBI‐metal complexes in which the spin–orbit coupling is strong enough to facilitate not only the Sn→Tn intersystem crossing of the PBI dye, but also the radiative T1→S0 transition, that is, phosphorescence. 相似文献
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Josef T. Boronski Laurence R. Doyle John A. Seed Ashley J. Wooles Stephen T. Liddle 《Angewandte Chemie (International ed. in English)》2020,59(1):295-299
Despite there being numerous examples of f‐element compounds supported by cyclopentadienyl, arene, cycloheptatrienyl, and cyclooctatetraenyl ligands (C5–8), cyclobutadienyl (C4) complexes remain exceedingly rare. Here, we report that reaction of [Li2{C4(SiMe3)4}(THF)2] ( 1 ) with [U(BH4)3(THF)2] ( 2 ) gives the pianostool complex [U{C4(SiMe3)4}(BH4)3][Li(THF)4] ( 3 ), where use of a borohydride and preformed C4‐unit circumvents difficulties in product isolation and closing a C4‐ring at uranium. Complex 3 is an unprecedented example of an f‐element half‐sandwich cyclobutadienyl complex, and it is only the second example of an actinide‐cyclobutadienyl complex, the other being an inverse‐sandwich. The U?C distances are short (av. 2.513 Å), reflecting the formal 2? charge of the C4‐unit, and the SiMe3 groups are displaced from the C4‐plane, which we propose maximises U?C4 orbital overlap. DFT calculations identify two quasi‐degenerate U?C4 π‐bonds utilising the ψ2 and ψ3 molecular orbitals of the C4‐unit, but the potential δ‐bond using the ψ4 orbital is vacant. 相似文献
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AbstractMetal cations observed with tetrachloroaluminate anion provide insights into the structure and stability of reactive cations. Addition of tris(3,5-dimethylpyrazolyl)borate anion (TpMe2) to [BiCl2][AlCl4] traps a bismuth(III) dication, [TpMe2Bi]2+, possessing a highly electrophilic bismuth center with short coordinate Bi―N bonds. [TpMe2Bi]2+ has weak interactions with the chlorides of [Bi3Cl13]∞. Strong affinity of [TpMe2Bi]2+ with the triflate (OTf) observed in [TpMe2Bi(OTf)3]- demonstrates the high electrophilicity at bismuth. 相似文献