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101.
Dr. Christiane Stoll Prof. Dr. Mihail Atanasov Jascha Bandemehr Prof. Dr. Frank Neese Clemens Pietzonka Prof. Dr. Florian Kraus Prof. Dr. Antti J. Karttunen Dr. Markus Seibald Assoc. Prof. Dr. Gunter Heymann Prof. Dr. Hubert Huppertz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(38):9801-9813
As a consequence of the static Jahn-Teller effect of the 5E ground state of MnIII in cubic structures with octahedral parent geometries, their octahedral coordination spheres become distorted. In the case of six fluorido ligands, [MnF6]3− anions with two longer and four shorter Mn−F bonds making elongated octahedra are usually observed. Herein, we report the synthesis of the compound K3[MnF6] through a high-temperature approach and its crystallization by a high-pressure/high-temperature route. The main structural motifs are two quasi-isolated, octahedron-like [MnF6]3− anions of quite different nature compared to that met in ideal octahedral MnIII Jahn-Teller systems. Owing to the internal electric field of Ci symmetry dominated by the next-neighbour K+ ions acting on the MnIII sites, both sites, the pseudo-rhombic (site 1) and the pseudo-tetragonally elongated (site 2) [MnF6]3− anions are present in K3[MnF6]. The compound was characterized by single-crystal and powder X-ray diffraction, and magnetometry as well as by FTIR, Raman, and ligand field spectroscopy. A theoretical interpretation of the electronic structure and molecular geometry of the two Mn sites in the lattice is given by using a vibronic coupling model with parameters adjusted from multireference ab-initio cluster calculations. 相似文献
102.
103.
Dr. Adrien Bourdolle Dr. Mustapha Allali Dr. Anthony D'Aléo Dr. Patrice L. Baldeck Dr. Kenji Kamada Prof. J. A. Gareth Williams Dr. Hubert Le Bozec Dr. Chantal Andraud Dr. Olivier Maury 《Chemphyschem》2013,14(14):3361-3367
The synthesis of tris(2‐thenoyltrifluoroacetonate)lanthanide(III) complexes featuring a diethylaminostyryl‐2,2′‐bipyridine coligand was achieved for lanthanum; the near‐infrared (NIR) emitters neodymium, erbium, and ytterbium; and the transition‐metal yttrium. The photophysical properties were thoroughly studied, and it was demonstrated that the conjugated bipyridine ligand acts as a good antenna for the sensitization of the NIR emitters. The two‐photon absorption (TPA) properties of all five complexes were investigated by using both two‐photon excited fluorescence and the Z‐scan method. We demonstrate that the nature of the rare earth ion has almost no influence on the TPA properties centered on the conjugated bipyridyl ligand. Finally, we show that YbIII is sensitized by a two‐photon antenna effect, and that NdIII is mostly sensitized by a one‐photon process involving direct excitation of forbidden f–f transitions. 相似文献
104.
Hubert Schmidbaur Graham A. Bowmaker Ulrich Deschler Cornelia Dörzbach Rudolf Herr Beatrix Milewski-mahrla 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-3):167-170
Abstract Structural data of phosphorus ylides are summarized and discussed. Conformational preferences in solution and in the solid state, as followed by NMR spectroscopy and X-ray diffraction, indicate a strong gauche effect for the lone pairs of electrons at the ylidic carbon atom. One- and two-electron oxydation of ylide carbanions is accomplished with copper(II) as the oxidant, leading to oxidative coupling or to halogenation, respectively. 相似文献
105.
Hubert Hřebabecký Milan Dejmek Martin Dračínský Michal Šála Pieter Leyssen Johan Neyts Martina Kaniaková Jan Krůšek Radim Nencka 《Tetrahedron》2012,68(4):1286-1298
Azanorbornylpurine derivatives were prepared by Mitsunobu reaction of appropriate hydroxyazanorbornane derivative with 6-chloropurine or construction of purine base at azanorbornylamines. The prepared target compounds were evaluated for antiviral activity and effect on neuronal and muscle nicotinic acetylcholine receptors. 相似文献
106.
The enantiomeric separation of various kinds of basic pharmaceuticals has been investigated in nonaqueous capillary electrophoresis (NACE) systems using an ion-pairing reagent in combination with cyclodextrins (CDs). The simultaneous addition to the methanolic background electrolyte (BGE) of (+)-S-camphorsulfonate or alkanesulfonates and an anionic beta-cyclodextrin derivative, heptakis(2,3-dimethyl-6-sulfato)-beta-cyclodextrin (HDMS-beta-CD), led to partial or complete enantioresolution in most cases. In the absence of ion-pairing reagent, the enantiomeric resolution obtained with this CD derivative was most often completely lost or strongly reduced, indicating the important role of ion-pairing in the chiral recognition mechanism in these NACE systems. The influence of the nature and concentration of the counterion and the anionic CD derivative on the enantioseparation of basic compounds was studied. Synergistic effects between these two kinds of charged additives were clearly observed. 相似文献
107.
Dr. Susanne C. Martens Dr. Ute Zschieschang Prof. Dr. Hubert Wadepohl Dr. Hagen Klauk Prof. Dr. Lutz H. Gade 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(12):3498-3509
A range of 2,9‐perfluoroalkyl‐substituted tetraazaperopyrene (TAPP) derivatives ( 1 – 5 ) was synthesised by reacting 4,9‐diamino‐3,10‐perylenequinone diimine (DPDI) with the corresponding carboxylic acid chloride or anhydride in the presence of a base. The reaction of compounds 1 – 4 with dichloroisocyanuric acid (DIC) in concentrated sulphuric acid resulted in the fourfold substitution of the tetraazaperopyrene core, yielding the 2,9‐bisperfluoroalkyl‐4,7,11,14‐tetrachloro‐1,3,8,10‐tetraazaperopyrenes 6 – 9 , respectively. The optical and electrochemical data demonstrate the drastic influence of the core substitution on the properties. All compounds are highly luminescent (fluorescence quantum yields of up to Φ=0.8). The LUMO energies of the tetrachlorinated TAPP derivatives (determined by cyclic voltammetry and computed by DFT calulations) were found to be below ?4 eV. In the course of this work the performance of TAPP derivatives in organic thin‐film transistors (TFTs) was investigated, and their n‐channel characteristics with field‐effect mobilities of up to 0.14 cm2 V?1 s?1 and an on/off current ratio of >106 were confirmed. Long‐term stabilities of 3–4 months under ambient conditions of the devices were established. Complementary inverters and ring oscillators with n‐channel TFTs based on compound 8 and p‐channel TFTs based on dinaphtho‐[2,3‐b:2′,3′‐f]thieno[3,2‐b]thiophene (DNTT) were fabricated on a glass substrate. 相似文献
108.
Caroline LapeyreFlorence Bedos-Belval Hubert Duran Michel BaltasLiliane Gorrichon 《Tetrahedron letters》2003,44(12):2445-2447
The one-pot transesterification of diethylarylvinylphosphonates with N-acetylcysteamine has been achieved using phosphonochloridates as intermediates. Reaction of phosphonodiesters with (COCl)2 gave the corresponding chlorinated compounds, which were coupled with N-acetylcysteamine in presence of Et3N. 相似文献
109.
Phenylene-1,3-dithiol is converted into a trinuclear gold complex by treatment with 1 equiv of [[(Ph(3)P)Au](3)O](+)BF(4)(-). In the product, the phenylene unit bears one gold thiolate and one di(gold)sulfonium function. These components aggregate into one-dimensional arrays through head-to-tail aurophilic contacts between the two functions. In the association process, the Au[bond]S[bond]Au angle of the sulfonium group is opened up to accommodate the incoming gold atom between its metal centers. A similar mode of aggregation is found for the triply aurated biphenylene-4,4'-dithiol obtained using the tri(gold)oxonium salt with tri(p-tolyl)phosphine ligands. Probably for steric reasons, in this oligomerization process, the gold(I) thiolate unit is attached side-on to the digold sulfonium unit with retention of the small Au[bond]S[bond]Au angle. Under similar reaction conditions, and with the same molar ratio of the components, phenylene-1,4-dithiol is converted into the bis-sulfonium salt: 1,4-[[(p-Tol)(3)PAu](2)S](2)C(6)H(4)(BF(4))(2), the dications of which also associate into chains. Along the chains, the phenylene spacers alternate with tetranuclear gold clusters which arise from intimate aggregation of pairs of gold atoms. Together with previous findings, the present results show that gold thiolate (-SAuL) and digold sulfonium functions [-S(AuL)(2)(+)] in proper orientation at an arene unit (alpha-omega) can be considered as "soldering" points which can be used for joining up the molecular units into one-dimensional arrays solely through metal-metal contacts, which appear to be operative even against Coulomb repulsion between cations. The reaction of biphenylene-4,4'-dithiol with 2 equiv of sodium methoxide and [tri(c-hexyl)phosphine]gold chloride gives only neutral digold dithiolate complex 4 which is not associated owing to the steric bulk of the tri(c-hexyl)phosphine ligands. 相似文献
110.
Sorina M. Ulmeanu Henrik Jensen Zdenek Samec Graldine Bouchard Pierre-Alain Carrupt Hubert H. Girault 《Journal of Electroanalytical Chemistry》2002,530(1-2)
Cyclic voltammetry has been used to study the coupling of ion transfer reactions at a liquid membrane. The liquids are either supported by a porous hydrophobic membrane (polyvinylidene difluoride, PVDF) when the organic solvent is non-volatile (o-nitrophenyloctylether) or are merely a free standing organic solvent layer such as 1,2-dichloroethane comprised between two hydrophilic dialysis membranes supporting the adjacent aqueous phases. The passage of current across the liquid membrane is associated with two ion transfer reactions across the two polarised liquid liquid interfaces in series. It is shown that it is possible to study the transfer of highly hydrophilic ions at one interface by limiting the mass transfer of the other ion transfer reaction at the other interface. Indeed, for systems comprising an ion M in one aqueous phase and a reference ion R partitioned between the membrane and the other aqueous phase, the observed and simulated cyclic voltammograms have a half-wave potential determined by the Gibbs energy of transfer of M transferring at one interface and by the limiting mass transfer of R at the other interface. This new methodology opens a way to measure the Gibbs energy of transfer of highly hydrophilic or hydrophobic ions, which usually limits the potential window at single liquid liquid interfaces (ITIES). 相似文献