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Complete double photoelectron spectra are presented for 18 small molecules where the location of charges in the cations and dications is relatively clearly defined. The data demonstrate the importance of a coulombic repulsion contribution to the double ionisation energies. Examination of data for a wide range of molecules leads to a new empirical rule to calculate double ionisation energies from the molecules’ single ionisation energies and maximum dimensions. Where single and double ionisation energies are known the rule allows the deduction of plausible intercharge distances. 相似文献
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Hansjürgen Mattausch Dr. Manuel C. Schaloske Constantin Hoch Chong Zheng Arndt Simon 《无机化学与普通化学杂志》2008,634(3):491-497
Rare Earth Halides Ln4X5Z. Part 1: C and/or C2 in Ln4X5Z The compounds Ln4X5Cn (Ln = La, Ce, Pr; X = Br, I and 1.0 < n < 2.0) are prepared by the reaction of LnX3, Ln metal and graphite in sealed Ta‐ampoules at temperatures 850 °C < T < 1050 °C. They crystallize in the monoclinic space group C2/m. La4I5C1.5: a = 19.849(4) Å, b = 4.1410(8) Å, c = 8.956(2) Å, β = 103.86(3)°, La4I5C2.0: a = 19.907(4) Å, b = 4.1482(8) Å, c = 8.963(2) Å, β = 104.36(3)°, Ce4Br5C1.0: a = 18.306(5) Å, b = 3.9735(6) Å, c = 8.378(2) Å, β=104.91(2)°, Ce4Br5C1.5: a = 18.996(2) Å, b = 3.9310(3) Å, c = 8.282(7) Å, β = 106.74(1)°, Pr4Br5C1.3: a = 18.467(2) Å, b = 3.911(1) Å, c = 8.258(7) Å, β = 105.25(1)° and Pr4Br5C1.5: a = 19.044(2) Å, b = 3.9368(1) Å, c = 8.254(7) Å, β = 106.48(1)°. In the crystal structure the lanthanide metals are connected to Ln6‐octahedra centered by carbon atoms or C2‐groups. The Ln6‐octahedra are condensed via opposite edges to chains and surrounded by X atoms which interconnect the chains. A part n of isolated C‐atoms is substituted by 1‐n C2‐groups. The C‐C distances range between 1.26 and 1.40Å. In the ionic formulation (Ln3+)4(X?)5(C4?)n(C2m?)1?n·e? with 0 < n < 1 and m = 2, 4, 6 (C22?, C24? C26?), there are 1 < e? < 5 electrons centered in metal‐metal bonds. 相似文献
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G. V. Khoroshenkov T. V. Petrovskaya I. L. Fedushkin M. N. Bochkarev 《无机化学与普通化学杂志》2002,628(3):699-702
The reduced lanthanide iodides of the composition LnIx (Ln = Sc, Y, La, Ce, Pr, Gd, Ho, and Er; x < 3) were obtained by the reaction of an excess of the appropriate metal with iodine at high temperatures. The diamagnetism of the Sc, Y, and La derivatives indicates the trivalent state of the metals in these products. In contrast to the diiodides of Nd(II), Dy(II), and Tm(II), the isolated solids do not dissolve in THF, DME, or liquid ammonia. Despite of their insolubility in THF, all these products readily react in this medium with phenol or alcohols to give the corresponding phenoxy‐ or alkoxylanthanide diiodides ROLnI2(THF)x (R = Ph, i‐C3H7, t‐Bu; x = 2, 3, or 5) in yields up to 55 %. Their interactions with cyclopentadiene in THF afford the complexes CpLnI2(THF)3 with yields up to 60 %. From the reaction of LaIx with 2, 2'‐bipyridine (bipy), the complex LaI2(bipy)2(THF)2 was isolated. Triphenylcarbinol, stilbene, naphthalene, and anthracene are inert towards the obtained substances. 相似文献
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Eduardo Q. Luz Diego Seckler Janylson Souza Araújo Leonardo Angst David B. Lima Elise Ane Maluf Rios Ronny R. Ribeiro Daniel S. Rampon 《Tetrahedron》2019,75(9):1258-1266
A mild and efficient iron (III)-catalyzed C3 chalcogenylation of indoles has been developed and the role of the iodide ions in this transformation was investigated. EPR experiments revealed the reduction of Fe(III) to Fe(II) under the reaction conditions, supporting the formation of molecular iodine in the system, which in effect catalyze the reaction. The scope of the chalcogenylation was broad and the synthesis of more functionalized 3-selenylindoles was explored. 相似文献
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Dr. Vinayak Botla Dr. Marco Fontana Dr. Aleksandr Voronov Prof. Raimondo Maggi Prof. Elena Motti Prof. Giovanni Maestri Prof. Nicola Della Ca' 《Angewandte Chemie (International ed. in English)》2023,62(18):e202218928
Despite the advances in the field of carbon-halogen bond formation, the straightforward catalytic access to selectively functionalized iodoaryls remains a challenge. Here, we report a one-pot synthesis of ortho-iodobiaryls from aryl iodides and bromides by palladium/norbornene catalysis. This new example of Catellani reaction features the initial cleavage of a C(sp2)−I bond, followed by the key formation of a palladacycle through ortho C−H activation, the oxidative addition of an aryl bromide and the ultimate restoration of the C(sp2)−I bond. A large variety of valuable o-iodobiaryls has been synthesized in satisfactory to good yields and their derivatization have been described too. Beyond the synthetic utility of this transformation, a DFT study provides insights on the mechanism of the key reductive elimination step, which is driven by an original transmetallation between palladium(II)-halides complexes. 相似文献
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《Journal of Coordination Chemistry》2012,65(21):3758-3766
A series of [Ln(CH3CONH2)4(H2O)4]I3 (Ln?=?rare-earth metal) complexes was completed with seven new compounds (Ln?=?Ce, Pr, Sm, Tb, Tm, Yb, Lu); two (Ln?=?Ce, Tm) were studied by X-ray diffraction. The coordination polyhedron of eight oxygen atoms is a distorted square antiprism. No tetrad effect was found for Ln–O bond lengths. The structure is stabilized by a system of intermolecular hydrogen bonds. The most striking feature of the structures is the recently predicted ionic acetamide coordination. The acetamide molecules are non-planar (the Ln–O–C–N torsion angles are 159–170°) and Ln–O–C bond angles vary in the 146.0–156.8° range. 相似文献
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[M9C4O]I8 (M = Y, Ho, Er, Lu), Reduced Rare-Earth Iodides with Waved Metal Double Layers and Two Different Interstitial Atoms [M9C4O]I8 (M = Y, Ho, Er, Lu) are examples of reduced rare-earth iodides with two different interstitial atoms. The compounds were synthesized from appropriate mixtures of MI3, M, C and M2O3 at 1 050°C in arc-welded tantalum containers. The X-ray structure analysis of a single crystal of [Y9C4O]I8 (orthorhombic, Pmmn (Nr. 59), Z = 2, a = 2 912.7(6) pm, b = 384.17(4) pm, c = 1 080.29(9) pm, R = 0.084, Rw = 0.053) exhibits octahedrally coordinated carbon in “plane” sections besides tetrahedrally coordinated oxygen in the “bend” of waved metal double layers. These double layers are stacked alternately with waved iodine double layers along [001]. 相似文献
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Hansjürgen Mattausch Eberhard Warkentin Oliver Oeckler Arndt Simon 《无机化学与普通化学杂志》2000,626(10):2117-2124
Gd10I16(C2)2 and Gd10Br15B2/Tb10Br15B2 Cluster Compounds with M10 Twin Octahedra The compound Gd10I16(C2)2 can be prepared from Gd metal, GdI3 and C at 950 °C. It crystallizes in P1 with a = 10.463(4) Å, b = 16.945(6) Å, c = 11.220(4) Å, α = 99.15(3)°, β = 92.68(3)° und γ = 88.06(3)°. Gd10Br15B2 is formed between 900 und 950 °C, Tb10Br15B2 between 900 und 930 °C from stoichiometric amounts of the rare earth metals, tribromide and boron. Both compounds crystallize in the space group P1 for Gd10Br15B2 with a = 8.984(2) Å, b = 9.816(2) Å, c = 10.552(5) Å, α = 91.14(3)°, β = 114.61(3)° and γ = 110.94(3)° and for Tb10Br15B2 with a = 8.939(4) Å, b = 9.788(3) Å, c = 10.502(2) Å, α = 91.19(3)°, β = 114.51(3)° and γ = 111.10(2)°. In the crystal structures of all three compounds the rare earth metals form edge‐shared Ln10 twin octahedra. In Gd10I16(C2)2 the Gd octahedra are centered with C2 groups (dC–C = 1.43(7) Å). In Ln10Br15B2 (Ln = Gd, Tb) the octahedra contain single boron atoms. The clusters are connected through halide atoms to chains [Ln10(Z)2X X X ]. Adjacent chains are fused threedimensionally via I I for the Gd iodide carbide and via Br Br for the bromide borides of Gd und Tb. It is interesting to see an identical pattern of connection between the chains for the reduced oxomolybdates, e. g. PbMo5O8. 相似文献