- Rhodium(III) and iridium(III) half-sandwich complexes with tertiary arsine and stibine ligands
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The syntheses of rhodium(III) and iridium(III) half-sandwich complexes containing tertiary arsine and stibine ligands of the form [Cp?M(L)Cl2] (M = Rh, Ir; L = AsEt3, AsPh3, SbPh3) are reported. These compounds represent infrequent examples of rhodium and iridium metal complexes bearing arsenic or antimony ligands. All new compounds were fully characterised using 1H and 13C NMR spectroscopy, mass spectrometry and single crystal X-ray diffraction. DFT calculations show the formation of the complexes from (Cp?MCl2)2 and EPh3 (E = P, As, Sb) to be highly exothermic, although the enthalpic driving force is decreasing in the expected sequence P > As > Sb.
- Chalmers, Brian A.,Bühl, Michael,Nejman, Phillip S.,Slawin, Alexandra M.Z.,Woollins, J. Derek,Kilian, Petr
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- Synthesis of a Homologous Series of Trialkyl Arsines (C3-C12) and Applications of Arsenic Triiodide as a Synthetic Precursor
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This work presents some modifications in the post-synthetic processing for a classical arsenic reagent: AsI3. In comparison with the widely used analog, the trichloride, arsenic triiodide presents several advantages such as low toxicity, air stability, and low volatility. It was used as a synthetic precursor in the preparation of a variety of arsenic(III) derivatives like arsines, arsenites, and thioarsenites. Besides that, AsI3 was submitted to a diversity-oriented Grignard reaction in the preparation of a homologous series of trialkyl arsines ranging from AsC3H9 to AsC12H27. The series was analyzed by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry to provide a trialkyl arsines library that can be used for the direct analysis of natural samples.
- Ligiéro, Carolina B.P.,Francisco, Marcos A.S.,Gama, Michelle S.,Carbonezi, Carlos A.,Leocadio, Isabela C.L.,de Souza, Wladmir F.,Esteves, Pierre M.
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p. 912 - 916
(2021/03/17)
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- Heteroorganic betaines 8. Synthesis and structures of silicon- and germanium-containing organoarsenic betaines R13As(1+)-CR2R3-EMe2-S(1-)- (E = Si, Ge)
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The reactions of ylides R13As=CHR2 with hexamethyl-2,4,6-trisila- and hexamethyl-2,4,6-trigermatrithiacyclohexanes afforded betaines R13As(1+)-CHR2-SiMe2-S(1-) (2) (R1 = Et; R2 = Ph (a), Me3Si (b); R1 = R2 = Ph (c)) and Et3As(1+)-CH(SiMe3)-GeMe2-S(1-) (3), respectively. Betaines 2a,b and 3 were characterized by multinuclear NMR spectroscopy. According to the X-ray diffraction data, in the crystals the As(1+)-C-E-S(1-) main chain (E = Si or Ge) of molecules 2a,b and 3 adopts a twisted cis conformation due to strong intramolecular Coulomb interactions between the anionic and cationic centers. The equilibrium geometries of isolated molecules 2a and 3, which were calculated within the framework of the density functional theory (the PBE functional, the TZ2P basis set), are in qualitative agreement with the X-ray data. In solutions, betaines 2a (in the absence of Li salts) and 2c (in the presence of LiBr) selectively decomposed according to the Corey-Chaykovsky reaction, which was accompanied by elimination of R3As and, probably, the intermediate formation of silathiirane. The subsequent transformation of the latter afforded 2,2,4,4-tetramethyl-5-phenyl-2,4-disila-1,3-dithiolane.
- Borisova, I. V.,Zemlyanskii, N. N.,Khrustalev, V. N.,Nechaev, M. S.,Kuznetsova, M. G.,Ustynyuk, Yu. A.
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p. 678 - 683
(2007/10/03)
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- Selective formation of ethanol from methanol, hydrogen and carbon monoxide
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A process for the selective formation of ethanol which comprises contacting methanol, hydrogen and carbon monoxide with a catalyst system comprising cobalt acetylacetonate, a tertiary organo Group V A compound of the periodic Table, a first promoter comprising an iodine compound and a second promoter comprising a ruthenium compound.
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