Fullerene Bromides C₇₀Br_<i>n</i> (<i>n</i> = 8, 10, 14) Synthesis and Identification and Phase Equilibria in the C₇₀Br_<i>n</i> (<i>n</i> = 8, 10, 14)/Solvent Systems

The paper presents experimental data on synthesis and identification (IR, UV spectra, TG, DTG, DTA analysis) of the fullerene bromides C₇₀Br_<i>n</i> (<i>n</i> = 8, 10, 14). The data on the temperature dependence of solubility in aromatic solvents (1,2-dichlorobenzene, benzene, 1-methylbenzene, 1,2-dimethylbenzene) in the temperature range (293 to 353 )K are presented and characterized; compositions of equilibrium solid phases in binary C₇₀Br_<i>n</i> (<i>n</i> = 8, 10, 14) + aromatic solvents system are determined

Fullerenol‑<i>d</i> Solubility in Fullerenol‑<i>d</i>–Inorganic Salt–Water Ternary Systems at 25 °C

In this work, solubility in ternary systems fullerenol-<i>d</i>–NaCl–H₂O, fullerenol-<i>d</i>–Pr (NO₃) ₃–H₂O, fullerenol-<i>d</i>–YCl₃–H₂O, fullerenol-<i>d</i>–uranyl sulfate–water, and fullerenol-<i>d</i>–CuCl₂–water at 25 °C by the method of isothermal saturation in ampules was studied; a description of the results is presented

Selective Nucleophilic Oxygenation of Palladium-Bound Isocyanide Ligands: Route to Imine Complexes That Serve as Efficient Catalysts for Copper-/Phosphine-Free Sonogashira Reactions

Metal-mediated reactions between <i>cis-</i>[PdCl₂(CNR)₂] (R = Xy (<b>1</b>), Cy (<b>2</b>), <i>t</i>Bu (<b>3</b>), C₆H₃(Cl-2)­Me-6 (<b>4</b>)) and the <i>keto</i>nitrones Ph₂CN­(O)­C₆H₄R′ (R′ = Me (<b>5</b>), Cl (<b>6</b>)) proceed in a 1:1 molar ratio as selective nucleophilic oxygenations and provide the imine–isocyanide complexes [PdCl₂{N­(C₆H₄R′)CPh₂}­(CNR)] (<b>7</b>–<b>14</b>: R′ = Me, R = Xy (<b>7</b>), Cy (<b>8</b>), <i>t</i>Bu (<b>9</b>), C₆H₃(Cl-2)­Me-6 (<b>10</b>); R′ = Cl, R = Xy (<b>11</b>), Cy (<b>12</b>), <i>t</i>Bu (<b>13</b>), C₆H₃(Cl-2)­Me-6 (<b>14</b>)) in excellent yields (90–94%), while the reaction of the <i>cis-</i>[PdCl₂(CNR)₂] complexes with <i>aldo</i>nitrones proceeds as 1,3-dipolar cycloaddition, giving carbene adducts which then convert to the imine complexes. Theoretical calculations at the DFT level indicate that, in the case of aldonitrones, formation of the imine complexes occurs preferably via a cycloaddition/splitting pathway, including the generation of a cycloadduct, while, in the case of ketonitrones, both the cycloaddition/splitting route and the direct oxygen atom transfer pathway are equally plausible from a kinetic viewpoint. Complexes <b>7</b>–<b>14</b> were characterized by elemental analyses (C, H, N), by high-resolution ESI⁺-MS, IR, and ¹H and ¹³C­{¹H} NMR spectroscopy, and also by X-ray diffraction (for <b>8</b>). The catalytic activity study conducted for <b>7</b>–<b>14</b>, taken as the catalysts in the Cu-/phosphine-free Sonogashira reaction, was evaluated for a typical model system comprising 4-methoxyiodobenzene and phenylacetylene and affording 1-methoxy-4-(phenylethynyl)­benzene. The obtained data indicate that <b>7</b>–<b>14</b> exhibit a high catalytic activity (yields up to 95%, TONs up to 15000), and these catalysts are among the best studied so far

Regio- and Stereoselective 1,3-Dipolar Cycloaddition of Cyclic Azomethine Imines to Platinum(IV)-Bound Nitriles Giving Δ²‑1,2,4-Triazoline Species

The complex <i>trans-</i>[PtCl₄(EtCN)₂] (<b>14</b>) reacts smoothly at 25 °C with the stable cyclic azomethine imines R¹CHN^<i>a</i>NC­(O)­CH­(NHC­(O)­C₆H₄R³)­C^<i>b</i>H­(C₆H₄R²)^{(<i>a</i>−<i>b</i>)} [R¹/R²/R³ = <i>p-</i>Me/H/H (<b>8</b>); <i>p-</i>Me/<i>p-</i>Me/H (<b>9</b>); <i>p-</i>Me/<i>p-</i>MeO/H (<b>10</b>); <i>p-</i>Me/<i>p-</i>Cl/<i>p-</i>Cl (<b>11</b>); <i>p-</i>MeO/<i>p-</i>Me/H (<b>12</b>); <i>p-</i>MeO/<i>p-</i>Cl/<i>m-</i>Me (<b>13</b>)], and the reaction proceeds as stereoselective 1,3-dipolar cycloaddition to one of the EtCN ligands accomplishing the <i>mono</i>cycloadducts <i>trans-</i>[PtCl₄(EtCN)­{N^<i>a</i>C­(Et)­<i>N</i>^<i>b</i>C­(O)­CH­(NHC­(O)­C₆H₄R³)­CH­(C₆H₄R²)­<i>N</i>^<i>c</i>C^<i>d</i>HR¹}])^{(<i>a–d;b–c</i>)} [R¹/R²/R³ = <i>p-</i>Me/H/H (<b>15</b>); <i>p-</i>Me/<i>p-</i>Me/H (<b>16</b>); <i>p-</i>Me/<i>p-</i>MeO/H (<b>17</b>); <i>p-</i>Me/<i>p-</i>Cl/<i>p-</i>Cl (<b>18</b>); <i>p-</i>MeO/<i>p-</i>Me/H (<b>19</b>); <i>p-</i>MeO/<i>p-</i>Cl/<i>m-</i>Me (<b>20</b>)]. Inspection of the obtained and literature data indicate that the cycloaddition of the azomethine imines to the C≡N bonds of HCN and of Pt^IV-bound EtCN has different regioselectivity leading to Δ²-1,2,3-triazolines and Δ²-1,2,4-triazolines, respectively. Platinum­(II) species <i>trans-</i>[PtCl₂(EtCN)­{N^<i>a</i>C­(Et)­<i>N</i>^<i>b</i>C­(O)­CH­(NHC­(O)­C₆H₄R³)­CH­(C₆H₄R²)­<i>N</i>^<i>c</i>C^<i>d</i>HR¹}]^{(<i>a–d;b–c</i>)} [R¹/R²/R³ = <i>p-</i>Me/H/H (<b>21</b>); <i>p-</i>Me/<i>p-</i>Me/H (<b>22</b>); <i>p-</i>Me/<i>p-</i>MeO/H (<b>23</b>); <i>p-</i>Me/<i>p-</i>Cl/<i>p-</i>Cl (<b>24</b>); <i>p-</i>MeO/<i>p-</i>Me/H (<b>25</b>); <i>p-</i>MeO/<i>p-</i>Cl/<i>m-</i>Me (<b>26</b>)] were obtained by a one-pot procedure from <b>14</b> and <b>8</b>–<b>13</b> followed by addition of the phosphorus ylide Ph₃PCHCO₂Me. Δ²-1,2,4-Triazolines N^<i>a</i>C­(Et)<i>­N</i>^<i>b</i>C­(O)­CH­(NHC­(O)­C₆H₄R³)­CH­(C₆H₄R²)­<i>N</i>^<i>c</i>C^<i>d</i>HR^{1(<i>a–d;b–c</i>)} [R¹/R²/R³ = <i>p-</i>Me/H/H (<b>27</b>); <i>p-</i>Me/<i>p-</i>Me/H (<b>28</b>); <i>p-</i>Me/<i>p-</i>MeO/H (<b>29</b>); <i>p-</i>Me/<i>p-</i>Cl/<i>p-</i>Cl (<b>30</b>); <i>p-</i>MeO/<i>p-</i>Me/H (<b>31</b>); <i>p-</i>MeO/<i>p-</i>Cl/<i>m-</i>Me (<b>32</b>)] were liberated from <b>21</b>–<b>26</b> by the treatment with bis­(diphenylphosphyno)­ethane (dppe). Platinum­(II) complexes <b>21</b>–<b>26</b> were characterized by elemental analyses (C, H, N), high-resolution electrospray ionization mass spectrometry (ESI-MS), and IR and ¹H and ¹³C­{¹H} NMR spectroscopies and single crystal X-ray diffraction in the solid state for <b>25</b>·CH₃OH, <b>26</b>·(CHCl₃)_0.84. The structure of <b>26</b> was also determined by COSY-90 and NOESY NMR methods in solution. Quantitative evaluation of several pairs of interproton distances obtained by NMR and X-ray diffraction agrees well with each other and with those obtained by the MM+ calculation method. Platinum­(IV) complexes <b>15</b>–<b>20</b> were characterized by ¹H NMR spectroscopy. Metal-free 6,7-dihydropyrazolo­[1,2-<i>a</i>]­[1,2,4]­triazoles (<b>27</b>–<b>32</b>) were characterized by high-resolution ESI-MS and IR and ¹H and ¹³C­{¹H} NMR spectroscopies and single crystal X-ray diffraction for <b>29</b>·CDCl₃. Theoretical density functional theory calculations were carried out for the investigation of the reaction mechanism, interpretation of the reactivity of Pt-bound and free nitriles toward azomethine imines and analysis of the regio- and stereoselectivity origin