Gas-Phase Ion-Molecule Reactions of Copper Hydride Anions [CuH2](-) and [Cu2H3]().

Title Gas-Phase Ion-Molecule Reactions of Copper Hydride Anions [CuH2](-) and [Cu2H3]().
Authors A. Zavras; H. Ghari; A. Ariafard; A.J. Canty; R.A.J. O'Hair
Journal Inorg Chem
DOI 10.1021/acs.inorgchem.6b02145
Abstract

Gas-phase reactivity of the copper hydride anions [CuH2](-) and [Cu2H3](-) toward a range of neutral reagents has been examined via multistage mass spectrometry experiments in a linear ion trap mass spectrometer in conjunction with isotope labeling studies and Density Functional Theory (DFT) calculations. [CuH2](-) is more reactive than [Cu2H3](-), consistent with DFT calculations, which show it has a higher energy HOMO. Experimentally, [CuH2](-) was found to react with CS2 via hydride transfer to give thioformate (HCS2(-)) in competition with the formation of the organometallic [CuCS2](-) ion via liberation of hydrogen; CO2 via insertion to produce [HCuO2CH](-); methyl iodide and allyl iodide to give I(-) and [CuHI](-); and 2,2,2-trifluoroethanol and 1-butanethiol via protonation to give hydrogen and the product anions [CuH(OCH2CF3)](-) and [CuH(SBu)](-). In contrast, the weaker acid methanol was found to be unreactive. DFT calculations reveal that the differences in reactivity between CS2 and CO2 are due to the lower lying ?* orbital of the former, which allows it to accept electron density from the Cu center to form the initial three-membered ring complex intermediate, [H2Cu(?(2)-CS2)](-). In contrast, CO2 undergoes the barrierless side-on hydride transfer promoted by the high electronegativity of the oxygen atoms. Side-on SN2 mechanisms for reactions of [CuH2](-) with methyl iodide and allyl iodide are favored on the basis of DFT calculations. Finally, the DFT calculated barriers for protonation of [CuH2](-) by methanol, 2,2,2-trifluoroethanol, and 1-butanethiol correlate with their gas-phase acidities, suggesting that reactivity is mainly controlled by the acidity of the substrate.

Citation A. Zavras; H. Ghari; A. Ariafard; A.J. Canty; R.A.J. O'Hair.Gas-Phase Ion-Molecule Reactions of Copper Hydride Anions [CuH2](-) and [Cu2H3]().. Inorg Chem. 2017. doi:10.1021/acs.inorgchem.6b02145

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See more Copper products. Copper Bohr Model Copper (atomic symbol: Cu, atomic number: 29) is a Block D, Group 11, Period 4 element with an atomic weight of 63.546. The number of electrons in each of copper's shells is 2, 8, 18, 1 and its electron configuration is [Ar]3d10 4s1. The copper atom has a radius of 128 pm and a Van der Waals radius of 186 pm. Copper was first discovered by Early Man prior to 9000 BC. In its elemental form, copper has a reddish-orange metallic and lustrous appearance. Of all pure metals, only silver Elemental Copperhas a higher electrical conductivity. The origin of the word copper comes from the Latin word 'cuprium' which translates as "metal of Cyprus," as the Mediterranean island of Cyprus was known as an ancient source of mined copper..

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