Vanicek Stefan, Podewitz Maren, Hassenrück Christopher, Pittracher Michael, Kopacka Holger, Wurst Klaus, Müller Thomas, Liedl Klaus R, Winter Rainer F, Bildstein Benno
Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Center for Chemistry and Biomedicine, Innrain 80-82, 6020, Innsbruck, Austria.
Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 784557, Konstanz, Germany.
Chemistry. 2018 Mar 2;24(13):3165-3169. doi: 10.1002/chem.201800147. Epub 2018 Feb 5.
Oxidative addition of cobaltoceniumdiazonium bis(hexafluoridophosphate) with (pseudo)halide aurates gave gold(III) complexes containing zwitterionic cobaltoceniumide as a ligand. Its selenium derivative, cobaltoceniumselenolate, was obtained by an electrophilic aromatic substitution reaction of iodocobaltocenium iodide with Na Se. Spectroscopic and structural data in combination with DFT calculations showed that this cobaltocenylidene species is a mesoionic carbene quite different from common N-heterocyclic carbenes. Its ligand properties (TEP, singlet-triplet gap, nucleophilicity, π-acidity, Brønsted basicity) are in part comparable to those of cyclic (amino)(alkyl/aryl)carbenes. Electrochemistry data showed that the mesoionic cobaltoceniumides are more electron-rich than their parent ferrocenes. The reversible reduction of the tricyanido gold complex appears 50 mV negative of the cobaltocenium/cobaltocene couple, whereas that of the selenide derivative is shifted cathodically by 550 mV.
钴茂二氮鎓双（六氟磷酸）与（拟）卤化金酸盐的氧化加成反应生成了以两性离子钴茂鎓为配体的金（III）配合物。其硒衍生物钴茂硒醇盐是通过碘代钴茂碘与Na₂Se的亲电芳香取代反应制得的。光谱和结构数据结合密度泛函理论计算表明，这种钴茂叉物种是一种内盐型卡宾，与常见的N-杂环卡宾有很大不同。其配体性质（TEP、单重态-三重态能隙、亲核性、π-酸性、布朗斯特碱性）部分与环状（氨基）（烷基/芳基）卡宾相当。电化学数据表明，内盐型钴茂鎓比其母体二茂铁富电子。三氰基金配合物的可逆还原电位比钴茂鎓/钴茂电对负5０ mV，而硒化物衍生物的还原电位则向阴极移动了550 mV。
