Sievers Robin, Hartmann Nick, Riemann Paulin S, Streit Tim-Niclas, Malischewski Moritz
Freie Universität Berlin, Institut für Chemie und Biochemie - Anorganische Chemie Fabeckstraße 34/36 14195 Berlin Germany
Chem Sci. 2025 May 27;16(26):11949-11953. doi: 10.1039/d5sc02784e. eCollection 2025 Jul 2.
The electron-deficient ferrocene [Fe(CH)(C(CF))] is complemented by the synthesis and full characterisation of the analogous bench-stable ruthenocene [Ru(CH)(C(CF))]. These complexes have been studied with respect to the substitution lability of the perfluorinated Cp* ligand under mild conditions. Photolysis of the metallocenes in MeCN converted the [C(CF)] ligand into a weakly coordinating anion. This gave access to the highly reactive piano-stool complexes [M(CH)(MeCN)][C(CF)] (M = Fe, Ru). The unstable iron half-sandwich complex dismutates under formation of [Fe(CH)] and [Fe(MeCN)][C(CF)]. It was trapped by the chelating diphosphine DPPE and isolated as thermally stable [Fe(CH)(DPPE)(MeCN)][C(CF)]. For [Ru(CH)(MeCN)][C(CF)] a thermally induced backreaction to ruthenocene is observed. This represents the first example of a reversible dissociation and recoordination of a cyclopentadienyl ligand, initiated by light and heat.
缺电子的二茂铁[Fe(CH)(C(CF))]通过合成和对类似的易于保存的二茂钌[Ru(CH)(C(CF))]进行全面表征得到补充。对这些配合物在温和条件下全氟代Cp*配体的取代活性进行了研究。金属茂在乙腈中的光解将[C(CF)]配体转化为弱配位阴离子。这使得能够得到高活性的“钢琴凳”配合物[M(CH)(MeCN)][C(CF)]（M = Fe，Ru）。不稳定的铁半夹心配合物歧化生成[Fe(CH)]和[Fe(MeCN)][C(CF)]。它被螯合二膦DPPE捕获，并作为热稳定的[Fe(CH)(DPPE)(MeCN)][C(CF)]分离出来。对于[Ru(CH)(MeCN)][C(CF)]，观察到热诱导的向二茂钌的逆反应。这代表了由光和热引发的环戊二烯基配体可逆解离和再配位的首个实例。
