Reduction of 2,2′-Bipyridine by Quasi-Linear 3d-Metal(I) Silylamides—A Structural and Spectroscopic Study

Christian Schneider,Clemens Pietzonka,C Gunnar Werncke,Florian Kraus,Igor Müller

doi:10.3390/inorganics7100117

Christian Schneider, Clemens Pietzonka + Show 3 more

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https://doi.org/10.3390/inorganics7100117

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Journal: Inorganics	Publication Date: Sep 25, 2019
Citations: 19	License type: CC BY 4.0

Affiliation: Philipps University of Marburg

Abstract

Quasi-linear anionic 3d-metal(I) silylamides are a new and promising class of molecules. Due to their highly negative reduction potential we wanted to test their capability to reduce substrates under coordination of their monoanionic radicaloid form. In a proof of principle study, we present the results of the reaction of metal(I) silylamides of chromium to cobalt with 2,2′-bipyridine (bipy), the redox non-innocence and reducibility of which was already established. In the course of these studies complexes of the type K{18-crown-6}[M(hmds)2(bipy)] (hmds = –N(SiMe3)2) were obtained. These compounds were isolated and thoroughly characterized to confirm the electron transfer onto the bipyridine ligand, which now acts as a radical monoanion. For comparison of the structural changes of the bipyridine ligand, the analogous zinc complexes were also synthesized. Overall our results indicate that anionic metal(I) silylamides are capable of reducing and ligate substrates, even when the electrochemical reduction potential of the latter is by up to 1 V higher.

Highlights

Complexes with two-coordinate 3d-metal(I) ions are a rare class of molecules in coordination chemistry [1,2,3,4,5,6,7,8,9,10,11,12,13]
In all cases an hmds isolated (Fe and synthesized situ immediate reaction was visible by acomplex change (Cr–complex 8 (Co)), of color toeither intense dark green
We presented the facile reaction of two-coordinate 3d-metal(I) silylamides (Cr−Co) with

Summary

Introduction

Complexes with two-coordinate 3d-metal(I) ions are a rare class of molecules in coordination chemistry [1,2,3,4,5,6,7,8,9,10,11,12,13] They combine an uncommon coordination motif with an, for these metals, unusual oxidation state (with the exception of Cu and to a certain extent nickel). Their scarcity can be explained by the difficulties of stabilizing the electronically and coordinatively unsaturated metal ion. Such complexes can mediate the cleavage of H2 [12] and C–halide bonds [14] or the trimerization of alkynes [15]

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