Sodium Salts of the Bipyridine Dianion: Polymer [(bpy) ²⁻ {Na ⁺ (dme)} ₂ ] _∞ , Cluster [(Na ₈ O) ⁶⁺ Na ⁺ ₆ (bpy) ₆ ²⁻ (tmeda) ₆ ], and Monomer [(bpy)

Abstract

Bipyridine, a workhorse among the ligands of complex chemistry, can be reduced with sodium to its dianion. Depending on the solvent different sodium salts crystallize: from dimethoxyethane/toluene a polymer, from tetramethylethylenediamine/benzene a lipophilically wrapped [Na O] cluster, and from pure pentamethyldiethylenetriamine a normal Na -bpy salt (see picture) are obtained.

Iron Dicarbonyl Complexes Featuring Bipyridine‐Based PNN Pincer Ligands with Short Interpyridine CC Bond Lengths: Innocent or Non‐Innocent Ligand?

“…Experimental CC bond lengths, determined by X‐ray diffraction, for bpy 0 , bpy . − , and bpy 2− , are approximately 1.49,32 1.43,33 and 1.40‐1.36 Å,34 respectively. This suggests that the bpy‐based ligands in 5 – 7 could be considered as radical anions, with the missing spin attributable to antiferromagnetic coupling of the unpaired electron on a low‐spin Fe I center.…”

The tmbp Dianion in the Contact Ion Pair [(tmbp)Na2(dme)1.5]n and in the Solvent-Separated Ion Pair [tmbp][(2.2.1)Li]2

“…[2] Whereas reduction processes of unsaturated carbon [3] and nitrogen derivatives are now well documented, [4] that of sp 2 -hybridized phosphorus-based molecules and their related transition metal complexes constitute a new field. surfaces by adsorption of alkali metals.…”

The tmbp Dianion in the Contact Ion Pair [(tmbp)Na2(dme)1.5]n and in the Solvent-Separated Ion Pair [tmbp][(2.2.1)Li]2 This work was supported by the CNRS and the Ecole Polytechnique; tmbp=4,4′,5,5′-tetramethyl-2,2′-biphosphinine, DME=1,2-dimethoxyethane.

“…Furthermore they often yield fascinating structures that illustrate aggregation and solvation phenomena of cations,1 and constitute good models for the modification of solid surfaces by adsorption of alkali metals 2. Whereas reduction processes of unsaturated carbon3 and nitrogen derivatives are now well documented,4 that of sp 2 ‐hybridized phosphorus‐based molecules and their related transition metal complexes constitute a new field 5. Recently, we have shown that 2,2′‐biphosphinine dianions6a could be used efficiently to synthesize highly reduced transitions metal complexes through their reactions with various metal precursors;6 herein we shed some light on their very peculiar geometrical and electronic structures.…”