Erste Reaktion von Dizinkocen unter Erhalt der Zn‐Zn‐Bindung

Abstract

Eine unerwartete Reaktion: [${{{\rm {\rm Cp}}{{{\ast}\hfill \atop 2\hfill}}}}$Zn2] reagiert mit der starken Lewis‐Base 4‐Dimethylaminopyridin (dmap) in vierfachem Überschuss zum unerwarteten Lewis‐Säure‐Base‐Addukt 1, in dem zwei dmap‐Moleküle unter Erhaltung der Zn‐Zn‐Bindung geminal an ein Zn‐Zentrum binden. Cp*=C5Me5.

Zincocene and Dizincocene N‐Heterocyclic Carbene Complexes and Catalytic Hydrogenation of Imines and Ketones

“…14,16] The molecular solid-state structures of 14 and 15 were established and revealed the Cp* rings on the Zn atom to which the carbene binds to adopt slipped binding modes ( Figure 5). The ZnÀZn bond lengths are 2.3392(4) and 2.3682(6) for 14 and 15, respectively, and are between the corresponding distances observed for the parent compound 2 (2.305(3) ) [20a] and [Zn 2 Cp* 2 (dmap) 2 ] (dmap = 4-dimethylaminopyridine 2.418 (1) ) [24] and within the general range for www.chemeurj.org Zn 2 R 2 compounds. [19c] Although one ring remains coordinated in a slightly slipped h 5 -fashion (ZnÀC bond lengths: 2.269(4) to 2.384(4) for 14 and 2.323(5)-2.414(4) for 15), the other ring is best described as h 2 (ZnÀC 2.209(15)-2.472 (18) ) for 14 and h 3 (ZnÀC 2.126(4) to 2.548(4) ) for 15.…”

Cationic Cyclopentadienyl Zinc Complexes with Slipped Triple‐Decker and Half‐Sandwich Structures

“…Reactions with the strong Lewis base 4-dimethylaminopyridine (dmap) gave the corresponding Lewis acid-base adducts [ZnCp* 2 A C H T U N G T R E N N U N G (dmap)] and [Cp*ZnZnCp*A C H T U N G T R E N N U N G (dmap) 2 ]. [5] Only a limited number of structurally well-defined cationic organozinc compounds with the general formula [ZnRL n ] + (R = alkyl) have been reported so far. [6][7][8][9] In all cases, the presence of additional stabilizing donor ligands L is required.…”

Structural Characterization of a Base‐Stabilized [Zn2]2+ Cation

“…Our initial studies focused on reactions of [Cp* 2 Zn 2 ] (1) because of the promising steric and electronic flexibility of the Cp* substituent. [16] The reaction with 4-dimethylamino pyridine (dmap), which we have shown to be a valuable Lewis base for the synthesis of base-stabilized monomeric Group 13/15 compounds, [17] resulted in the formation of [Cp*Zn À Zn(dmap) 2 Cp*] (2), [18] in which the dmap molecules bind in a geminal coordination mode to only a single Zn atom.…”