Synthesis and Isomerisation Reactions of Tetranuclear and Octanuclear (Carbamato)zinc Complexes

Abstract

A new series of (diisopropylcarbamato)(oxido)zinc complexes were obtained by innovative synthetic approaches. (2) were synthesised by an identical reaction procedure involving protolysis of ZnEt 2 with iPr 2 NH/ CO 2 and followed by stoichiometric hydrolysis. Recrystallisation of the reaction product from nitrile solvents yielded the tetrazinc complex 1. Conversely, recrystallisation from alkane solvents yielded crystals of the octazinc complex 2. The two structural isomers were readily interconverted simply by recrystallisation from the appropriate solvent. Both complexes were structurally characterised by X-ray crystallogra-

Recent Advances in the Chemistry of Metal Carbamates

“…Homoleptic metal carbamato complexes have been widely investigated from this perspective. Carbamato ligands in metal complexes are usually able to exchange their position and their coordination modes in solution, as demonstrated by variable temperature NMR measurements [127,138,248,[283][284][285]. For instance, the two carbamato ligands in [Mg2Br2(μ-O2CNMePh)2] are fluxional, rapidly shifting from bridging (B/2) to bridging-chelating (C/2) mode down to 0 °C, when the exchange turns slow on the NMR time scale [248].…”

Hydrolysis of organometallic and metal–amide precursors: synthesis routes to oxo-bridged heterometallic complexes, metal-oxo clusters and metal oxide nanoparticles

“…Nonetheless, the quantity of strongly binding ligands can influence the growth of condensation products, either supporting small clusters or allowing growth of extended metal-oxide domains. If the precursors have a high ligand content then hydrolysis is likely to lead to small ligated metal-oxo-clusters, such as tetrahedral Zn4OL6 (L = carboxylate, carbamate, amidate, phosphinate or dialkylphosphate), 18,96,[101][102][103] formed through the straightforward stoichiometric hydrolysis of a 2:3 ratio of ZnEt2 and ligand. This tetrahedral unit has been commonly used as a vertex within MOFs and pre-assembled Zn4O(amidate)6 clusters act as a precursor to the mechanochemical formation of MOF-5.…”

“…Synthesis of Zn4OL6 clusters from ZnEt2 and reactions with excess water. 96,[101][102][103][104] Colours: O, red; Zn, blue; P, orange.…”

Synthesis and Reactivity of a New Oxidation‐Labile Heterobimetallic Mn6Zn2 Carbamate Cluster and Precursor to Nanosized Magnetic Oxide Particles

“…[11] This is up to now the only example in which partial oxidation of a carbamate complex with O 2 is reported. Examples of hexanuclear carbamate complexes include [Co 6 (O 2 -CNEt 2 ) 12 ] [12] and Mn n Mg 6-n (O 2 CNEt 2 ) 12 (n = 1-6), [13] and examples for structurally characterized octanuclear carbamate complexes comprise [Zn 8 (μ 4 -O) 2 (O 2 CNiPr 2 ) 12 ], [14] [Co 8 (μ 4 -O) 2 (O 2 CNiPr 2 ) 12 ], [15] [Fe 8 (μ 4 -O) 2 (O 2 CNiPr 2 ) 12 ], [16] [Zn 2 Ni 6 (μ 4 -O) 2 (O 2 CNiPr 2 ) 12 ], [17] and [Zn 8-n Mg n (μ 4 -O) 2 -(O 2 CNiPr 2 ) 12 ] (n = 0.62). [18] Tetranuclear Zn carbamate complexes of the form [ZnR(O 2 CNRЈ 2 )] 4 (R, RЈ = alkyl) are the products of reaction between RZnNRЈ 2 (or ZnR 2 /HNRЈ 2 mixtures) and CO 2 .…”