Syntheses and X-ray crystal structures of zinc complexes with an amido-diamine ligand

The synthesis and characterization of complexes with a tridentate amido-diamine ligand –N(CH2CH2NMe2)2, [ClZnN(CH2CH2NMe2)2]2 (1), [EtZnN(CH2CH2NMe2)2]2 (2), {Zn[N(CH2CH2NMe2)2]2}2 (3) and [iBu2NZnN(CH2CH2NMe2)2]2 (4), are described. Compounds 1 (57% yield) and 2 (49% yield) were obtained from the reactions of ZnCl2 with 1 equiv. of LiN(CH2CH2NMe2)2 and ZnEt2 with excess HN(CH2CH2NMe2)2, respectively. Compounds 3 (52% yield) and 4 (75% yield) were isolated from the reactions of [Zn(NiBu2)2]2 with HN(CH2CH2NMe2)2 in 1:4 and 1:2 molar ratios, respectively. Mass spectral data and NMR analyses suggested that all four compounds were dimeric. The solid-state structures of compounds 2 and 3 were determined via X-ray crystallography. Both compounds were centrosymmetric containing a four-membered Zn2N2 ring with bridging amido ligands. In both structures, one NMe2 group in each bridging ligand bonded to a Zn center forming a five-membered ring. The ethyl groups in 2 and the second –N(CH2CH2NMe2)2 ligand in 3 occupied the terminal positions.

Graphical abstractZinc complexes with an amido-diamine ligand, LZnN(CH2CH2NMe2)2 (L = Cl, Et, N(CH2CH2NMe2)2 and NiBu2), were synthesized and characterized. Mass spectral, NMR and X-ray structural analyses indicated that these compounds were dimeric with bridging N(CH2CH2NMe2)2 ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide