Cr(III)-Tetraaza Macrocyclic Complexes Containing Auxiliary Ligands (Part IV); Synthesis and Characterization of Cr(III)-Acetylacetonato, -Malonato and -Oxalato Macrocyclic Complexes

Bulletin of the Korean chemical society

Chung Hun Han¹  Jong Chul Byun¹ 

关键词: Macrocyclic Cr(III) complex;    Acetylacetonato ligand;    Crystal structure;    Electronic absorption spectra;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

The reaction of cis-[Cr([14]-decane)(OH)₂]+ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11- teraazacyclotetradecane) with auxiliary ligands {L_a = acetylacetonate (acac), oxalate (ox) or malonate (mal)} leads to a new cis-[Cr([14]-decane)(acac)](ClO₄)₂·(1/2)H₂O (1), cis-[Cr([14]-decane)(ox)]ClO₄·(1/2)H₂O (2) or cis-[Cr([14]-decane)(mal)]ClO₄·(1/4)H₂O (3). These complexes have been characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[Cr([14]-decane)(acac)](ClO₄)₂·(1/2)H₂O reveals that central chromium(III) has a distorted octahedral coordination environment and two acetylacetonate-oxygen atoms are bonded to the chromium(III) ion in the cis positions. The angle N_axial-Cr-N_axial deviates by 11^o from the ideal value of 180^o for a perfect octahedron. The bond angle O-Cr-O between the chromium(III) ion and the two acetylacetonate-oxygen atoms is close to 90^o. The bond lengths of Cr-O between the chromium and the acetylacetonate-oxygen atoms are 1.950(3) and 1.954(2) A. They are shorter than those between chromium and nitrogen atoms of the macrocycle. The IR spectra of 1, 2 and 3 display bands at 1560 {�? (C=O)}, 1710 {�?_as(OCO)} and 1660 cm^-1 {�?_as(OCO)} attributed to the acac, ox and mal auxiliary ligands stretching vibrations, respectively.

【 授权许可】

Unknown