Results
Title

Crystal structure of strontium Di[bis(iminodiacetato)cobaltate(III)] pentahydrate, Sr[ cis(N)-Co( Ida)] · 5HO.

Authors

Polyakova, I.; Poznyak, A.; Sergienko, V.

Abstract

Compound Sr[ cis(N)-Co( Ida)] · 5HO ( I) is synthesized and its crystal structure is determined. The crystals are built of [Co( Ida)] anionic complexes, [Sr(HO)] hydrated cations, and crystallization water molecules. Two independent anions are located on rotation axis 2 and have close structures. A distorted octahedral coordination of Co atoms is formed by two N atoms and four O atoms of two Ida ligands [Co-N, 1.932(3) and 1.940(3) Å; Co-O, 1.879-1.899(3) Å]. [Sr(HO)] cations randomly occupy half of the positions in the vicinity of centers of inversion. In addition to three water molecules, the environment of the Sr atom includes five O atoms of five Ida ligands [Sr-O, 2.487(3)-2.889(5) Å]. Because of the disordering of [Sr(HO)] cations, the structural function of the Ida ligands varies from tridentate chelate to pentadentate bridging chelate. Sr-O and hydrogen bonds connect structural elements into a three-dimensional framework. The structure of I is compared with that of a related compound Sr[Co Edta]·9HO ( II). It is shown that the formation of N-H...O hydrogen bonds, which connect [Co( Ida)] anionic complexes in I into compact chains, is an important factor leading to the difference between packings I and II.

Subjects

CRYSTAL structure; STRONTIUM; CRYSTALLIZATION; HYDROGEN bonding; CHELATES; METAL complexes

Publication

Crystallography Reports, 2012, Vol 57, Issue 2, p241

ISSN

1063-7745

Publication type

Academic Journal

DOI

10.1134/S1063774512020150