Structures of three cis-β1 and three cis-β2 isomers of [Co(trien)(aminoacidato)]2+ complexes

• Published in: Acta crystallographica. Section B, Structural science Vol. 57; no. 1; pp. 45 - 53
• Main Authors: Cai, Jiwen, Hu, Xiaopeng, Feng, Xiaolong, Ji, Liangnian, Bernal, Ivan
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01.02.2001; Blackwell
• Subjects: Condensed matter: structure, mechanical and thermal properties; configuration; crystallization behavior; Exact sciences and technology; Inorganic compounds; Metal complexes; packing features; Physics; structure; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Cationic complex; Inorganic compounds; Transition element complexes; Iodides; Stacking sequence; Molecular structure; Strain energy; Cobalt III Complexes; Organic ligand; XRD; Experimental study; Perchlorates; α-Aminoacid; Hydrogen bonds; Complexes Mixed; Absolute configuration; Tertiary amine; NMR spectra; Diastereomer; Hydrates; Crystal structure
• ISSN: 0108-7681; 1600-5740
• DOI: 10.1107/S0108768100013896

The crystal structures and absolute configurations of three cis‐β1 and three cis‐β2 isomers of [Co(trien)(l‐aminoacidato)]2+, namely β1‐Λ(SSS)(λλδ)/(λδδ)‐[Co(trien)(l‐isoleucinato)](ClO4)2, l‐isoleucinato(triethylenetetramine)cobalt(III) diperchlorate (1), β1‐Λ(SRS)(λδλ)‐[Co(trien)(l‐valinato)](ClO4)2, l‐valinato(triethylenetetramine)cobalt(III) diperchlorate (2), β1‐Δ(RSS)(δλδ)‐[Co(trien)(l‐pyroglutamato)]ClO4, l‐pyroglutamato(triethylenetetramine)cobalt(III) perchlorate (3), β2‐Δ(RRS)(δδλ)‐[Co(trien)(l‐isoleucinato)]I2·H2O, l‐iso­leucinato(triethylenetetramine)cobalt(III) diiodide monohydrate (4), β2‐Δ(RRS)(δδλ)‐[Co(trien)(l‐isoleucinato)](ClO4)2·2H2O, l‐isoleucinato(triethylenetetramine)cobalt(III) diperchlorate dihydrate (5), and β2‐Λ(SSS)(δλλ)[Co(trien)(l‐leucinato)](ClO4)2·2H2O, l‐leucinato(triethylenetetramine)cobalt(III) diperchlorate dihydrate (6), have been determined. Both β1 and β2 isomers form inter‐cation hydrogen‐bonding interactions through double or triple hydrogen bonds which link the cations into helices. However, the motifs of the interactions are different in β1 and β2 isomers, resulting in different packing structures. A localized hydrophobic area is observed in the packing structure of (1), a unique feature amongst these six structures. This work describes the first synthesis of the β1 isomer by direct reaction between amino acids and cis‐α‐[Co(trien)Cl2]Cl in mildly basic solution.