Abstract
The synthesis and crystal structure of the title racemic compound, [Co(C2H8N2)3]Cl3.{[Na(H2O)6]Cl}0.5, are reported. The trivalent cobalt atom, which resides on a crystallographic threefold axis, is chelated by a single ethyl-ene di-amine (en) ligand and yields the tris-chelate [Co(en)3]3+ cation with distorted octa-hedral geometry after the application of crystal symmetry. The sodium cation (site symmetry ), has a single water mol-ecule bound to it in the asymmetric unit and yields a distorted, octa-hedrally coordinated hydrated [Na(H2O)6]+ cation after the application of symmetry. One of the chloride ions lies on a general position and the other has site symmetry. An extensive array of C-H⋯O, N-H⋯Cl and O-H⋯Cl hydrogen bonds exists between the ethyl-ene di-amine ligands, the water mol-ecules of hydration, and the anions present, thereby furnishing solid-state stability.
Highlights
The coordination complex-cation tris-ethylenediamine cobalt(III), [Co(en)3]3+, was influential in Werner’s development of the structure of transition-metal complexes as it could be resolved into its two enantiomers by selective crystallization using tartrate anions, helping to demonstrate the octahedral geometry of the metal ion (Werner, 1912)
The asymmetric unit consists of a trivalent cobalt atom residing on a threefold axis chelated by an ethylene diamine ligand
Solid-state integrity is maintained by an array of C—HÁ Á ÁO, N—HÁ Á ÁCl and O—HÁ Á ÁCl hydrogen bonds between the [Co(en)3]3+ and [Na(H2O)6]+cations and the chloride anions
Summary
The coordination complex-cation tris-ethylenediamine cobalt(III), [Co(en)3]3+, was influential in Werner’s development of the structure of transition-metal complexes as it could be resolved into its two enantiomers by selective crystallization using tartrate anions, helping to demonstrate the octahedral geometry of the metal ion (Werner, 1912). The synthesis of members of this family of complexes is a common undergraduate laboratory experiment (Work & McReynolds, 1946; Broomhead et al, 1960; Girolami et al, 1999; McClellan & Cass, 2015). The synthesis and structural characterization of many members of this family of complexes, both racemic and resolved, have been undertaken over the years. The [Co(en)3]3+ complex cation was found to have trigonally distorted octahedral symmetry, as expected, and the structures usually have significant hydrogen-bonding interactions involving the ethylene diamine ligands, the water molecules of hydration, and the anions present
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
