The Synthesis, Isolation and Characterization of the Λ and Δ forms of Co(en)₃³⁺ and Co(diNOsar)³⁺

In the following experiment we will synthesize and isolate the Λ and Δ isomers of Co(en)₃³⁺.
We will then convert the resolved products to the corresponding Λ and Δ isomers of Co(diNOsar)³⁺.

The synthetic procedures found in your lab manual have been modified from those found in the following three references:

1. G.S. Girolami, T.B. Rauchfuss, R.J. Angelici, Synthesis and Technique in Inorganic Chemistry, A Laboratory Manual, 3rd Edition Univerisity Science Books, Sausalito, CA, 1999, pages 143-150.
2. The 2^nd Edition of the text listed above, Experiment 8, pages 71-80
3. J. M. Harrowfield, G. A. Lawrance, A. M. Sargenson; "Facile Synthesis of a Macrobicyclic Hexamine Co(III) Complex Based on Tris(ethylenediamine)Cobalt(III), An Advanced Undergraduate Inorganic Laboratory Experiment", J. Chem. Educ., Vol 62, No 9., 1985 p. 804-5.

Characterization:

1. [Co(en)₃]³⁺ products:
   • ¹H and ¹³C NMR
   • Conformation of Chiral Resolution and Determination of the ee by polarimetry and CD
   • Assignment of Absolute Configuration and Analysis of Conformers through Model Building and Visualizations
   • Determine of concentrations for CD by UV-Vis Spectroscopy
   • Determination of the relative stabilities of the conformers by molecular modeling computations using Gaussian 09
2. [Co(diNOsar]³⁺ products:
   • ¹H and ¹³C 1D-NMR
   • COSY, HETCOR and NOESY 2D-NMR and assignment of all 1H and 13C signals facilitated through structural analysis and Visualizations
   • Assignment of Absolute Configuration and Determination of ee by CD
   • Determine of concentrations for CD by UV-Vis Spectroscopy