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Enthalpy vs Entropy Driven Complexation of Homoallylic Alcohols by Rh(I) Complexes
Sung Ok Kang1, Vincent M Lynch, Victor W Day
1Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712.
None:
The thermodynamics of binding between several homoallylic alcohols and simple olefinic Rh(I) compounds was examined with (1)H NMR spectroscopy and ITC. (1)H NMR titrations revealed moderate binding of these alcohols with [Rh(COD)(2)](+) (1) and [Rh(COD)(CH(3)CN)(2)](+) (3), but weaker binding with [Rh(NBD)(2)](+) (2). ITC indicated that the complexation with [Rh(COD)(2)](+) is mainly governed by enthalpy whereas binding with [Rh(COD)(CH(3)CN)(2)](+) is entirely driven by entropy. The thermodynamic parameters for the homoallylic alcohol binding of Rh(I) complexes 1-3 are consistent with crystallographic data.
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