Stability of Hierarchically Formed Titanium(IV) Tris(catecholate ester) Helicates with Cyclohexyl Substituents in DMSO

Inorganic Chemistry, vol. 59, pp. 1758–1762

Abstract

A cyclohexyl substituent strongly prefers the chair conformation with large substituents in equatorial positions, while other cycloalkyls are structurally more flexible. In hierarchically formed dimeric titanium(IV) tris(catecholates) equatorial versus axial connection of the cyclohexane to the ester results in either a more compact (axial) or more expanded (equatorial) structure. In DMSO solution the axial position results in a compact structure which minimizes solvophobic effects, leading to higher stability. However, computational investigations indicate that additionally intramolecular London dispersion interactions significantly contribute to the stability of the dimer. Thus, weak side-chain-side-chain interactions are responsible for the high stability of cyclohexyl ester derivatives with axial compared to equatorial ester connection.

Authors 7

1. Marcel Schlottmann Aachen Institut für Organische Chemie

   RWTH Aachen University

   Affiliation as printed

   Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

2. David Van Craen Aachen Institut für Organische Chemie

   RWTH Aachen University

   Affiliation as printed

   Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

3. Julia Baums Aachen Institut für Organische Chemie

   RWTH Aachen University

   Affiliation as printed

   Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

4. Ignacio Funes‐Ardoiz Aachen Institut für Organische Chemie

   RWTH Aachen University

   Affiliation as printed

   Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

5. Constanze Wiederhold Aachen Institut für Anorganische Chemie

   RWTH Aachen University

   Affiliation as printed

   Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

6. Iris M. Oppel Aachen Institut für Anorganische Chemie

   RWTH Aachen University

   Affiliation as printed

   Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany

7. Markus Albrecht corresponding Aachen Institut für Organische Chemie

   RWTH Aachen University

   Affiliation as printed

   Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany