Mesomerization of S4-Symmetric Tetrahedral Chelate Complex [In4(L3)4]: First-Time Monitored by Temperature-Dependent 1H NMR Spectroscopy

✍ Scribed by Rolf W. Saalfrank; Harald Maid; Andreas Scheurer; Ralph Puchta; Walter Bauer

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 519 KB
• Volume: 2010
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.201000295

✦ Synopsis

Abstract

VT ^1^H NMR spectroscopy proved that a non‐dissociative and reversible mesomerization process links the tetranuclear indium(III) complexes meso‐(Δ,Δ,Λ,Λ)(P,P,M,M)‐3 and meso‐(Λ,Λ,Δ,Δ)(M,M,P,P)‐3′. During this process four tandem Bailar twists, resulting in the (Δ)/(Λ) isomerization at the indium centers, and the (P)/(M) inversion of the four coordinating face‐centered, helical ligands (L^3^)^3–^ are involved. In addition, gas‐phase DFT calculations (B3LYP/LANL2DZp) revealed a C~1~‐symmetric transition state (+21.9 kcal mol^–1^) for the mesomerization mechanism which connects 3 and 3′.