Evidence based on crystal structures and calculations of a C-H-...pi interaction between an organic moiety and a chelate ring in transition metal complexes

Abstract

Structural and computational evidence is given for a special type of C-H(...)pi interaction where the C-H group interacts with the pi-system of a six-membered chelate ring. An investigation of crystal structures shows that these interactions take place in quite a number of metal complexes, including organometallic compounds; in the CSD we found over 1200 structures with these interactions, These interactions exist in complexes of different metals and various chelate rings, DFT calculations on three model systems show that the energy of these interactions is about 1 kcal/mol. ((C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).