Synthesis and modeling of alicyclic organic ligands

Abstract

The study of alicyclic cage molecules has in recent years increased due to the possibilities in application of these compounds. The photocyclization of the endo conformation Diels-Alder adduct of p-benzoquinone and cyclopentadiene yields the pentacyclic cage compound derivative pentacyclo[5.4.0.02,6.03,10.05,9]undecane that is a classical starting compound for the synthesis of different alicyclic cage compounds. An important part in the study of alicyclic cage compounds is the possible use of these compounds as ligands in metal complexes. Literature studies showed that limited research is being done in the field of alicyclic cage ligand activity and catalysis. Marchand et al. and Lee et al. synthesized alicyclic cage compounds that have the ability bind to transition metals to form relative stable alicyclic-metal complexes Different pentacyclo[5.4.0.02,6.03,10.05,9]undecylamines was identified in literature and synthesised in this study. These ligands was characterised using MS, IR and NMR and investigated by molecular modelling using Accelrys Material Studio and Spartan Pro. The ligand activity of these compounds was investigated by using lithium tetrachloropalladate(II) that lead to the formation of cyclopalladation complexes. Ligand 1,2,3 and 5 were investigated and formed very stable metal-ligand complexes with the palladium metal. These complexes were characterised using FAB+ M.S, 1H and 13C NMR, I.R and ESEM with a INCA 400 EDS system.