Reaction Control of Organopaliadium Complexes by Using Bidentate Porphyrin Ligand

点击翻译按钮获取中文摘要

Organometallic complexes of porphyrins have been rather of unusual in organometallic chemistry because of the tetradentate nature of porphyrin ligand. However, structure and reaction of organometallic complexes with bidentate porphyrin is of great interest in view of its utility as a functional compound. The chemistry of Pd complexes of N^<21>, N^<22>-bridged porphyrin as a bidentate ligand has been studied in this work.1. Coordination chemistry of Pd complexes of bidentate porphyrinGenerally speaking, nitrogen donor ligand weakly coordinates to Pd in comparison with phosphine ligand. We have found that coordination of bidentate porphyrin to Pd is much stronger than that of ordinary bidentate nitrogen ligand such as bipyridine. Furthermore, ring current effect in the NMR and Soret band in UV-vis are helpful in elucidating structure and reaction of Pd coordination sphere.2. Reaction behavior of (π-allyl)Pd porphyrinCoordination dynamics of the π-allyl ligand of Pd porphyrin has been studied. This cis-trans isomerization of the π-allyl ligand occurs by way of dissociation of one Pd-N bonding. Activation energy of this process is by 20 Kcal/mol larger in comparison with that of the corresponding bipyridine complex.3. Insertion reaction of CO, isocyanide, and alkenes into Pd-methyl bond(Acetyl)Pd and (methylimino)Pd complexes have been obtained in good yield and mechanism for the insertion process have been elucidated through the isolation of intermediate complexes and precise kinetic measurements. (π-Benzyl)Pd porphyrins have been prepared by the insertion of styrenes into Pd-methyl and Pd-acetyl bonds. Dynamic behavior of the π-benzyl ligand was elucidated by X-ray crystallography and NMR measurement.4. Synthesis of rhodium complexes of bidentate porphyrinsMolecular structures of Rh complexes of the bidentate porphyrin have been shown.