Reaction Control of Organopaliadium Complexes by Using Bidentate Porphyrin Ligand

由于卟啉配体的四齿性质，其有机金属络合物在有机金属化学中一直很少见。然而，金属有机配合物与双齿卟啉的结构和反应由于其作为一种功能化合物的应用而引起人们的极大兴趣。本文研究了N^&lt；21&gt；，N^&lt；22&gt；-桥联卟啉的钯配合物作为双齿配体的化学性质。双齿卟啉钯配合物的配位化学一般来说，与膦配体相比，氮给体配体与钯的配位作用较弱。我们发现，双齿卟啉与钯的配位作用远强于普通的双齿氮配体，如联吡啶。此外，核磁共振中的环电流效应和UV-Vis中的Soret带有助于阐明Pd配位空间的结构和反应。研究了(π-烯丙基)钯的反应行为。研究了钯的π-烯丙基配体的配位动力学。这种π-烯丙基配体的顺反异构化是通过一个Pd-N键的解离进行的。该过程的活化能比相应的联吡啶络合物的活化能大20千卡/摩尔。以较高的产率将CO、异氰化物和烯烃插入到Pd-甲基键(乙酰基)Pd和(甲亚胺)Pd络合物中，并通过中间络合物的分离和精确的动力学测定，阐明了插入反应的机理。通过将苯乙烯插入Pd-甲基和Pd-乙酰键，合成了(π-苄基)Pd卟啉。通过X-射线结晶学和核磁共振仪研究了π-苄基配体的动力学行为。双齿卟啉Rh络合物的合成双齿卟啉Rh络合物的分子结构已被证明。

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.