Structural NMR Studies on Aryl-Substituted π-Allyl–Pd(II) Complexes by Concerted Use of Gradient-Based Experiments

✍ Scribed by Ramón Malet; Marcial Moreno-Mañas; Francesca Pajuelo; Teodor Parella; Roser Pleixats

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 553 KB
• Volume: 35
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199704)35:4<227::aid-omr69>3.0.co;2-6

✦ Synopsis

Complete 1H and 13C NMR assignments of several aryl-substituted p-allyl-Pd(II) complexes were achieved using modern gradient-based 1D and 2D experiments. In addition, unambiguous 31P assignments were readily made using an improved gradient-enhanced 1H-31P HMBC experiment from which the regiochemistry of cationic complexes containing asymmetric bidentate ligands could also be elucidated. The e †ect of the nature of the substituent on allylic proton and carbon chemical shifts is brieÑy evaluated. Finally, a partial p-r-p isomerization mechanism is proposed taking into account some observed dynamic NMR processes which are largely dependent on the ligand nature of these complexes. 1997