Fluxional chloro-pyrrole–Pd(ii) complex to cationic η2-pyrrole–Pd(ii) complex: subtlety in structure-directed bonding mode

• Published in: New journal of chemistry Vol. 45; no. 24; pp. 10594 - 10598
• Main Authors: Saha, Debajyoti, Sepay, Nayim
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2021
• Subjects: Carbon; Cations; Chlorine; Coordination; Crystallography; Palladium; Room temperature
• DOI: 10.1039/d1nj00866h
• ISSN: 1144-0546

Fluxionality in η1-aromatic carbocyclic-ligated Pd(ii) complexes is retained if the η1-carbon is replaced with an N atom through “hemilabile” palladium–carbon η1-pyrrole ligation. Herein, we report and characterize a tetra-coordinated neutral chloro-pyrrole–Pd(ii)-π-allyl complex, which shows dynamic behavior at room temperature. Upon chlorine abstraction by AgSbF6, a cationic palladium complex is formed, where the coordination sphere of the metal is completed by the coordination of one C=C double bond of the pyrrole ring. This cationic η2-pyrrole-ligated Pd(ii)-π-allyl complex was characterized crystallographically. The coordination mode of the pyrrole in these isostructural complexes subtly changes with a change in carbon ligand (σ or π).