Synthesis and coordination of a pair of isomeric ferrocene phosphinoamines

Ferrocene P,N-ligands have been extensively studied due to their favorable catalytic properties. This contribution focuses on a pair of new, isomeric ferrocene phosphinoamines, FcNHCH2CH2PPh2 ( 1 ) and FcN(Me)CH2PPh2 ( 2 ), which were prepared from aminoferrocene, converted to the respective phos-phine selenides ( 1-Se and 2-Se ) and further studied as ligands in Pd(II) complexes containing the 2-(dimethylamino-xN)phenyl-xC1 auxiliary (LNC) ligand. Thus, cleavage of the dimeric precursor [(LNC)Pd(it- Cl)]2 with the phosphinoamines afforded the corresponding phosphine complexes [(LNC)PdCl(1-xP)] ( 5 ) and [(LNC)PdCl(2-xP)] ( 6 ) with trans-P,N configuration. The subsequent removal of the chloride ligand with AgClO4 from 5 produced the cationic bis-chelate complex [(LNC)PdCl(1-x2P,N)]ClO4 ( 7 ), whereas an analogous reaction with 6 gave no defined product. The phosphinoamines and their complexes were char-acterized by elemental analysis and common spectroscopic methods, and the crystal structures of 1, 2 , and 7 were determined by single-crystal X-ray diffraction analysis. A cyclic voltammetry study, supported by DFT calculations, revealed that the primary electrochemical oxidation of these compounds occurs at the ferrocene unit. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study focuses on a pair of new ferrocene phosphinoamines, which have favorable catalytic properties and have been characterized and studied using various experimental methods.