Use of homogeneous catalysts poses the problem of their recovery at the end of the reaction. A possible strategy to circumvent this problem is to make the ligand part of a polymer with limited solubility. In this work, we investigated the immobilization of complexes of Ar-BIAN ligands (Ar-BIAN = bis(arylimido)acenaphthene). We employed 4,4′-methylene-bis(aniline) as an amine able to bridge two acenaphthene moieties. However, the obtained product was a mixture of short-chain oligomers. A ruthenium complex of this mixture (Oligo-BIAN) was indeed catalytically active in the model hydrogenation of nitrobenzene to aniline by CO/H2O but the complexes were too soluble in the reaction mixture to allow for an easy recovery. We thus further extended the molecular weight of Oligo-BIAN by polymerizing it with terephthaloyl chloride obtaining a polyamide (Poly-BIAN). The latter was insoluble in all solvents but its ruthenium complex was catalytically inactive in the model reaction. An deeper investigation, showed that coordination mode of monomeric Ar-BIAN ligands and Oligo-BIAN to [Ru(CO)3Cl2(THF)] is differs from that of Poly-BIAN. This result was completely unexpected and constitutes a general warning not to give for granted the coordination mode of a complex to a functionalized polymer.

Unexpected coordination behavior of ruthenium to a polymeric α-diimine containing the poly[bis(arylimino)acenaphthene] fragment / F. Ferretti, L. Rota, F. Ragaini. - In: INORGANICA CHIMICA ACTA. - ISSN 0020-1693. - 518:(2021 Apr 01). [10.1016/j.ica.2021.120257]

Unexpected coordination behavior of ruthenium to a polymeric α-diimine containing the poly[bis(arylimino)acenaphthene] fragment

F. Ferretti
Primo
;
F. Ragaini
Ultimo
2021

Abstract

Use of homogeneous catalysts poses the problem of their recovery at the end of the reaction. A possible strategy to circumvent this problem is to make the ligand part of a polymer with limited solubility. In this work, we investigated the immobilization of complexes of Ar-BIAN ligands (Ar-BIAN = bis(arylimido)acenaphthene). We employed 4,4′-methylene-bis(aniline) as an amine able to bridge two acenaphthene moieties. However, the obtained product was a mixture of short-chain oligomers. A ruthenium complex of this mixture (Oligo-BIAN) was indeed catalytically active in the model hydrogenation of nitrobenzene to aniline by CO/H2O but the complexes were too soluble in the reaction mixture to allow for an easy recovery. We thus further extended the molecular weight of Oligo-BIAN by polymerizing it with terephthaloyl chloride obtaining a polyamide (Poly-BIAN). The latter was insoluble in all solvents but its ruthenium complex was catalytically inactive in the model reaction. An deeper investigation, showed that coordination mode of monomeric Ar-BIAN ligands and Oligo-BIAN to [Ru(CO)3Cl2(THF)] is differs from that of Poly-BIAN. This result was completely unexpected and constitutes a general warning not to give for granted the coordination mode of a complex to a functionalized polymer.
Heterogenized catalysts; N-ligands; Polymeric ligands; Ruthenium; Schiff bases
Settore CHIM/03 - Chimica Generale e Inorganica
12-gen-2021
Article (author)
File in questo prodotto:
File Dimensione Formato  
Poly BIAN Author accepted manuscript.pdf

Open Access dal 21/01/2023

Tipologia: Post-print, accepted manuscript ecc. (versione accettata dall'editore)
Dimensione 771.18 kB
Formato Adobe PDF
771.18 kB Adobe PDF Visualizza/Apri
Poly_BIAN.pdf

accesso riservato

Tipologia: Publisher's version/PDF
Dimensione 921.04 kB
Formato Adobe PDF
921.04 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/823342
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? 2
social impact