Synthesis, Spectroscopy, Electrochemistry and DFT of Electron-Rich Ferrocenylsubphthalocyanines.

Pieter J Swarts,Jeanet Conradie

doi:10.3390/molecules25112575

Abstract

A series of novel ferrocenylsubphthalocyanine dyads Y-BSubPc(H)12 with ferrocenyl-carboxylic acids Y-H = (FcCH2CO2-H), (Fc(CH2)3CO2-H) or (FcCO(CH2)2CO2-H) in the axial position were synthesized from the parent Cl-BSubPc(H)12 via an activated triflate-SubPc intermediate. UV/Vis data revealed that the axial ferrocenyl-containing ligand did not influence the Q-band maxima compared to Cl-BSubPc(H)12. A combined electrochemical and density functional theory (DFT) study showed that Fe group of the ferrocenyl-containing axial ligand is involved in the first reversible oxidation process, followed by a second oxidation localized on the macrocycle of the subphthalocyanine. Both observed reductions were ring-based. It was found that the novel Fc(CH2)3CO2BSubPc(H)12 exhibited the lowest first macrocycle-based reduction potential (−1.871 V vs. Fc/Fc+) reported for SubPcs till date. The oxidation and reduction values of Fc(CH2)nCO2BSubPc(H)12 (n = 0–3), FcCO(CH2)2CO2BSubPc(H)12, and Cl-BSubPc(H)12 illustrated the electronic influence of the carboxyl group, the different alkyl chains and the ferrocenyl group in the axial ligand on the ring-based oxidation and reduction values of the SubPcs.

Highlights

IntroductionThe research of ferrocene-containing compounds thrives, and new research keeps on growing due to their varying successful applications
The discovery of ferrocene in 1951 [1] unlocked an entirely new research field and over the years ferrocene has been extensively studied and well-reviewed in organic and inorganic chemistry [2,3,4,5].The research of ferrocene-containing compounds thrives, and new research keeps on growing due to their varying successful applications
We report the synthesis, characterisation and electrochemical studies of three novel ferrocenylsubphthalocyanine dyads 8, 10 and 11

Summary

Introduction

The research of ferrocene-containing compounds thrives, and new research keeps on growing due to their varying successful applications. The electron-withdrawing carboxyl group directly bound to ferrocene in 1 and FcCO(CH2 ) CO2 H (5), led to an increase in the formal reduction potential of the ferrocene moiety compared to free ferrocene [13,14]. Subphthalocyanines such as ClBSubPc(H) , , have been used in research for almost 50 years [15]

Methods

Results

Conclusion