Rare Earth Heterleptic Corrole-phthalocyanine Triple-decker Complexes:Synthesis,Electrochemical And Magnetic Properties

Extensive work has been done in the preparation and characterization of sandwich triple-decker phthalocyanines and/or porphyrins rare earth complexes,which have remarkable optical,electrical and electrochemical properties that stem from their inter-ring?-?interactions and rare earth ionic f-f interactions.These properties render them extensively application in the areas of catalysis,sensors,nonlinear optical materials and medicinal chemistry.Different from phthalocyanines and porphyrins,corroles are ring-contracted 18-?electron tetrapyrrolic macrocycles,which contain a direct carbon-carbon bond between two pyrrole rings and act as trianionic ligands because of three NH protons in the inner core.The special structure makes corroles exhibit unique physico-chemical properties.With the view to exploiting novel rare earth heteroleptic corrole-phthalocyanine triple-decker complexes towards potential applications in the fields of single-molecule magnets and information storage devices,a series of rare earth triple-decker complexes with one meso-substituted trans-A₂B-corrole or A₃-corrole and two phthalocyanine macrocycles have been designed and synthesized.Their optical,electrochemical,and magnetic properties were fully investigated.Our research work has been focused on the following respects:1.Constructing mixed corrole-phthalocyanine europium triple-decker complexes involving meso-substituted trans-A2B-corroleWith the view to exploiting novel rare earth heteroleptic corrole-phthalocyanine triple-decker complexes towards potential applications in the fields of information storage devices and nonlinear optical materials,three europium triple-decker complexes containing one meso-substituted trans-A₂B-corrole and two phthalocyanine macrocycles have been designed and synthesized.The investigated compounds are represented as Eu₂[Pc?OC₄H₉?₈]₂[Cor?p-R¹Ph?₂?p-R²Ph?],where Pc=phthalocyanine,Cor=corrole,?p-R¹Ph?and?p-R²Ph?are the substituents on the5,15-meso and 10-meso positions of the corrole macrocycle,respectively,R¹ is H and R² is a CH₃O,F or Cl substituent on the para-position of the meso-phenyl ring.These novel europium triple-decker complexes were characterized by spectroscopic and electrochemical techniques in nonaqueous media.Under excitation at 633 nm,a typical Raman marker band of the phthalocyanine dianions Pc^2-is observed at 1505cm^-1,resulting from the coupling of the C=C?pyrrole?and C=N?aza group?stretchings.The UV-visible spectra and redox potentials of each triple-decker were analyzed as a function of the sum of Hammett substituent constants for the para-substituents on meso-phenyl rings of the corrole macrocycle.2.Dysprosium heteroleptic corrole-phthalocyanine triple-decker complexes:Synthesis,crystal structure,electrochemical and magnetic propertiesDifferent from phthalocyanines and porphyrins,the special structure makes corroles exhibit unique physico-chemical properties,which render them extensively application in the areas of catalysis,sensors,nonlinear optical materials and medicinal chemistry.Despite this,the“periodic table of corrole complexes”is not as rich as that of porphyrins or phthalocyanines.Until now,there are only 42 kinds of elements,which can be coordinated with corrole ligands.Particularly,corrole complexes with rare earth metal ions are extremely rare.The first example of lanthanide corrole complexes?of La,Gd and Tb?was reported by Arnold et al in 2013.In recent years,we have successfully synthesized several rare earth corrole-phthalocyanine heteroleptic triple-decker complexes M₂Pc₂^*Cor^*?M=Y,Pr,Nd,Sm,Eu,Gd or Tb?.Herein,two triple-decker dinuclear sandwich dysprosium complexes which are represented as Dy₂[Pc(OC₅H₁₁)₈]₂[Cor?p-FPh?₃]and Dy₂[Pc(OC₅H₁₁)₈]₂[Cor?p-ClPh?₃]were synthesized and characterized by spectroscopic and electrochemical methods in nonaqueous media.Their electronic structures were also investigated on the basis of TD-DFT calculations.The sandwich triple-decker nature with the molecular conformation of[Pc(OC₅H₁₅)₈]Dy[Cor?FPh?₃]Dy[Pc(OC₅H₁₁)₈]was unambiguously revealed by single-crystal X-ray diffraction analysis and showed each dyprosium ion to be octa-coordinated by the isoindole and pyrrole nitrogen atoms of an outer phthalocyanine ring and the central corrole ring,respectively.In addition,the magnetic property of both compounds is also characterized for exploring the functionalities of these type triple-decker complexes.