Preparation Of Graphene Oxide- Copper Phthalocyanine Hybrid And Its Application In Catalystic Reduction Of Nitro Aromatics

Aromatic amines,as an important kind of organic intermediate,are applied widely in the production of dyes,medicines,pesticides,surfactants,curing agents,textile auxiliary agents etc.Preparation aromatic amines from the reduction of corresponding nitro aromatics in the presence of heterogeneous catalyst is a crucial method in organic synthesis,research on this class of catalysts with high efficiency,high chemoselectivity,excellent reusability and durability is always a hotspot in the field of chemistry.Graphene,a two dimensionally arranged honeycomb lattice,is composed of one-atom-thick planer sheet of sp~2-bonded carbon atoms.Because of its unique structure,graphene has huge surface area and excellent mechanical,thermal,electric properties.As an ideal catalyst support,graphene has broad application prospects in the field of organic synthesis.Metallophthalocyanines are highly stable 18?-electron-conjugated macrocycles with remarkable tolerances to acid,base and heat.This class of compounds exhibits excellent electron donating ability and redox activity and it can catalyze different organic reactions according to the different metal atom which located in the center of the ring.In this paper,we synthesized graphene oxide-copper phthalocyanine hybrid(GO-NH-CO-CuPc)by using graphene oxide(GO)and tetramino-CuPc(TACuPc)via amidation reaction.The morphology of the hybrid was firstly investigated by scanning electron microscope(SEM),and then transform infrared spectrograph(FT-IR),ultraviolet visible absorption spectroscopy(UV-vis),Raman spectra(Raman)were utilized to confirm the formation of amino bond between GO and TACuPc.The prepared GO-NH-GO-CuPc was then established as catalyst for the reduction of nitro aromatics to corresponding aromatic amines.Different cupreous catalysts,solvents,hydrogen sources and reaction temperatures were studied by using nitrobenzene as test substrate in order to assess the best reaction conditions.Furthermore,the scope of GO-NH-GO-CuPc catalyst was explored by reducing nitro aromatics containing different functional groups.The result indicated that GO-NH-GO-CuPc was a highly efficient catalyst for the chemoselective reduction of nitro aromatics which tolerating a large range of functional groups such as halo,acid,ester,nitrile in the presence of hydrazine hydrate by using DMF as solvent and the catalytic activity unchanged after three times of reuse.