Peripheral and non-peripheral-designed multifunctional phthalocyanines; synthesis, electrochemistry, spectroelectrochemistry and metal ion binding studies (original) (raw)
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Electroanalysis, 2012
The synthesis of novel tetra-substituted manganese and indium phthalocyanines was achieved by cyclotetramerization of corresponding phthalonitrile derivative. The new compounds have been characterized by using UV-vis, IR, 1 H NMR and mass spectroscopic data. Spectroelectrochemical characterization of an indium phthalocyanine complex was performed for the first time in this paper and its electrochemical and spectroelectrochemical responses were compared with manganese phthalocyanine, bearing a redox active metal center. Electrochemical and spectroelectrochemical measurements exhibit that incorporation of redox active metal ion, Mn III , instead of In III into the phthalocyanine core extends the redox capabilities of the complex including the metal-based reduction couples of the metal center and affect the aggregation behavior of the complexes. Presence of molecular oxygen in the electrolyte system affects the voltammetric and spectroelectrochemical responses of the phthalocyanines due to the interaction between the complexes and molecular oxygen. MnPc and InPc formed m-oxo species and this reaction changed the electrochemical and optic responses of the complexes, which are desired properties for sensor and electrocatalytic applications of a material. An in situ electrocolorimetric method has been applied to investigate the color of the electro-generated anionic and cationic forms of the complexes for possible electrochromatic applications and for clarify the interaction mechanism of the MnPc with molecular oxygen.
Journal of Porphyrins and Phthalocyanines, 2003
A new family of pyrrole substituted metallophthalocyanine complexes, namely cobalt(II), iron(II), manganese(III), nickel(II) and zinc(II) tetrakis-4-(pyrrol-1-yl)phenoxy phthalocyanines (noted as M(TPhPyrPc), where M is the metallic cation) have been synthesized and fully characterized. In particular, the UV-visible spectra of the iron and nickel complexes showed extensive aggregation even at low concentrations. The cyclic voltammetry of the cobalt, iron and manganese complexes showed three to four redox couples assigned to metal and ring based processes. Spectroelectrochemistry of the manganese derivative confirmed that the synthesized complex is Mn III (TPhPyrPc -2 ) and that the reduction of Mn II (TPhPyrPc -2 ) to be centred on the ring and rather than on the metal, forming the Mn II (TPhPyrPc -4 ) species. Also, the electrochemical polymerization of these newly synthesized pyrrole-substituted phthalocyanines has been demonstrated in the case of the cobalt complex and the electrocatalytic activity of the obtained film has been tested towards the oxidation of L-cysteine.
Polyhedron, 2007
Our efforts toward the development of the synthesis of a novel type of receptor ligand and its tetrasubstituted phthalocyanines, 2,9,16,23-tetrakis(6-hydroxyhexylsulfanyl) phthalocyanine, M[Pc(S-C 6 H 13 OH) 4 ] (M = Zn(II), Cu(II), Co(II)), bearing sulfur and oxygen donor atoms on the periphery together with hexyl moieties, have been carried out together with spectroscopic and electrochemical characterization. The newly synthesized functional phthalocyanines were soluble in MeOH, EtOH, THF, DMF, CNP (a-chloronapthalene), DMSO and quinoline, and less soluble in i-PrOH and CH 3 CN. Cation binding abilities of the functional phthalocyanines with Ag + , Pd 2+ , Hg 2+ and Cd 2+ , resulting in the formation of polynuclear phthalocyanine complexes, were evaluated by UV-Vis spectroscopic techniques. The spectroscopic properties of the complexes were affected strongly by the electron-donating sulfanyl units on the periphery. The cyclic voltammetry of the complexes were examined on a platinum electrode in DMSO. The new synthesized compounds have been characterized by elemental analysis, FTIR, 1 H and 13 C NMR, MS (ESI and MALDI-TOF) and UV-Vis spectral data.
Electrochemical Study of Tetra-15-Crown-5-Phthalocyanine and its Copper and Cobalt Complexes
Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 2009
The electrochemical behavior of tetra-15-crown-substituted phthalocyanine and its copper and cobalt complexes in solution have been studied by voltammetric techniques in wide range of potentials. It is established that the ligand undergoes an irreversible oxidation process, as well as its copper and cobalt complexes. The necessary correlations between electrochemical properties and structures of the ligand and its complexes are proposed.
Metal-free 4 and metallophthalocyanine complexes 5-7 (MPcs, M = Ni, Co, Cu) substituted with the electropolymerizable (2-{2-[3-(dimethylamino)phenoxy]ethoxy}ethoxy) group have been synthesized and their structure have been identified by IR, 1 H and 13 C NMR, mass and UV-Vis spectroscopy techniques. The electrochemical characterization of the phthalocyanines sustained the submitted structures of the complexes, since the half wave peak potentials of the redox processes are in harmony with the common electrochemical behavior of MPcs. CoPc gives a metal based reduction process in addition to the ligand based electron transfer processes, which enrich the possible usage of the complex in various electrochemical technologies. All the complexes were coated on the working electrode with an oxidative electopolymerization process during the anodic potential scans.
Dyes and Pigments, 2013
The synthesis and characterization of novel organosoluble peripherally tetra imidazole substituted metal-free (4), zinc(II) (5), nickel(II) (6), cobalt(II) (7), lead(II) (8) and oxo-titanium(IV) (9) phthalocyanines are described for the first time in this study. Electrochemical and spectroelectrochemical measurements exhibit that while copper phthalocyanine gives only ring-based electron transfer reactions, incorporating redox active metal centers, Co(II), and Ti(IV)OPc, into the phthalocyanine core extends the redox richness of the phthalocyanine ring with the metal-based reduction and oxidation couples of the metal centers in addition to the common phthalocyanine ring-based electron transfer processes. In-situ electrocolorimetric measurements of the complexes allow quantification of color coordinates of the each electrogenerated anionic and cationic redox species.
Journal of Chemical Research, 2012
A novel phthalocyanine bearing oxygen donor atoms on the peripheral positions has been synthesised by cyclotetramerisation of ( E)-4-(4-cinnamoylphenoxy) phthalonitrile and its nickel, zinc, cobalt, copper and lead derivatives prepared. The thermal stabilities of the phthalocyanine compounds have been determined and their possible biological activities (antibacterial, anticandidal and antifungal) studied. The effects of substituent on the electrochemical and in situ spectroelectrochemical behaviour of cobaltphthalocyanine have been investigated and an in situ electrocolorimetric method was applied to investigate the colour of the electrogenerated anionic and cationic forms of the complex.
Polyhedron, 2011
The syntheses of new ball-type Co(II) phthalocyanines containing 4,4 0-(9H-fluorene-9,9-diyl)diphenol substituents at non-peripheral (complex 6) and peripheral (complex 7) positions are presented. These complexes were characterized by UV-Vis, FT-IR, mass spectroscopy and electrochemical methods. Both complexes exhibit metal and ring based redox processes, typical of cobalt phthalocyanine complexes. For 6, the metal based reduction was observed at À0.46 V followed by a ring based reduction at À1.40 V. The metal oxidation for 6 was observed at +0.16 V and the ring based oxidation at +1.05 V. For 7, reductions are easier but the oxidations are more difficult. The metal based reduction for 7 was observed at À0.38 V followed by a ring based reduction at À1.03 V. The metal oxidation for 7 was observed at +0.20 V and the ring based oxidation at +1.35 V.
2013
Abstract: Neutral tridentate N 2 O complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been synthesized using the 1-phenyl-2,3-dimethyl-4(2-iminomethylbenzylidene)-pyrozol-5-(α-imino)-indole-3-propionic acid (H 2 L). All the complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility data, IR, 1 H-NMR, UV-Vis, FAB-Mass and EPR spectral studies. The physicochemical studies and spectral data indicate that the ligand acts as a divalent tridentate chelating agent. All the complexes have the general composition [ML 2 ] (M= Cu(II), Ni(II), Co(II) and Zn(II); L = Schiff base). The IR, UV-Vis., magnetic susceptibility measurements and EPR spectral data of the complexes suggest that all the complexes are octahedral geometry. The lower conductivity data confirm the non-electrolytic nature of the complexes. The effect of redox potential on Cu(II) and Ni(II) ions by the ligand environment is studied by cyclic voltammetric measurements. The Schiff base and its...