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Serendipity has been a major player in most dye discoveries, and phthalocyanines are no exception. The true account of their discovery in 1928 is given using information provided by one of the individuals involved (Ron Greig). One of the inventors, Drescher, after making a key observation as to the nature of the insoluble blue impurity formed in the routine manufacture of phthalimide from phthalic anhydride, was killed weeks later when, on his beloved Sunbeam motorcycle, he had a head-on collision with a steamroller on his way to work. The unique properties of phthalocyanine dyes and pigments make them the colorant of choice for most blue and green colours. Thus most blue and green cars, including sports cars, are coloured by phthalocyanine pigments. In addition to these traditional uses, phthalocyanines are also finding extensive use in modern hi-tech areas. They are used for their colour as, for example, cyan dyes in ink jet printing, and in colourless applications such as infrared absorbers in security. The discovery, traditional and hitech applications of phthalocyanines are described in detail in this paper.

A new dyad 9(ZnP-P) has been synthesized linking 5,15-bis(4-carboxyphenyl)-10,20-bis(4-nitrophenyl) porphyrin 4(P) and Zn(II) 5-(4-aminophenyl)-10,15,20-tris(4-methoxylphenyl) porphyrin 8(ZnP) by an amide bond. The structural moieties of dyad 9(ZnP-P) present both different singlet state energy and redox properties. Dyad 9 was designed to improve the intramolecular electron transfer capacity. The ZnP moiety bears electron-donating methoxy groups and a zinc ion, while the other porphyrin structure, P, is substituted by electron-withdrawing nitro groups. On the other hand, structure P bears a carboxylic acid group, which is able to benefit from the orientation of dyad 9 adsorbed on the SnO₂ electrode. Absorption spectroscopic studies indicated only a very weak interaction between the chromophores in the ground state. The fluorescence analysis shows that both porphyrin moieties in dyad 9 are strongly quenched and that the quenching increases in a polar solvent. The ZnP moiety acts like an antenna for porphyrin P, but, singlet-singlet energy transfer is not complete. Thermodynamically, dyad 9 presents a high capacity to form the photoinduced charge-separated state, ZnP^·+-P^·-. Dyad 9 sensitizes the SnO₂ electrode and the photocurrent action spectrum closely matches the absorption spectrum, which confirms that light absorption by dyad is the initial step in the charge transfer mechanism. The photocurrent efficiency of dyad 9 is considerably higher than those of porphyrin monomers used as models of ZnP and P structures. Two processes may be contributing to enhance the charge injection efficiency in dyad 9; one involves an antenna effect that produces energy transfer from ZnP to P and the other includes electron transfer from the ZnP moiety to the photooxidizable free-base P. This dyad design, with P in direct contact with the substrate through the free carboxylic acid group, is a promising architecture of organic material for spectral sensitization of semiconductor solar cells.

Novel complexes of cobalt(II) with sulfonated derivatives of phthalocyanines are synthesized. The influence of the sulfonated group's number in peripheral substituent on solubility of macrocycle and ability to form ordered structures in solution is showed. Transition from H-aggregates to monomeric phthalocyanine structures and sandwich-type dimers was found during formation of metallophthalocyanine complexes with 1,4-diazabicyclo[2.2.2]octane. The catalytic activity of metallophthalocyanines was studied on the model of Merox process.

The use of adsorption capacity of porous and large-surface-area materials is an important approach to treat dye-containing effluents. In this study, the porous carbon nanocages (CNCs) were synthesized from the precursor of phenol in home-made chemical vapor deposition (CVD) setup at 600–1000^°C, and were convincingly characterized. The as-prepared CNCs are amorphous, porous and hollow, and have the size of 50–100nm in width, 100–200nm in length and several nm in thickness, causing to the large surface area of 800m²/g and pore volume of 1.63cm³/g. The growth of amorphous-like CNCs was related to the thermolysis species of phenol. Interestingly, each CNC has large volume hollow coelom and small opening (a typical ink bottle pore), being in favor of adsorption but in disfavor of desorption, thus it is very fit for acting as the adsorbent of dye. As expected, the products showed excellent adsorbility of rhodamine B when compared with the most used activated carbon having straight and slit pore structures, displaying broad application prospects in removing dye from wastewater.

In this work, we used the modified Hummers method to synthesize graphene oxide, and the redox reaction of FeCl${}_3\cdot 6$H₂O with the carboxyl group on the surface of acidified graphene was carried out to prepare magnetic nanoparticles modified on the surface of graphene (magnetic graphene nanocomposite). X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Vibrating Sample Magnetometer (VSM) and Brunauer–Emmett–Teller measurement (BET) analyses were used to characterize the nanocomposite properties. SEM and TEM images of the nanocomposite show that the magnetic nanoparticles are distributed on both sides of the graphene, and the magnetic nanoparticles diameter is between 100 and 150nm. The XRD pattern indicates that the magnetic nanoparticles are Fe₃O₄ nanoparticles. Based on the VSM, the nanocomposite exhibits a saturation magnetization value of 14.94$\mathrm{\text{emu}}\cdot {\mathrm{\text{g}}}^{-1}$. By BET measurement, the specific surface area of the nanocomposite is 26.54m${}^2\cdot {\mathrm{\text{g}}}^{-1}$, and the surface of the nanocomposite is highly porous. In the experiment of dyes adsorption, the adsorption efficiency in the solution was close to 100%. It can be applied in biomedical and environmental fields such as water purification owing to its high surface, magnetic attraction properties and good adsorption efficiency.