Crystals, phthalocyanine, molecular

Janczak, J. and Kubiak, R. (1992). Crystal and molecular structures of metal-free phthalocyanines, 1,2-dicyanobenzene tetramers. II. a Form. J. Alloys Compd, 190, 121. [270]... 

Yanagi, H., Douko, S., Ueda, Y., Ashida, M., and Wdhrle, D. (1992) Improvement of photoelectrochemical properties of chloroaluminum phthalocyanine thin films by controlled crystallization and molecular orientation.. Phys. 

Molecular crystals Phthalocyanines [PbPc, LuPc, LiPc, FePc, CuPc, NiPc, (PcAIF) , (PcGaF), etc.] Gases, vapors, ions (sensing materials, membranes)... 

The elucidation of the structure of the phthalocyanines followed some pioneering research into the chemistry of the system by Linstead of Imperial College, University of London. The structure that we now recognise was first proposed from the results of analysis of a number of metal phthalocyanines, which provided the molecular formulae, and from an investigation of the products from degradation studies. Finally, Robertson confirmed the structure as a result of one of the classical applications of single crystal X-ray crystallography. 

These results illustrate that electrochemical techniques can be employed to synthesize a vast range of [Si(Pc)0]n-based molecular metals/conductive polymers with wide tunability in optical, magnetic, and electrical properties. Moreover, the structurally well-defined and well-ordered character of the polymer crystal structure offers the opportunity to explore structure/electro-chemical/collective properties and relationships to a depth not possible for most other conductive polymer systems. On a practical note, the present study helps to define those parameters crucial to the fabrication, from cheap, robust phthalocyanines, of efficient energy storage devices. 

Abstract In this chapter, recent progress in the synthesis, crystal structures and physical properties of monomeric phthalocyanines (Pcs) is summarized and analysed. The strategies for synthesis and modification of Pcs include axial coordination of central metal ions, peripheral substitution of Pc rings and the ionization of Pcs. The crystal structures of various typical Pcs, especially the effects of different synthetic and modification strategies on the supramolecular assemblies of Pcs via %—% interactions between Pc rings, are discussed in detail. Finally, the UV-vis spectroscopic, conducting, magnetic and catalytic properties of some Pcs with crystal structures are presented briefly, and the correlations between various properties and the molecular structure discussed. 

Three dimensional X-ray diffraction analysis has been employed to elucidate the molecular and crystal structure of Copper Phthalocyanine Blue ((3-modifica-tion). In all modifications, the planar and almost square phthalocyanine molecules are arranged like rolls of coins, i.e., in one dimensional stacks. The modifications vary only in terms of how these stacks are arranged relative to each other. One important aspect is the angle between staple axis and molecular plane. The a-phase features an angle of 24.7°, while the stacks in the -modification deviate by as much as 45.8° [13]. 

The first structural report on a phthalocyanine complex concerned [Ni(pc)J (Table 110 I).2878 In the crystal lattice of this compound the square planar macrocycles are arrayed in slipped stacks such that the distance between the molecular planes along the perpendicular direction is 388 pm. [Ni(pc)] may be prepared by a variety of methods 2873,2871 2880 a convenient one is heating a foil of elemental nickel in o-cyanobenzamide at 270 °C (Scheme 60).2881 [Ni(pc)] is insoluble in the most common organic solvents, but soluble in concentrated sulfuric acid from which it is reprecipitated unchanged upon dilution. This complex is thermally very stable and may be sublimed in vacuo. The reduction of [Ni(pc)] can be accomplished by chemical or electrochemical methods and results in ligand-based reduced anions [Ni(pc)]" ( = 1, 2). Analogously, the electrochemical oxidation results in the oxidized ligand. 3... 

The macrocyclic phthalocyanine ligand will form a complex Pt(phthalocyanine).1106 The crystal structure shows two polymorphs present because of molecular packing.1107 The platinum is in a square planar coordination geometry with a mean Pt—N distance of 1.98 A. The complex can be partially oxidized with iodine to give conducting mixed valence solids.1108 Eighteen fundamental and overtone combination bands are observed in the resonance Raman spectrum of platinum phthalocyanine, and from this data the symmetry of the excited singlets are found to be Dy.. Qlv or D2.1109... 

With Z = 2, the iron(II) phthalocyanine molecule occupies a 1 site, and its molecular and crystal stmctures are shown in Fig. 9.6.6. 

Molecular complexes, such as the complex formed between poly(N-vinylcaibazole) and 2,4,7-trinitro-9-fluorenone, and dye-polymer aggregates were widely used as generation materials in many early applications. Since these materials are not infrared sensitive, there has been increasing emphasis on pigments. The more widely studied are various azo, phthalocyanine, squaraine, and peiylene diimide derivatives. A common feature of all of these materials is that they are polymorphic and exist in many different crystal forms. The properties are thus very sensitive to the conditions used in their preparation. Further, the sensitivity of these materials is strongly field dependent as well as dependent on the transport material. For a review of generation materials, see Law (1993). 

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