Phthalocyanine-based molecular metals

Phthalocyanine-based molecular metals and conductive polymers have been prepared and investigated by 13C solid state NMR. Among others, Ge serves as a central atom219,220. However, no discussion of a special role of the metal is presented in this work. 

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. 

Phthalocyanine-based dyes are especially useful for CD-R, as the chromophore absorption band falls in the desirable spectral range, and they are noted for excellent photostability. Unlike cyanine dyes, phthalocyanines tend to have very poor solubility, particularly in solvents such as alcohols and aliphatic hydrocarbons (which do not attack polycarbonate and are therefore used for spin coating). Therefore, the main barrier to the wider use of these dyes is the relatively high cost of synthesizing soluble derivatives. Suitable modifications to the Pc core which have been developed, notably by Mitsui Toatsu, are shown in Scheme 7. The bulky R groups reduce undesirable molecular association (which in turn lower the extinction coefficient and hence reflectivity), whereas partial bromination allows fine-tuning of the film absorbance and reflectivity. The metal atom influences the position of the absorption band, the photostability, and the efficiency of the radiationless transition from the excited state.199 This material is marketed by Ciba as Supergreen.204... 

Figure 4 shows the molecular structures of the monomeric phthalocyanines used as the active layer of p-type OFET devices, and Table 1 organizes the performance of these phthalocyanine-based OFETs. As can be seen, unsubstituted metal-free phthalocyanine and its metal complexes, axial substituted metal phthalocyaines, and peripheral tetra-substituted phthalocyanines all can work as p-type semiconductors for OFET devices. Most of the semiconductors composed of peripheral unsubstituted and axial substituted phthalocyanine derivatives are prepared through vacuum deposition method with a few exceptions being made of corresponding single... 

Anode contacts to hole transporting molecular layers were discussed briefly in Section 9.3.2. To reiterate, it is often found that metal phthalocyanine compounds effectively mediate the injection of holes from ITO into hole transport layers. (One could also say oxidation of carbocations in the HTL with net transfer of an electron from the HTL into the ITO.) Some experiments have suggested that multiple layers of phthalocyanines based on different metals, and hence having different HOMO state energies, can further reduce the injection barrier. The basic method in use in these cases is to provide a staircase of small barriers up which a hole can climb more easily than would be the case for a single large step. The low mobility of holes in the organic interlayers comes in handy here as it reduces the rate at which holes return to the contact. 

A mild aerobic palladium-catalyzed 1,4-diacetoxylation of conjugated dienes has been developed and is based on a multistep electron transfer46. The hydroquinone produced in each cycle of the palladium-catalyzed oxidation is reoxidized by air or molecular oxygen. The latter reoxidation requires a metal macrocycle as catalyst. In the aerobic process there are no side products formed except water, and the stoichiometry of the reaction is given in equation 19. Thus 1,3-cyclohexadiene is oxidized by molecular oxygen to diacetate 39 with the aid of the triple catalytic system Pd(II)—BQ—MLm where MLm is a metal macrocyclic complex such as cobalt tetraphenylporphyrin (Co(TPP)), cobalt salophen (Co(Salophen) or iron phthalocyanine (Fe(Pc)). The principle of this biomimetic aerobic oxidation is outlined in Scheme 8. 

Phthalocyanines and metal phthalocyanines which require high probe (and often high source) temperatures (>350°C) in conventional El mass spectrometry, readily give molecular ions as the base peak 65b) in FD spectra and minimal fragmentation occurs, providing a rapid method for the qualitative examination of mixtures of phthalocyanines. 

The use of heterogeneous catalysts in the synthesis of urethanes from aliphatic and aromatic amines, C02 and alkyl halides has been explored only recently. Titanosilicate molecular sieves [60a], metal phthalocyanine complexes encapsulated in zeolite-Y [60a], beta-zeolites and mesoporous silica (MCM-41) containing ammonium cations as the templates [60b, c], and adenine-modified Ti-SBA-15 [60d, e] each function as effective catalysts, even without any additional base. 

Non-linear optics in molecular materials has long been restricted to the investigation of organic chromophores. Most of the tin-based coordination compounds have been proposed only recently. Additionally, heavy atoms, such as tin, have also been used to enhance the optical-limiting response of metal phthalocyanines." Although this property derives from the cubic (a E ) NLO response, and falls outside the scope of the present review, it provides additional insights suggesting that tin-based coordination compounds could deserve more attention in the search for future NLO chromophores. 

In this review, we explain the SAC-CI applications to molecular spectroscopy with some examples. In Section 2, we briefly explain the theoretical and computational aspects of the SAC-CI method. Then, we show some SAC-CI applications to molecular spectroscopy the excitation and ionization spectra of tt-conjugated organic molecules (Section 3), collision-induced absorption spectra of van der Waals complex (Section 4), excitation spectra and NMR chemical shifts of transition metal complexes (Section 5), photofragmentation reaction of Ni(CO)4 (Section 6), absorption spectrum of free-base phthalocyanine (FBPc) and bacterial photosynthetic reaction center... 

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