Naphthalocyanine Metal Complexes

From the Raman spectra and SERS on silver colloid of vanadyl-5,14,23,32-tetraphenyl-2,3-naphthalocyanine VOTPNPc it was deduced a short distance complex-surface interaction this was verified by the appearance of a band at about 216cm , previously assigned to a Ag-N binding this band is not observed in the free molecular system. 

With respect to the metal-adsorbate interaction it is of interest, for comparison with the experimental results, to develop theoretical calculations based on molecular models that involve the adsorbate molecules and a metal cluster. The INDO/1 semiempirical method has been proved to be very useful in the stmc-ture optimization and in the evaluation of the bond characteristics throughout the Wiberg index - ° The interaction of azamacrocycle complexes with simulated copper surfaces studied by the same method was performed - 

Theoretical calculations about the energetic of the adsorbate-substrate interaction for approximate molecular models of the azamacrocycle series mainly 

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Phthalocyanine (59) and naphthalocyanine (60) complexes appear to be highly active, and Zn-60 adducts have attracted commercial interest (259, 260). Many metal complexes of 56, 59 and 60 are very... 

Metal complexes of various porphyrins 47, phthalocyanines 48 and naphthalocyanines 49, with intense absorptions in the visible region of light, have also been covalently bound to macromolecular carriers. Early work in this field was reviewed in 1977 and 1983 [124,125], These reviews, for example, reported the fixation of metal-free and metal-containing protoporphyrin-IX, chlorophyll, mesoporphyrin-IX and substituted 5,10,15,20-tetraphenyl-porphyrins. The binding of substituted phthalocyanines to substituted polymers has also been reviewed [125,126] and covers mainly the binding of carboxylic or sulfonic acid-substituted phthalocyanines to polystyrene. 

Little work dealing with vibrational studies of the macrocycle-surface interaction have been published for naphthalocyanine and its metal complexes. One deals with the ZnNc complex for which the orientation onto different substrates has been inferred from IR reflection-absorption spectroscopy and other measurements three types of molecular orientations were assigned for the deposited thin films depending on NaCl, graphite and glass at 250 = C. The orientation of different metal complexes of naphthalocyanine was studied by X-ray... 

A class of compounds with a comparatively high thermal stability are unsaturated, sometimes aromatic metallomacrocycles, e.g. derivatives of tetraazaporphyrin (TAPHj) of which the most thoroughly investigated are the phthalocyaninatometal (PcM), the tetrabenzoporphyrinatometal (TBPM) complexes, the metal complexes of 1,2- and 2,3-naphthalocyanines (1,2- and 2,3-NcM), and the tetra(2,3-naphtho)porphyrins (2,3-TNPM) (Fig. 1). 

ABSTRACT. Bridged macrocyclic transition metal complexes using phthalo-cyanine and naphthalocyanine as macrocycles e.g. [PcML] with M = Fe, Ru Co and L = dib, tz, CN show good semi-conducting properties without external doping. The mechanism of the formation of the bridged macro-cyclic metal complexes is studied by H-NMR spectroscopy using the monomer PcFe(Me dib) . 

The phthalocyanines, naphthalocyanines, and certain of their metal derivatives (Figure 6.17) are infrared fluorophores. 61"64 As a class, they are exceptionally stable compounds, with copper (Cu) phthalocyanine (not a fluorophore) remaining intact above 300 °C in air. First used for textile dyeing in the last century and still widely used, there is a rich chemistry of phthalocyanines. Most derivatives can be made by prolonged heating of a phthalimide or phthalic acid derivative with a metal in powder or salt form at elevated temperature. Several derivatives absorb in the near-IR, and either fluoresce or phosphoresce. The electronic transitions of phthalocyanines are complex and have been extensively studied, at least in part because the symmetry of the molecule makes theoretical calculations of its spectroscopic behavior more tractable. Unsubstituted phthalocyanines and naphthalocyanines are, as a class, very insoluble in solvents other than, for instance, nitrobenzene. Sulfonated phthalocyanines are water soluble and exhibit spectra comparable to the parent derivative. Photolumines-cent phthalocyanines (Pcs) include SiPc, ZnPc, and PC itself. These compounds have been little used for practical infrared fluorometry to date however, Diatron Corpora-... 

Treatment of Lu(0Ac)3-nH20 with phthalonitrile in the presence of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU) in 1-hexanol gives the sandwich compound Lu(Pc)2 and the half-sandwich complex Lu(Pc)(0Ac)(H20)2 (De Cian et al. 1985). Both compounds were structurally characterized and the latter was believed to be an intermediate in the formation of the former complex. A solid-state reaction of Lu(OAc)3 and phthalonitrile may also lead to the formation of Lu(Pc)(OAc) and Lu(Pc)2, along with the metal-free phthalocyanine H2(Pc). The ratio of these products depends on the reaction temperature and reaction time (Clarisse andRiou 1987). The 1,2-naphthalocyanine analog Lu(l,2-Nc)(OAc) has recently been prepared in 56% yield by treating Lu(OAc)3 with Li2(l,2-Nc) in 1,2,4-trichlorobenzene (Guyon et al. 1998). 

The relative intensity ratio between selected bands measured in IRRAS suggested that in the case of the naphthalocyanine complex the compound is oriented with the naphthalocyanine moiety plane parallel to the copper surface the VO and the phenyl groups in both complexes are oriented perpendicular to the macrocycles rings, with the oxygen atom opposed to the metallic surface. Therefore, it exist a preferential molecular orientation of the molecules deposited onto the copper surface. 

The SERS spectral data obtained on colloidal Ag as well as Ag island films indicate a weak macrocycle interaction and small structural modifications of the naphthalocyanine complex on the surface. An energy transfer mechanism contribution to the observed enhancement was proposed. The whole spectral data point that the naphthalocyanine complex is oriented with the naphthalocyanine plane face-on to the surface. In both vanadylnaphthalocyanine and vanadylpor-phine tetraphenyl substituted complexes the vanadyl group is perpendicular to the coordination site and opposed to the surface. In both complexes the phenyl substituents, oriented perpendicular to the macrocycle plane, are responsible of the weak adsorbate-substrate interaction. Several different experimental conditions such as scanning speed, laser power and excitation lines wavelengths, concentration and metal surfaces were intended to obtain SERS of the porphine complex without success this was interpreted in terms that the complex has no interaction with the surface. Thus, it was concluded that the extension of the whole r-system plays a significant role in the mechanism involving the spectral enhancement by surface effect. 

The spectral results and calculations performed by Saavedra et indicate that the interaction of the macrocycle sub-2,3-boronnaphthalocyanine chlorine (subBClNPc) with different metallic surfaces is rather weak. The interaction with the surfaces takes place through the chlorine atom. This situation is mainly due to the cone-shape structure of subBClNPc, in contrast to other slightly warped naphthalocyanine complexes or planar azabipiridyl complexes, where the interaction with metal surfaces occurs through the whole tt electronic system " . Such an orientation leads to slight differences in the band intensities on varying the incidence angle in RAIRS experiments (Figure 14.32). 

One of the most relevant evidences of a relatively significant interaction between the macrocycle complex and the metal surface is the appearance of a vibrational band. This kind of metal-ligand bands is better observed in the Raman spectrum below 500cm . Bands corresponding to the adsorbate-substrate interaction were observed in azabipiridyl, phthalocyanines, naphthalocyanines and... 

Formally, tetravalent cerium is long known to form stable sandwich complexes with tetrapyrrole-type macrocyclic ligands such as porphyrines, phthalocyanines, and 2,3,-naphthalocyanines (Scheme 12). For the rare earth sandwich complex series, virtually all the neutral complexes can be formulated as Ln° (ring-1 ) (ring-2 ), in which a trivalent rare earth metal center is sandwiched between a... 

The functionalization of fullerenes with nitrogenated groups such as pyridine and imidazole allows such fullerene derivatives to coordinate with metallated porphyrines, phthalocyanines (Pc), and naphthalocyanines (Nc) (Figure 2.15). The structure of a noncovalently linked ZnTPP to a Cso derivative has been studied with x-ray diffraction, bringing more information regarding conformation and atom distances of the complex. ... 

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