Subphthalocyanine chloro-substituted

The chloro group on the central boron atom of a chloroboron subphthalocyanine may be substituted by a phenyl or hydroxy group. The latter product can be further transformed into an ether.68... 

A single crystal X-ray diffraction analysis has been carried out on both the chloro- and the phenyl-substituted subphthalocyanines 2.284 and 2.287 (Figures 2.3.2 and 2.3.3). These analyses served to show that subphthalocyanines lie in a bowl-shaped conformation. This is, of course, very different from the near-planar conformation of the parent phthalocyanines. Presumably, this bowl-shaped structure accounts, in part, for the decreased molar absorptivities of the subphthalocyanines relative to their phthalocyanine parents . Nevertheless, despite the non-planar nature of these macrocycles, the subphthalocyanines are capable of supporting an induced diamagnetic ring current (as judged by NMR spectroscopy). Thus, they may appropriately be considered as being aromatic. 

The subphthalocyanines (SubPes the trimeric homologues of tetrameric Pcs) have been prepared in the presence of boron(III) as template. No other metal ions controlling the formation of SubPc have been found so far. Originally, the unsubstituted SubPes would have been synthesised by the reaction of phthalonitrile with BF3 or BCI3 at 240°C in 1-chloronaphthalene as solvent in 20-40% yield (Eq. 2.248) [492]. The products are normally contaminated by halogen-substituted subphthalocyanines and their separation is tedious. The structure of the chloro derivative is available [493]. 

Among subphthalocyanines with flnoroalkyl groups dodecatrifluoroethoxy substituted derivatives are known [114], The chloro derivative [(Cl)BSubPc(C)CH2CF3)i2] 205 was obtained by a standard cyclotrimerization of 3,4,5,6-tetrakis(2,2,2-trifluoroethoxy) phthalonitrile 50a in the presence of BCI3 inp-xylene (3 h, reflux, 32 %) (Scheme 54) and its X-ray aystal structure was established (Fig. 14). 

Claessens CG, Gonzalez-Rodnguez D, del Rey B, Torres T, Mark G, Schuchmann HP, von Sonntag C, MacDonald IG, Nohr RS (2003) Highly efficient synthesis of chloro- and phenoxy-substituted subphthalocyanines. Eur 1 Org Chem 2003 2547-2551... 

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