Perfluorinated Subphthalocyanines

The structure of [ClBSubPcF ] was determined by X-ray diffraction study [100] (Fig. 7). [ClBSubPcFn] is well soluble in organic solvents, the solutions are stable in the dark, but tend to decompose in the presence of light due to weak B-Cl bond and long-lived triplet states [98, 99], So far BCI3 is the only boron derivative successfully used in the preparation of fluorinated subphthalocyanines. Reactions 

Perfluorination of subphthalocyanine macrocycle leads to a relatively small bathochromic shifts of the %-% absorption maxima in the UV and visible regions (from 300 to 560 nm for [ClBSubPc] to 310 and 570 nm for [ClBSubPcFij] in acetonitrile [98]), indicating that HOMO is slightly less stabilized than LUMO. Indeed, perfluorination shifts the 1st reduction potentials by ca 700 mV to the positive region ( 14 =-0.43 V vs. SCE in MeCN [98]). The irreversible oxidation for [(X) BSubPc] is observed only at ca. +1.5 V, at potentials by 500 mV more positive as compared to non-fluorinated species [98, 104]. [ClBSubPcF,2] exhibit the strong fluorescence in solution (emission maxima at 586 nm) and have high fluorescence quantum yield (( )=0.6) [98], which is comparable with the data for non-fluorinated species. 

Reaction of TFPN with BCI3 in the presence of other ori/io-dintriles leads to a mixture of [ClBSubPcF ] with another symmetrically substituted species and two low-symmetry octafluoro and tetrafluoro derivatives having symmetry lower than C y. 

The structure of mononaphthalene-fused derivative was established by X-ray crystallography (Fig. 8). The extension of the Jt-system by replacing of tetrafluoro-benzene fragments by naphthalene rings leads to increased red shift of the lowest n-% transition (g-band) from 573 nm in 176 to 617 and 640 nm in mononaphtho-and dinaphtho-fiised species 180 and 181, respectively. 

The lower 1 2 ratio gives 1 % of the dimers and along with [ClBSubPcF ] (26 %), octafluorophthalimide derivative 185 (16 %) and tetrafluorophthalimide (12 %) were isolated [104]. 

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Scheme 49 Synthesis of thiolane substituted perfluorinated subphthalocyanine...

Scheme 50 One-pot two-step procedure for preparation of axially substituted perfluorinated subphthalocyanines through the triflate derivative 194...

Abstract This chapter describes the synthesis of phthalocyanines, subphthalocyanines and porphyrazines bearing fluorine atoms and/or perfluorinated alkyl or aryl groups. Influence of fluorination of macrocycle on its physico-chemical properties and perspectives of application is also briefly considered. 

Among fluorinated derivatives perfluorinated boron subphthalocyanines, fused fluorinated subphthalocyanines with extended it-system and perfluorophenyl substituted boron subporphyrazines are known. 

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