Vapor pressure of tetrasubstituted metal phthalocyanines bearing fluorine substituents in non-peripheral positions

In this paper, the temperature dependence of the saturated vapor pressure of fluorosubstituted phthalocyanines with substituents in non-peripheral positions of the macroring, viz. MPcF4-np, M=Cu, Fe, Co, VO, was investigated by the Knudsen effusion method with mass spectrometric registration of the gaseous phase composition. The standard thermodynamic parameters Delta H degrees T and Delta S degrees T of the sublimation process of these compounds were determined. The results were compared with the vapor pressure of the corresponding MPcF4-p analogs bearing F-substituents in the peripheral positions. It was shown that the volatility decreased in the order of VOPcF4-np > CoPcF4-np similar to CuPcF4-np similar to FePcF4-np > ZnPcF4-np, which correlated with the increase in their crystal lattice energy in the same order. The volatility of most MPcF4-np (M = Cu, Zn, Co, VO) was lower than that of MPcF4-p. The results were analyzed from the point of view of crystal packing and intermolecular interactions in the crystal.