Synthesis, structural and conformational analysis and chemical properties of phthalocyaninatometal complexes

Article abstract of DOI:10.1016/S0022-2860(97)00309-8

Syntheses of the phthalocyaninatometal complexes were performed and the crystal and molecular structures were determined by single-crystal X-ray diffraction analysis. The general formulas of these Pc dye compounds are -[Si(Pc)OSiR₂/¹R²SiR₂/¹O](n)-and Si(Pc)(OSiR¹R²R³)₂: -[Si(Pc)OSi(CH₃)₂(CH₂)₇Si(CH₃)₂O](n)- (1), Si(Pc)[OSi(C₆H₁₃)₃]₂ (2) Si(Pc)[OSiC₈H₁₇(CH₃)₂]₂ (3) and Si(Pc)[OSiCH₃C₁₂H₂₅CH₃]₂ (4). These Pc dye derivatives were prepared by refluxing a mixture of Si(Pc)(OH)₂ and SiR¹R²R³Cl in pyridine, followed by cooling the mixture slowly and then drying the resulting precipitates. For 1-3, the Pc skeleton and the oxo-bridged substituentes are coplanar. The dihedral angle between the mean planes of the Pc skeleton and two single-atom Si(me) [Si(me)-O-Si(pc)-O-Si(me)] is nearly at right angles. The Si(pc)-O bonds are shorter than the Si(pc)-N bonds and the Si(me)-O bonds are shorter than the Si(pc)-O bonds. For 1, the Pc microcyclic rings are related by a center of symmetry at the center of the O₁-Si₁-O₂ bonds. The chemical formula of a mononer is C₄₃H₄₂N₈O₂Si₃ (C₂₅H₂₈N₅O₂Si₃ in crystallographic symmetry) and the polymer is built up by the addition polymerization of the monomers. The polymer chain is constructed at the siloxy group along the a axis. Two hexyl groups of two siloxy side groups for 2 have the same direction, but one hexyl extends in the opposite direction. For 3, two methyl groups and one octyl group extend in the opposite direction. We applied Pc dyes 2-4, mixed with a polymer for the control of the aggregation state to CD-R and DVD-R recording systems. The aggregation state of the recording layer is controlled by choosing the set of axial substituents R¹-R³. The interactions of Pc dyes with polymers are dependant upon the length of axial substituents. We achieved the best writing contrast and the highest stability with the mixed PC dye 4. The conformation of axial substituents is very important for the ability of the dye aggregation and the capability to control the aggregation state.