Synthesis, Structural Analysis, and Chemical Properties of Phthalocyanine Derivatives. K. Okada¹, N. Sasa¹, K. Nakamura² and S. Okada³, ¹Ricoh R & D Center, Yokohama, Japan, ²Showa University, Tokyo, Japan, ³Science University of Tokyo, Tokyo, Japan

Syntheses of the metallophthalocyanic and oxo-bridged phthalocyanine (Pc) dye derivatives were performed and the crystal and molecular structures have been determined by single-crystal X-ray diffraction analysis. The general formula of these Pc derivatives is Si(Pc)(OSiR1R2R3)2: -[Si(Pc)(OSiCH3)2 C7H14]n- (1), Si(Pc)[OSi(C6H13)3]2 (2), Si(Pc)[OSiC8H17(CH3)2]2 (3) and Si(Pc)[OSiC12H25(CH3)2]2 (4). These Pc dye derivatives are 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.

The crystal and molecular structures of 1 to 3 have been determined by single-crystal X-ray diffraction analysis. The structures were solved by the application of direct methods. 1 Eight atoms of 1 were located on the special position (z=1/4). All computations were performed on an Compaq personal computer with a DS*SYSTEM3.1

The Pc skeletons of 1 to 3 and the oxo-bridged substituentes are coplanar. The dihedral angle between the mean planes of the Pc skeleton and two single-atom Sime [Sime-O-Sipc-O-Sime] is nearly at right angles. The Sipc-O bonds are shorter than the Sipc-N bonds, and the Sime-O bonds are shorter than the Sipc-O bonds. The polymer chain for 1 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. No readjustment of these siloxy groups is allowed. The crystalline conformations of 2 and 3 are exactly coincident with the potential energy minimum. The energy barriers have unifold patterns, are high and narrow due to steric repulsion caused by the Pc skeleton.

We applied Pc dyes, 2 to 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 to R3. The interactions of Pc dyes with polymers are dependant upon the length of axial substituents. We got 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.

[1] K. Okada and S. Okada, IUCr96, CGA17 Abstr. (1996) PS03.02.10, C-80.