Synthesis, Structure, and Spectroscopic and Magnetic Properties of Mesomorphic Octakis(hexylthio)-Substituted Phthalocyanine Rare-Earth Metal Sandwich Complexes

The syntheses of new bis[octakis(hexylthio)phthalocyaninato] rare-earth metal(III) double-decker complexes [(C6S)8Pc]2M (M = GdIII, DyIII, and SmIII) (2−4, respectively) are described. These compounds are very soluble in most
common organic solvents. They have been fully characterized using elemental analysis, infrared, UV−vis spectroscopy,
and mass spectrometry. The crystal structures of compounds 2−4 have been determined by X-ray diffraction on
a single crystal. They are isostructural and crystallize in the monoclinic space group (space group C2/c). Their
lattice constants have been determined in the following order:  (2) a = 31.629(4) Å, b = 32.861(4) Å, c = 20.482(2) Å, β = 126.922(2)°, V = 17019(3) Å3; (3) a = 31.595(2) Å, b = 32.816(2) Å, c = 20.481(1) Å, β = 127.005(1)°, V = 16958(2) Å3; (4) a = 31.563(2) Å, b = 32.796(2) Å, c = 20.481(1) Å, β = 127.032°, V = 16924(2)
Å3. The magnetic properties of compounds 2−4 were studied, and it was revealed that the lanthanide ions and the
radical delocalized on the two phthalocyanine rings are weakly interacting. The mesogenic properties of these new
materials were studied by differential scanning calorimetry and optical microscopy. These phthalocyanine derivatives
form columnar-hexagonal (Colh) mesophases. Thin films of bis[octakis(hexylthio)phthalocyaninato] rare-earth metal(III) double-decker complexes (2−4) were prepared by a spin-coating technique. Thermally induced molecular
reorganization within films of bis[octakis(hexylthio)phthalocyaninato] rare-earth metal(III) double-decker complexes
(2−4) was studied by the methods of ellipsometry, UV−vis absorption spectroscopy, and atomic force microscopy.
Heat treatment produces molecular ordering, which is believed to be due to stacking interaction between neighboring
phthalocyanine moieties.