DITHIACROWN ETHER-SUBSTITUTED PORPHYRAZINES - SYNTHESIS, SINGLE-CRYSTAL STRUCTURE, AND CONTROL OF AGGREGATION IN SOLUTION BY COMPLEXATION OF TRANSITION-METAL IONS

The synthesis of novel magnesium, copper, and metal-free porphyrazines , peripherally substituted with dithia-7-crown-2 (MPz(7)), dithia-15-c rown-5 (MPz(15)), and dithia-18-crown-6 (MPz(18)) macrocycles is repor ted. These compounds are prepared starting from dicyanoethylene contai ning crown ethers 3, 2(1), and 2(2), respectively, which contain sulfu r as well as oxygen heteroatoms. The ''crowned'' porphyrazines bind si lver(I) and mercury(II) perchlorates. UV/vis spectroscopy and electron paramagnetic resonance measurements reveal that addition of the trans ition-metal ions leads to dimerization of the porphyrazine complexes. In the case of the dithia-18-crown-6-substituted porphyrazines, the di mers break up to form monomeric 6:1 guest-host complexes when more tha n 2 equiv of the metal ion is added. The single-crystal structures of the crown ether 2(2) and the porphyrazine MgPz(18) are presented. Comp ound C14H20N2O4S2 (2(2)) crystallizes in the monoclinic space group P2 (1)/c with a = 10.9310(13) Angstrom, b = 19.383(3) Angstrom, c = 8.697 6(14) Angstrom, beta = 108.898(11)degrees, V = 1743.5(5) Angstrom(3), and Z = 4. The structure refinement converged to R = 0.0366 and R(w) = 0.0504. Compound C56H82MgN8O17S8 (MgPz(18)) crystallizes in the tricl inic space group <P(1)over bar> with a = 9.584(3) Angstrom, b = 17.672 (2) Angstrom, c = 19.620(4) Angstrom, alpha = 84.904-(14)degrees, beta = 85.21(2)degrees, gamma = 89.29(2)degrees, V = 3298.4(13) Angstrom(3 ), and Z = 2. The structure refinement converged to R1 = 0.0839 and wR 2 = 0.2196. The electrical properties of H(2)Pz(18) have been studied by complex impedance spectroscopy. The bulk electrical conductivity of this compound is approximately 1 order of magnitude higher than that of the corresponding 18-crown-6 phthalocyanine.