Synthetic studies of substituted 2,3-naphthalocyanines

Synthesis and Characterization of Soluble Octaaryl‐ and Octaaryloxy‐Substituted Metal‐Naphthalocyanines

“…The measured molar extinction coefficients of 9a,b-11a,b in THF are high, which also indicates no aggregation at least at low concentrations (Ͻ 10 Ϫ5 ). The lg(ε) values for the Q-bands of V, Zn, and Mg compounds in THF are in the range of 5.57Ϫ5.66, similar to that seen in [(PhS) 8 NcZn] [4] and higher than those found for alkylthio-, alkyl-, and alkoxynaphthalocyanine complexes. [4,20] A change in the solvent from THF to toluene shifts the absorption bands bathochromically, by up to 10 nm for the Q-band (see Table 1).…”

“…Use of less pure 7 results in the formation of polar dark-brown byproducts, which usually stay at the top of the column during chromatography, but they may also substantially disturb the reaction, lowering the yield. Although the preparation of 6,7-diphenylthioor 6,7-dialkylthio-2,3-dicyanonaphthalene by treatment of 7 with thiolate ions, catalyzed by Cu 2 O, has already been described, [4] the above route for the preparation of 6,7-diaryloxy-substituted 2,3-dicyanonaphthalene (e.g., 8) is presented here for the first time.…”

“…The square-planar copper complex 13a is poorly soluble and strongly aggregated even in coordinating solvents, due to its weak ability to form penta-or hexacoordinate species. The presence of only four meta-trifluoromethylphenyl groups in positions 3(4), 12(13), 21 (22), and 30(31) does not solubilize naphtha- locyanines even in the case of the square-pyramidal complex [(m-CF 3 Ph) 4 NcVO] 14. The key point determining the solubilities of the prepared substituted naphthalocyanines is the presence of meta-substituted aryls in neighboring positions at the periphery of the macrocycle, resulting in their nonplanar arrangement relative to the Nc plane.…”

“…The solubility can be increased by introduction of peripheral substituents (mainly alkyl, alkylthio, or alkoxy) and/or axial ligands in their metal complexes. An additional effect that has to be reduced for better performance of Ncs and their metal complexes Ϫ in various nonlinear optical devices such as optical limiters, [3] for example Ϫ is their strong tendency to form aggregates in solution, [4,5] because of the strong van-derWaals interactions between different rings due to the mostly planar structures of the molecules and their extended conjugated π-electron systems. Introduction of bulky substituents at the peripheries of Nc macrocycles should prevent these cofacial interactions of the Nc molecules and thus increase the solubility of the compounds.…”

Tetra[6,7]quinoxalinoporphyrazines: The Effect of an Additional Benzene Ring on Photophysical and Photochemical Properties

“…Ncs are well known and widely investigated compounds. [13,14] 6,7-TQPs have been discovered only recently [15,16] because of the lack of reliable synthetic methods leading to their precursors. However, recent developments [17][18][19] in the synthesis of a key starting material 4,5-diaminophthalonitrile (1) will surely lead to more extensive exploration of this class of organic dyes.…”