Water-soluble tetraresorcinolporphyrins with eight ω-pyridinium alkyl chains (octopusporphyrins) formed fluorescent and nonfluorescent monolayer assemblies by anion exchange of the headgroups. Electron microscopy of the evaporated solution of the octopusporphyrin having 11-pyridinium-undecanoyl side chains (1) with sodium perchlorate showed planar sheets. The uniform thickness of the layer was 4.0 ± 0.5 nm, corresponding to monomolecular platelets. An exciton calculation on the basis of the red shift of the Soret band (6 nm) is consistent with a two-dimensional arrangement with porphyrin separations of 25.6 and 17.4 Å in the x and y directions, respectively. Organic dianions such as anthraquinone-2,6-disulfonate (AQDS2-) were more effective than perchlorates or iodides for aggregate formation. Arrays of a 1:3 complex of 1/AQDS2- produced a curvature to yield nonfluorescent vesicles. The introduction of dimethyl groups at the bottom of the alkyl chains (octopusporphyrin 2) did not lead to enhanced aggregation, while the octopusporphyrin with long 2,2-dimethyl-C20-pyridinium chains (3) formed fluorescent fibers without assistance of special anions. The electron-transfer reactions of the 1 platelets with perchlorates, in which the relative fluorescence intensity was 30% of the monomer, were investigated. External addition of negatively charged electron acceptors, 1,2-naphthoquinone-4-sulfonate (NQS-) and anthraquinone-2-sulfonate (AQS-), led to partial quenching of the fluorescence of the central porphyrin layer. In both cases, the corresponding Stern−Volmer plots showed plateaus at sufficiently high concentration of the quinones. The results have been evaluated using equations derived for this special case of dynamic quenching by an electrostatically bound quencher. Binding constants of 3.4 × 104 and 1.7 × 105 M-1 and electron-transfer constants of 5 × 109 and 1.3 × 109 s-1 have been calculated for NQS- and AQS-, respectively.

Amphiphilic tetraphenylporphyrinato-metal (Zn(II), Fe(II)) derivatives with four alkylphosphocholine chains and an intramolecular coordinated axial imidazole (lipidporphyrins) produced stable colloidal solutions in water. Electron microscopy showed rodlike fibers with a uniform thickness of 10 nm, which corresponds to a double length of lipidporphyrin. The obtained fibers had some micellar characteristics and were sensitive to neither addition of electrolyte (for example, NaCl) nor change in pH. Scanning force microscopy (SFM) revealed evaporated fibers with a height of 2.8 nm on graphite. In the center of the fiber, there is probably a tetragonal tube constructed by densely packed porphyrin planes. The red shift in the broadened Soret band absorption by exciton interaction and the photophysical properties of the Zn(II) complex fibers suggested the formation of porphyrin J-aggregates. Furthermore, the first SFM images of the porphyrin fibers under liquid conditions are given. A Benesi-Hildebrand analysis revealed that the unit aggregate number for the Zn(II) complex was four, supporting a tetramer repeating structure. Fe(II) complex fibers, on the other hand, produced a kinetically stable O2 adduct reversibly at 25 °C. The coordination structures of the axial imidazole and O2 molecule in the Fe(II) complex have been clarified by resonance Raman spectroscopy. The O2-binding equilibrium and kinetic parameters were also evaluated.

The title compound is prepared as a higher homologue in an extensively conjugated series of TCNQ (7,7,8,8tetracyanoquinodimethane) and TNAP (9,9,10,1O-tetracyano-2,6-naphthoquinodimethane); its complexes with TTT (tetrathiatetracene) and HMTTeF (hexamethylenetetratellurafulvalene) are electrically highly conductive.

Photoirradiation into the LMCT band (λmax: 362 nm) of self-assembled amphiphilic tetraphenylporphyrinato-iron(III) (lipidporphyrinato-iron(III)) chloride with hyaluronic acid leads to reduction of the central ferric ion in saline solution (pH 7.4, 25 °C); the obtained lipidporphyrinato-iron(II) can reversibly bind and release dioxygen.

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