Conductive polymeric Cu(II) tetrakis(3‐methoxy‐4‐hydroxyphenyl) porphyrin as a photosensitizer in a photoelectrochemical Cell

Abstract

Communications the long-axis rotation is more hindered and leads to a higher spontaneous polarization although its molecular dipole moment is smaller (see Table I).These results show that the asymmetry of the angular distribution of the mesogens can be increased by bulky lateral substituents. Therefore, not only the dipole moments but also the bulkiness of the lateral substituents should be increased in order to obtain materials of high spontaneous polarization ExperimentalThe synthesis of the chiral acids 2.4 and 6 and the corresponding polysiloxanes 7,9 and 11 are described in a previous paper [5]. Preparation of the axial-chiral 4-methylcyclohexylidene acetic acid 3 and the resolution of thc racemate is published elsewhere [12, 141.The chiral3-bromo-4-((S)-(l)-methylheptyloxy)-benzoic acid 5 was prepared in two steps according to the procedure of a Mitsunobu-reaction [I 51. To a solution of 3-bromobenzoic acid ethyl ester (3.5 g, 0.014 mol), (R)-2-octanol (2.18 g, 0.017 mol) and triphenylphosphine (5.5 g, 0.021 mol) in 70 mL dry cther at 0 C were added dropwise 3.7 g (0.021 mol) azodicarboxylic acid diethyl ester and the mixture stirred overnight at room temperature. Evaporation of the solvent, saponification of the ester with 3 g NaOH in ethanol/water (1.1) and acidification with 6 11 HCI gave the raw material. Flash-chromatography (petrolether/ethyl acetate 3: 1) leads to the pure 3-bromo-4-((S)-(l)-methylhep-ty1oxy)-benroic acid 5 (yield: 43%, [a]'" = f35.3". nz" =1.5450).The polysiloxanes 8 and 10 were prepared according to a polymer analogous esterification [5]. In a typical run 0.25 g (0.63 mmol) of polymer 1, 0.52 g (1.57 mmol) of the desired chiral acid and 0.01 5 g 4-(dimethylamino)pyridine (DMAP) were dissolved in 10 mL dry THF/CH,CI, and cooled to 0°C. Then 0.32 g (1.57 mmol) dicyclocarbodiimide (DCC) were added and the solution was stirred overnight and precipitated twice from methanol (polymer 10; yield: 77%: = +9.8' (c = 0.51 in CHCI,); M,;,, = 24000; polmyer 8; yield: 83%; [&' = +28.7' (c = 2 in CHCI,); M,,, = 23000). All analytical data were in agreement with the proposed structure.

Hole Mobility in Porphyrin- and Porphyrin-Fullerene Electropolymers

“…The films absorb strongly in the visible and are of potential utility in solar energy conversion, sensors and related areas. There are a number of reports in the literature of electropolymerization of porphyrins on electrodes. − However, polymers 1 and 2 differ significantly in structure from those produced previously. For example, in one widely studied class of polymers, the polymer chain is a substituted polyaniline, and the porphyrin macrocycles are present as pendant groups. ,,,, Similarly, polymerization of vinyl groups ,, and pyrroles , with porphyrins as pendant substituents has been reported.…”

“…For example, in one widely studied class of polymers, the polymer chain is a substituted polyaniline, and the porphyrin macrocycles are present as pendant groups. ,,,, Similarly, polymerization of vinyl groups ,, and pyrroles , with porphyrins as pendant substituents has been reported. Porphyrins polymerized via linkage of two meso-aryl groups bearing amino or hydroxyl ,, groups are also known. In none of these polymers is there a strong conjugated, conducting path that includes the porphyrin macrocycle.…”

“…3,9,10,14,17 Similarly, polymerization of vinyl groups 4,11,12 and pyrroles 4,18 with porphyrins as pendant substituents has been reported. Porphyrins polymerized via linkage of two meso-aryl groups bearing amino 16 or hydroxyl 4,13,15 groups are also known. In none of these polymers is there a strong conjugated, conducting path that includes the porphyrin macrocycle.…”