Modulation of the structures and properties of bidipyrrin zinc complexes by introducing terminal alpha-methoxy groups

• A bidipyrrin nickel complex was synthesized in a high yield by oxidatively coupling between the ligands in the corresponding 2:1 (L:M) type of dipyrrin nickel complex, and further demetallation afforded the free bidipyrrin ligand. Interestingly, when treating the bidipyrrin nickel complex or the free bidipyrrin with FeCl3 in CH2Cl2/MeOH, the symmetric di-alpha-methoxy bidipyrrin could be synthesized in a high yield, with two methoxy groups attached to the terminal pyrrolic alpha-positions. Moreover, the coordination of the unsubstituted and disubstituted bidipyrrins with Zn(OAc)(2),2H(2)O afforded two similar M2L2 type of bidipyrrin helical complexes with different ligand conformations and different Zn center dot center dot center dot Zn distances of 5.353 and 3.357 angstrom, respectively. The difference in the conformations may be related to the electrostatic repulsions between the methoxy substituents. These results indicate that the dyes based on helical bidipyrrin zinc complexes with tunable structures and photophysical properties may be developed simply by modulating the terminal alpha-substituents.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

Bidipyrrins

alpha-Alkoxy bidipyrrins

Helical complexes

Conformations

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