In situ measurements of emission transition dipole moment of individual ordered microdomain of diprotonated tetraphenylporphine aggregate formed at dodecane/aqueous H2SO4 interface.

Rhombic-ordered microdomains of diprotonated 5,10,15,20-tetraphenylporphine aggregate, whose sizes were 10-200 microm, were formed at dodecane/aqueous H(2)SO(4) interfaces. The light excitation of their two absorption bands (410 and 473 nm for H- and J-bands, respectively) led to one fluorescence band at longer wavelength (723 nm). The direction of the emission transition dipole moment (mu(e)) of individual rhombic microdomains, determined with an in situ optical microscope and a linear polarizer, was almost parallel to the major axis, which was also almost parallel to the direction of the absorption transition dipole moment of their J-bands. Their absorption and emission transition scheme was proposed.