The photo-physical and optical power limiting (OPL) properties of several new thiophenyl-containing arylalkynyl
Pt(II) complexes with longer arylalkynyl groups, named ATP3, ATP4, ATP6 and ATP7 were studied.
Thiophene units were introduced into the structure as an attempt to modify photo-physical properties and OPL
capability. The new compounds have their thiophene rings either close to the Pt-atom (ATP7), in the middle of
the chain (ATP3), or at the terminal end (ATP4). The measurement results were compared with those of the
earlier studied PE3 compound. ATP6 is similar to ATP4, but with methoxy groups in the arylalkynyl ligands.
Just as PE3, all thiophenyl derivatives showed large intersystem crossing capabilities and triplet phosphorescence,
thus having the potential of large nonlinear absorption and good OPL performance. All compounds
are characterized by absorption and emission spectra, quantum yield, luminescence decay (fluorescence and
phosphorescence) and two-photon absorption capabilities at 780 nm, and compared to the properties of the
PE3 compound. Also analogous triazole-containing compounds, abbreviated Z1, Z2 and Z3, were studied in
the same way, and compared to the earlier studied Pt1-G1 compound. The OPL performance of all compounds
were measured, and clamping levels of approximately 2.5 to 5 μJ pulse energy from 30 mM (ATP) and 50 mM
(triazole) concentration samples were found. All compounds possess high transmission in the visible region and
fluorescence quantum yields in the order of 10−2 (ATP) and 10−3 (triazoles).