Synthesis, structures and two-photon pumped up-conversion lasing properties of two new organic salts

We have synthesized two new organic salts, trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium toluene-p-sulfonate (abbreviated as HMASPS) and trans-4-[p-(N-hydroxyethyl-N-ethylamino)styryl]-N-methylpyridinium toluene-p-sulfonate (abbreviated as HEASPS). X-Ray diffraction analyses reveal that HMASPS crystal belongs to the P2(1)/n space group, with water molecules co-crystallized in the crystal and forming the monohydrate with the formula of C17H21N2O+. C7H7O3S-. H2O, while HEASPS belongs to the P (1) over bar space group, with no solvent molecules. Pumped by a 1064 nm, 50 ps laser pulse at 2.02 mJ input energy, an up-conversion lasing of 0.169 mJ output energy can be obtained with 0.05 M HMASPS-DMF solution, and the output/input efficiency is 8.4%. A 0.05 M HEASPS-DMF solution exhibits a lasing efficiency of 9.1% with input and output energy of 1.90 mJ and 0.173 mJ respectively.