A new molecular conductor PyH[Pd(dmit)2]2 (PyH=pyridinium, dmit=2-thioxo-1,3-dithiole-4,5-dithiolato) has been synthesized and structurally investigated. The room temperature conductivity at a certain direction on (001) plane was measured to be as high as a 2

Several donor-p-donor (D-p-D), acceptor-p-acceptor (A-p-A), and donor-p-acceptor (D-p-A) types of organic compounds with fluorene as p bridge and dimesitylboryl group as electron acceptor, which show strong two-photon excited blue fluorescence, have been synthesized and structurally investigated. The symmetric A-p-A type of compound exhibits the shortest wavelength of twophoton excited fluorescence (TPEF) at λem=405 nm under the excitation of λex=730nm; the unsymmetric D-p-A type of compound with diphenylamino as donor exhibits the most intense TPEF at blue region (λem=484 nm) with a two-photon absorption cross-section of 425GM under λex=800nm.

three-branched octupolar compound, 2,4,6-tris[2-(4-N,N-diethylamino)phenylethenyl]-1,3,5-s-triazine (compound III), as well as its one-and two-branched analogues (compounds I and II respectively) have been synthesized. The structures of I and II have been determined by X-ray diffraction. The linear and nonlinear spectra of these compounds regularly vary: (1) the spectral positions (lmax values) of the linear absorption, the single-photon excited fluorescence (SPEF) and the two-photon excited fluorescence (TPEF) show regular redshifts when the branch number increases from 1 to 3; (2) the spectral intensities, including the linear absorbance emax and the two-photon absorption cross-section s, the SPEF and the TPEF intensities are all increased significantly when going from I to III. The values of emax/MW and s/MW (of compounds I, II and III) vary with the ratios of 1.0: 1.3: 1.7 and 1.0: 1.4: 1.3, respectively. All the photophysical data indicate that by incorporating more branches into the triazine ring, the linear and nonlinear optical responses have been significantly enhanced, and that the spectral behaviour of II is closer to that of III, while more different from that of I. The single-branched compound I crystallizes in the noncentrosymmetric polar space group Cc. Its crystalline powder sample shows remarkable macro second-order nonlinear response with a SHG intensity of 46.8 times that of urea under a fundamental picosecond Nd: YAG laser beam (1064 nm). An important factor of such a large SHG intensity is that all the molecular dipoles take the same-oriented packing style that makes the crystal maximally polarized, fulfilling the optimization in the sense of crystal engineering.

We have synthesized two new organic salts, trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-Nmethylpyridinium toluene-p-sulfonate (abbreviated as HMASPS) and trans-4-[p-(N-hydroxyethyl-Nethylamino) styryl]-N-methylpyridinium toluene-p-sulfonate (abbreviated as HEASPS). X-Ray iffraction analyses reveal that HMASPS crystal belongs to the P21/n space group, with water olecules co-crystallized in the crystal and forming the monohydrate with the formula of C17H21N2Oz?C7H7O3S2?H2O, while HEASPS belongs to the P1