The synthesis, structure, and fluorescence properties of a series of new donor -π- acceptor (D-π-A) type compounds, with a trivalent boron, protected by two mesityl groups, as acceptor, and with various typical donors and different-conjugated bridges, are reported. All these stable organoboron compounds show intense singlephoton excited fluorescence (SPEF) and two-photon excited fluorescence (TPEF) in a wide spectral range from blue to green, with the spectral peak position of the SPEF being basically the same as that of the TPEF. The remarkably strong C B(mesityl)2 bonding, and the well-conjugated -system, shown in X-ray crystal structures of two compounds, indicate some charge transfer features of the ground state. Meanwhile, spectral data indicate that the charge transfer from donor to acceptor is greatly enhanced in the excited states. Based on typical structural data and comprehensive spectral data, the following structure-property relationships can be drawn: 1) the moderate arylamino donor can more effectively enhance the SPEF and TPEF intensities than can the strong alkylamino donor; 2) stilbene is a better-bridge than styrylthiophene for its capability of enhancing and blueshifting the SPEF and TPEF of the corresponding D-π-A compounds; and 3) when compared to its boron-free precursors and other analogues, -B(mesityl) 2 invariably and consistently acts as an effective SPEF and TPEF fluorophore in all this series of organoboron compounds, which may result from its strong-electron-withdrawing and charge transfer-inducing nature in the ground-state and, more dominantly, in the excited-state. Combining all the above positive structure factors, trans-4-N,N-diphenylamino-4-dimesitylborylstilbene (compound 3) stands out as the optimized green SPEF and TPEF emitter. This compound exhibits an SPEF quantum yield of 0.91 at 522 nm in THF, a TPEF cross-section that is an order of magnitude larger than that of its boron-free precursor upon excitation by 800nm femto-second laser pulses, and a two-photon absorption section of 3.0 10 48 cm4 s. In the blue light region, trans-4 -N-carbazolyl-4-dimesitylborylstilbene (compound 4) shows significant SPEF and TPEF properties, with 0.79 at 464 nm in THF and a large value, which is five times that of fluorescein upon excitation by 740 nm femto-second laser pulses.

A series of new donor–p-acceptor type compounds with trivalent boron as acceptor which show strong two-photon excited up-conversion fluorescence have been synthesized and one crystal structure described.

Three new A-π-A-type compounds with trivalent boron, protected by two mesityl groups, as electron acceptor have been synthesized and investigated together with their two diphenylamino-ended D-ð-D analogues. These boranes exhibit large two-photon absorption cross sections and high fluorescence quantum yields.

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

A new electrical conductive crystal PyEt[Ni(dmit)2]2 (dmit=4,5-dimercapto-1,3-dithiole-2-thione) has been synthesized and its X-ray structure has been determined to be in monoclinic system, C2/c space group. In PyEt[Ni(dmit)2]2 crystal, the conducting component [Ni(dmit)2]0.5− is face-to-face packed forming molecular column along the c-direction, and these molecular columns are then side-by-side extended along the a-direction forming a kind of two-dimensional conducting sheet on (010). The measured conductivity at room temperature along a certain direction on (010) plane is 10 S cm−1. From 282 to 269 K, the crystal shows metallic behavior but changes to semiconductor below 269 K. Based on the measured crystal structure and calculated band structure, this conductor-semiconductor phase transformation can be primarily interpreted: The metallic conductivity is corresponding to the uniform molecular column and the atomic-lattice-chain structure of Ni chain, while the semi-conductive behavior to staggered molecular column and the atomic-zigzag-chain structure of Ni chain.