A gold(I) complex that exhibited aggregation-induced emission in acetonitrile-water mixtures was designed. It showed high selectivity and sensitivity for Hg²⁺ in acetonitrile-H₂O (1:1, V:V) solution. Dynamic light scattering measurements were conducted to verify that the addition of Hg²⁺ changed the particle size and induced fluorescence quenching.

Both planar and nonplanar polycyclic aromatic hydrocarbons (PAHs) have attracted attention owing to their potential applications in optoelectronic materials. Four twist benzopicenediimides with good optoelectronic properties have been reported previously. Following on from this work, four functionalized dibenzocarbazoles have been synthesized and reported herein. The fluorescence quantum yields of these compounds were high in dichloromethane and moderate in the solid state. They have interesting self-assembling behavior and tunable packing motifs in single crystals obtained by introducing different functional groups. Their good optoelectronic properties make them potential candidates for organic devices, bioimaging, and biolabeling.

A series of dinuclear ruthenium alkynyl and vinyl complexes bridged by carbazole, dibenzofuran, dibenzothiophene, and fluorenone have been prepared, and some representative molecular structures have been determined. The electrochemical and spectroscopic properties of the compounds were explored by cyclic voltammetry (CV), square-wave voltammetry (SWV), and in situ infrared and UV/Vis/near-IR spectroelectrochemical methods. The electrochemical results indicate that the greater the electron density on the ligand, the more stable the bridge-based oxidation product and the larger the electrochemical splitting. The UV/Vis/near-IR spectroelectrochemical studies revealed that the bridged ligands strongly contribute to or even dominate the oxidation processes. In addition, IR spectroelectrochemistry strengthens the theory of redox noninnocence in the bridging ligands, which was further confirmed by DFT calculations.

Four dithia[3.3]metaparacyclophane-bridged dimetallic ruthenium acetylide complexes (1–4), in which the cyclophane units exhibit characteristic edge-to-face interactions between the top and bottom aromatic decks, have been designed, synthesized, and structurally characterized. X-ray diffraction analysis of 1–3 revealed that effective edge-to-face interactions exist in the solid state. IR spectroelectrochemical results suggest that the dithia[3.3]metaparacyclophane bridging ligands are redox-noninnocent. The UV/Vis/NIR spectra of 1⁺, 2⁺, 3⁺, and 4⁺ display characteristic band envelopes, and the deconvoluted multiple transitions have been assigned with the aid of DFT calculations to combinations of metal-to-ligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT) with appreciable contributions from transannular π–π transitions, especially for 3⁺ and 4⁺.

The electronic properties of four divinylanthracene-bridged diruthenium carbonyl complexes [{RuCl(CO)(PMe₃)₃}₂(μCHCHArCHCH)] (Ar=9,10-anthracene (1), 1,5-anthracene (2), 2,6-anthracene (3), 1,8-anthracene (4)) obtained by molecular spectroscopic methods (IR, UV/Vis/near-IR, and EPR spectroscopy) and DFT calculations are reported. IR spectroelectrochemical studies have revealed that these complexes are first oxidized at the noninnocent bridging ligand, which is in line with the very small ν(CO) wavenumber shift that accompanies this process and also supported by DFT calculations. Because of poor conjugation in complex 1, except oxidized 1⁺, the electronic absorption spectra of complexes 2⁺, 3⁺, and 4⁺ all display the characteristic near-IR band envelopes that have been deconvoluted into three Gaussian sub-bands. Two of the sub-bands belong mainly to metal-to-ligand charge-transfer (MLCT) transitions according to results from time-dependent DFT calculations. EPR spectroscopy of chemically generated 1⁺–4⁺ proves largely ligand-centered spin density, again in accordance with IR spectra and DFT calculations results.

A series of binuclear ruthenium–alkynyl complexes that are bridged by thiophene groups (thiophene, bithiophene, and terthiophene) have been synthesized. All of these complexes have been well-characterized by NMR spectroscopy, X-ray diffraction, and elemental analysis. The electronic properties of these complexes have been examined by using cyclic voltammetry, UV/Vis/NIR and IR spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and density functional theory (DFT) calculations. Electrochemical results showed that the potential difference (ΔE) and comproportionation constant (K_c) decreased with increasing size of the thiophene bridging unit. The UV/Vis/NIR spectra and TDDFT calculations of the monocations indicated that the NIR transitions displayed aromatic bridging character. EPR studies of the mono-oxidized radical species further demonstrated that the unpaired electron/hole was delocalized over both metals and the bridging ligand and established significant participation in the ligand oxidation.

Simple model systems based on the 2,11-dithia[3,3]-metaparacyclophane skeleton were synthesized to study the effects of substituents on the intramolecular aromatic–aromatic interactions between benzene rings. X-ray crystallography established that, in their more stable conformations, these metaparacyclophanes featured partially overlapping aromatic rings (interplanar distances of about 3.5 Å), with the planes of the aromatic systems arranged in a slightly tilted disposition (interplanar angles in the range 5–19°). Calculations showed that these derivatives underwent topomerization by flipping of the meta-substituted ring over the para-substituted one, a process in which the two rings adopted a continuum of edge-to-face dispositions, including an orthogonal one, which were less stable than the starting face-to-face arrangement. The energy barriers to the isomerization process were experimentally determined by variable-temperature NMR spectroscopy, by using an internal temperature standard to assess even minor differences in energy (relative experimental error: (±0.1 kJ mol⁻¹). The variation in the barriers as a function of the different substituents on the interacting ring was small and apparently unrelated to the effect of the substituents on the polarity of the π-systems. An explanation based on the charge-penetration effect seemed more-suitable to rationalize the observed trends in the barriers.

A series of chiral 1-(β-arylalkyl)-1H-1,2,4-triazole derivatives has been designed as potential antifungal agents. The target triazoles have been synthesized by using a chiral auxiliary as a controlling reagent. All of the compounds were obtained with high ee values, reaching up to 99%. Preliminary bioassay results have revealed that most of the synthesized compounds display significantly higher fungicidal activities against the species Fusarium oxysporium, Rhizoctonia solani, Botrytis cinereapers, Gibberella zeae, Dothiorella gregaria, and Colletotrichum gossypii than the commercial agent triadimefon. Moreover, some of the enantiomers have been found to display significant differences in activity.

The Sonogashira cross-coupling of aryl iodides with terminal alkynes catalyzed by a simple and inexpensive catalyst system of CuI/PPh₃ in water as the sole solvent has been reported. In the presence of CuI/PPh₃, with KOH used as a base, a number of aryl iodides were treated with alkynes to afford the corresponding products in moderate to excellent yields. Copyright © 2008 John Wiley & Sons, Ltd.