Chiung-Cheng Huang

Synthesis and photophysical properties of multinuclear zinc-salophen complexes: enhancement of fluorescence by fluorene termini.

Incorporation of fluorene groups into the salicylidene moiety significantly enhances the luminescence of a number of multinuclear alkynylated Zn(II)-salophen complexes. Preparation of these complexes was achieved by a synthetic strategy with facile handling of the reactants, simple purification of the products, and one-pot reaction process. Two synthetic methods are used for the preparation of different types of multinuclear salophen complexes. The introduction of a bis- or a tris-salicylaldehyde as a bridging unit in the presence of various alkynyl substituted monoimines in the reaction mixture containing zinc acetate resulted in the preparation of di- and tri-nuclear Zn(II)-salophen complexes of type 1, respectively. For a different type, treatment of tetraminobenzene with various arylethynyl-substituted salicylaldehyde afforded dinuclear Zn(II) alkynylated salophen complexes of type 2 with a different structure. The photophysical behaviors of these multinuclear metal salophen complexes were investigated. Particularly, the dinuclear complex 9b of type 1 having ethynylfluorene groups in salophen moieties and dialkoxyl groups in the bridging moiety exhibits higher quantum efficiency than that of other complexes in this report. In addition, the bis-Zn(II) alkynylated salophen complex 11e bearing nitrogen donor groups displays more red-shifted pattern than those with other functional substituents both in absorption and emission spectra.

Synthesis of photo-luminescent Zn(II) Schiff base complexes and its derivative containing Pd(II) moiety

An efficient method was developed for the preparation of a series of zinc Schiff base complexes. Introduction of a pyridyl group as a bridging unit as well as incorporation of ethynyl and electron-donating groups into the salicylidene moiety of these complexes moderately enhances the photoluminescence intensity and quantum yield. Electron-rich palladium groups possibly influence the photophysical character through the bridging C[triple bond]C bond. The crystal structure of the pyridine adduct of a salen Zn complex is determined by X-ray diffraction analysis.

Antiferroelectric liquid crystals based on the salicylaldimine in connection with linear alkynyl chain

A novel homologous series of chiral salicylaldimine-based liquid crystals in connection with linear alkynyl chain, C m YCBOC8* ( m = 6–10), have been synthesised and their mesomorphic phases have been studied. All of the materials possessed antiferroelectric smectic C (SmCA*) phase, which was confirmed by the observations of microscopic texture, switching current behaviour and dielectric permittivity.

Methyl 1-benzyl-1H-1,2,3-triazole-4-carboxyl­ate

In the title compound, C11H11N3O2, prepared by the [3+2] cycloaddition reaction of benzyl azide with methyl propiolate, the dihedral angle between the ring planes is 67.87 (11)°.

Wide blue phase range observed in simple binary mixture systems containing rodlike racemic biphenyl mesogens with 2-octyloxy tails

Four series of simple and rodlike racemic biphenyl mesogens possessing a 2-octyloxy tail and different substituents at the inner-core position of the phenyl ring were easily prepared. The mesophases of these racemic biphenyl mesogens were confirmed by variable-temperature XRD and the characteristic texture of POM. In general, cubic BPs can be induced by adding an appropriate ratio of chiral additive S811 or ISO(6OBA)2 into these racemic biphenyl mesogens during the heating and cooling processes. Interestingly, BPIII (5–6 K) easily dominates in highly chiral conditions for the blended mixture composed of mono-substituted biphenyl mesogens and chiral dopant S811. In addition, the formation temperature of BPIII is near room temperature (36 °C) when compound C6OBiPhI-OH is blended with 35 wt% S811 during the cooling process. Stable BPs with more than 20 K present in the blended mixture system were composed of chiral dopant ISO(6OBA)2 and no substituted biphenyl mesogens CnOBiPhI-H or difluoro substituted CnOBiPhI-FF. Notably, the widest temperature range of BP (∼34 K) can be induced by adding only 10 wt% chiral dopant ISO(6OBA)2 with high HTP into the biphenyl compound C6OBiPhI-H. The properties of the BPs were characterized by POM, DSC and reflection spectra. On the basis of our experimental results and molecular modeling, we demonstrated that the appearance and temperature range of BPs in this simple type of biphenyl mesogen with 2-octyloxy tail are affected by the molecular dipole moment and biaxiality.

Azido­(benzonitrile-κN)[hydrido­tris(pyrazol-1-yl-κN2)borato](triphenyl­phosphine-κP)ruthenium(II)

Facile ligand substitution is observed when the ruthenium–azide complex, [RuN3(Tp)(PPh3)2] [Tp,HB(pz)3, pz = pyrazolyl, PPh3 = triphenylphosphine] is treated with benzonitrile, yielding the title compound, [Ru(C9H10BN6)(N3)(C7H5N)(C18H15P)]. The asymmetric unit contains two crystallographically independent molecules. In each one, the RuII atom is six-coordinated in a distorted octahedral geometry by five N atoms from an htpb ligand, an azide ligand and a benzonitrile ligand and one P atom from a triphenylphosphine (tpp) ligand. The azide group is almost linear and is coordinated to Ru with an average Ru—N—N angle of 124.9 (3)°.

Chlorido[hydridotris(pyrazol-1-yl-κN2)borato](1H-pyrazole-κN2)(triphenyl­phosphine-κP)ruthenium(II)

In the title compound, [Ru(C9H10BN6)Cl(C3H4N2)(C18H15P)], the RuII atom is coordinated by an N,N′,N′′-tridentate hydridotrispyrazolylborate (Tp) ligand, a pyrazole (HPz) molecule, a chloride ion and a triphenylphosphine ligand, resulting in a distorted RuClPN4 octahedral coordination for the metal ion: the tridentate N atoms occupy one octahedral face and the Cl and P atoms are cis. One of the phenyl rings is disordered over two orientations in a 0.547 (10):0.453 (10) ratio, and a weak intramolecular N—H⋯Cl hydrogen bond generates an S(5) ring.