Combined Effects of Temperature and the Microcystin MC-LR on the Feeding Behavior of the Rotifer Brachionus calyciflorus.

The aim of this study was to investigate the responses in filtration and grazing rates of five rotifer strains of the species Brachionus calyciflorus under different temperatures and MC-LR concentrations. The results showed that strain identity, MC-LR concentration, temperature, and the interactions of these factors significantly affected both response variables, with the exception of the interaction of strain and MC-LR on the grazing rates. At low MC-LR concentrations and for the control group, the filtration and grazing rates increased with increasing temperature. The filtering and grazing rates of B. calyciflorus exposed to higher MC-LR concentrations, however, showed no evident enhancement with increasing of temperature. At high temperatures, the filtration and grazing rates of all rotifer strains decreased significantly with increasing concentration of MC-LR, however B. calyciflorus exhibited a refractory stability in the presence of increased MC-LR levels at lower temperatures.

Crystal structure, photoluminescence and electroluminescence of three bluish green light-emitting iridium complexes.

Three bis-cyclometalated iridium complexes ((TPP)2Ir(acac), (TPP)2Ir(tpip) and (TPP)2Ir(pic)) with 2-(2-trifluoromethyl)pyrimidine-pyridine (TPP) as the main ligand, 2,4-pentanedionate (acac), tetraphenylimidodiphosphinate (tpip) and picolinate (pic) as the ancillary ligands, respectively, were prepared. Their photoluminescence and electrochemistry properties were investigated in detail, and (TPP)2Ir(tpip) was also examined by X-ray crystallography. These complexes show bluish green emission with a quantum efficiency of 11-14%. The organic light emitting diodes (OLEDs) with the structure of ITO/TAPC (1,1-bis[4-(di-p-tolylamino)phenyl]cyclohexane, 40 nm)/mCP (1,3-bis(9H-carbazol-9-yl)benzene, 10 nm)/Ir complex (8 wt%):PPO21 (3-(diphenylphosphoryl)-9-(4-(diphenylphosphoryl)phenyl)-9H-carbazole, 25 nm)/TmPyPB (1,3,5-tri(m-pyrid-3-yl-phenyl)benzene, 50 nm)/LiF (1 nm)/Al (100 nm) were fabricated to evaluate the potential application of these complexes. A (TPP)2Ir(tpip) emitter based device showed the best performance of a maximum current efficiency (ηc) value of 37.61 cd A(-1) and a maximum external quantum efficiency (EQE) of 13.7% with low efficiency roll-off.

Syntheses, photoluminescence, and electroluminescence of a series of iridium complexes with trifluoromethyl-substituted 2-phenylpyridine as the main ligands and tetraphenylimidodiphosphinate as the ancillary ligand.

Five bis-cyclometalated iridium complexes with tifluoromethyl-substituted 2-phenylpyridine (ppy) at different positions of its phenyl group as the main ligands and tetraphenylimidodiphosphinate (tpip) as the ancillary ligand, 2-6 (1 is a trifluoromethyl-free complex), were prepared, and their X-ray crystallography, photoluminescence, and electrochemistry were investigated. The number and positions of trifluoromethyl groups at the phenyl ring of ppy greatly affected the emission spectra of Ir(3+) complexes, and their corresponding emission peaks at 533, 502, 524, 480, and 542 nm were observed at room temperature, respectively. Constructed with complexes 2-6 as the emitters, respectively, the organic light-emitting diodes (OLEDs) with the structure of indium-tin oxide/1,1-bis[4-(di-p-tolylamino)phenyl]cyclohexane (30 nm)/Ir (x wt %):bis[3,5-bis(9H-carbazol-9-yl)phenyl]diphenylsilane (15 nm)/1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (45 nm)/LiF (1 nm)/Al (100 nm) showed good performances. Particularly, device G4 based on 4-trifluoromethyl-substituted complex 4 with x = 8 wt % obtained a maximum luminance of over 39000 cd m(-2) and maximum luminance efficiency (η(L)) and power efficiency (η(p)) of 50.8 cd A(-1) and 29.0 lm W(-1), respectively. The results suggested that all of the complexes 2-6 would have potential applications in OLEDs.

Synthesis and photoluminescence properties of rhenium(I) complexes based on 2,2':6',2''-terpyridine derivatives with hole-transporting units.

Based on 2,2':6',2''-terpyridine ligands (L1), five terpyridine derivatives, namely 4'-carbazol-9-yl-2,2':6',2''-terpyridine (L2), 4'-diphenylamino-2,2':6',2''-terpyridine (L3), 4'-bis(4-tert-butylphenyl)amino-2,2':6',2''-terpyridine (L4), 4'-[naphthalen-1-yl-(phenyl)amino]-2,2':6',2''-terpyridine (L5), 4'-[naphthalen-2-yl(phenyl)amino]-2,2':6',2''-terpyridine (L6) and their corresponding Re(I) complexes ReL(n)(CO)3Cl (n = 1­6) have been synthesized and characterized by elemental analysis and 1H NMR spectroscopy. The X-ray crystal structure of ReL3(CO)3Cl has also been obtained. The luminescence spectra of ReL2(CO)3Cl­ReL5(CO)3Cl, obtained in CH2Cl2 solution at room temperature, show strong dπ (Re) → π* (diimine) MLCT character (λ(max) 600 nm) and a small red shift relative to ReL1(CO)3Cl. This, confirmed by the study of the triplet energy levels of the L1­L6 ligands at low temperature (77 K rigid matrix), indicates that the introduction of electron-donating moieties on the terpyridine unit decreases the triplet levels of the ligands, leading to a reduction of the energy gap between d and π* orbitals. In the solid state, upon MLCT excitation, all the complexes show an even stronger emission and a blue spectral shift (λ(max) ∼ 550 nm) compared to those obtained in solution.