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Eucalyptus urophylla was treated with melamine-urea-formaldehyde resin (MUF) after pretreatment with urea solution. The properties of the wood were then determined.The weight percent gain (WPG) and, antiswelling efficiencies (ASE) of the wood treated with urea+MUF were 14% and, 45% higher than those of untreated wood, respectively. The water absorption (WA) of the wood treated with urea+MUF was decreased approximately 50% lower than that of the untreated wood. However, the mechanical properties of the wood treated with urea+MUF were weakened due to the destruction of the structure of wood. An X-ray photoelectron spectroscopy (XPS) analysis revealed that the atomic concentration ratio of O/C was increased. The ratio of C1 was decreased as the lignin and extractives contents were decreased, while theratios of C2 and C3 were increased. The urea solution pretreatment was conducive to theimpregnation of wood functional modifiers.

The subcellular localization of proteins is a fundamental aspect of protein functions. Determining the subcellular localization is important for understanding the biological functions of proteins. Here, we developed a set of rice organelle marker lines, in which the expressing fluorescent organelle markers could be used as comparative standards in determining the subcellular localization of the protein of interest. We constructed green fluorescent protein (GFP)- and/or Discosoma sp. red fluorescent protein (DsRed)-tagged organelle markers targeted to the endoplasmic reticulum (ER), mitochondria, Golgi apparatus, peroxisome, actin cytoskeleton, plastid, tonoplast, plasma membrane, and nucleus, respectively. The utility of the rice marker lines for protein subcellular localization studies was demonstrated by detecting a nucleus-localized OsWRKY45 and a mitochondria-associated NbHxk1 in protoplasts of the GFP-OsH2B and the ScCOX4-DsRed lines, respectively. Using a sheath-inoculation method, followed by a live-cell imaging, we detected co-localization of a Magnaporthe oryzae PWL2:mCherry : NLS fusion with the nucleus marker in the GFP-OsH2B rice epidermal cells, confirming the translocation of the M. oryzae effector PWL2 into host cells, and further demonstrating the feasibility of using the organelle marker lines for studying dynamics of proteins in rice cells in the interactions between rice and pathogens. The set of organelle marker lines developed in the present study, provides a valuable resource for protein subcellular localization studies in rice.

Hexapodal ligand H 6 L containing imidazole groups has been prepared by the reaction of 1,2,3,4,5,6-hexakis[(4-formylphenoxy)methyl]benzene with 1,10-phenanthroline-5,6-dione. Hexanuclear complex [RuH 6 L](PF 6 ) 12 has been obtained by the condensation of Ru(bpy) 2 Cl 2 ·2H 2 O and H 6 L, and isolated as PF 6 − salt. The deprotonated complex [RuL] 6+ was achieved by reaction of sodium methoxide with complex [RuH 6 L] 12+ in methanol. The pH effects on the UV–vis absorption and fluorescence spectra of complex [RuH 6 L](PF 6 ) 12 are studied, and ground and excited state ionization constants of the complex are derived. The absorption and fluorescence spectra of the complex are both strongly dependent on the solution pH. Complex [RuH 6 L](PF 6 ) 12 acts as “on–off” fluorescence pH sensor through protonation and deprotonation of imidazole groups with a maximum on–off ratio of 5 in buffer solution at room temperature.

Three novel chiral salen-like schiff base ligands and their Mn(III) complexes containing different amino acid unit have been synthesized and characterized. Asymmetric epoxidation reactions show these complexes are effective catalysts for the chromenes with buffer NaOCl as terminal oxidant and pyridine N-oxide as co-catalyst in the presence of ionic liquid. Good-to -excellent enantioselectivity and acceptable yields can be obtained under optimum reaction conditions. Catalyst 4c gives the highest ee (95%) for 6-chloro-2,2-dimethylchromene among these catalytic performances. Furthermore, compared the enantioselectivity of catalyst 4c with the other two catalysts 4a and 4b, the positive experimental results suggest that the steric effect of the ligands plays an important role in the asymmetric catalysis. Asymmetric epoxidation of chromenes with Mn (III) complex containing amino acid moiety

Several chiral unsymmetrical and C 2 -symmetric Mn(III)-BINOL-Salen complexes have been designed, synthesized and applied to the asymmetric epoxidation of non-functionalized alkenes. Experimental results show these complexes are effective in the catalytic asymmetric epoxidation of alkenes. The catalyst 4c exhibited better enantioselectivity and reactivity than the catalysts 4b and 4a due to the steric effect of the ligands. To understand the synergistic effect of the two different chiral centers in the catalyst, the catalyst 6a has been investigated. By comparison of the enantioselectivity obtained by using 4c and 6a , respectively, the positive experimental results have proved that the chiral stereogenic centers in the diaminocyclohexane-derived catalysts played an important role in the current enantioselective epoxidation. Besides, the comparison of enantioselectivity displayed by 4c and 7a further demonstrates the significant influence through the cooperation of steric factors and chiral centers in catalyst.

A series of four tripodal ligands L1–4 were prepared by the reaction of 9-(2-hydroxy)phenylimino-4,5-diazafluorene with 1,3,5-tris(bromomethyl)benzene, 1,3,5-tris(bromomethyl)-2,4,6-trimethylbenzene, tris(2-chloroethyl)amine hydrochloride, and pentaerythrityl tetratosylate, respectively, in DMF solution under nitrogen. For each ligand, Ru(II) complexes were prepared by refluxing Ru(bipy)2Cl2 · 2H2O and ligand in 2-methoxyethanol. Photophysical behaviors of these Ru(II) complexes have been investigated by UV-Vis absorption and luminescence spectrometry. They display metal-to-ligand charge transfer absorption at 442 nm in MeCN solution at room temperature and emission at 574 nm in EtOH–MeOH (4 : 1, v/v) glassy matrix at 77 K. Electrochemical studies of the Ru(II) complexes show one Ru(II)-centered oxidation at 1.33 V and three ligand-centered reductions.

Two polypyridyl ligands, 4`-(4,5-diazafluoren-9-ylimino)benzo-15-crown-5 (L1) and 4` -(4,5-diazafluoren- 9-ylimino)benzo-12-crown-4 (L2), and their Ru(II) complexes [(bpy)2RuL1](PF6)2 and [(bpy)2RuL2](PF6)2, respectively, have been synthesized and characterized. The two complexes display metal-to-ligand charge transfer absorptions at around 444 nm in CH3CN solution at r. t. and emission at around 573 nm in an EtOH-MeOH (4 : 1, v/v) glassy matrix at 77 K. Electrochemical studies of the complexes show one Ru(II)-centered oxidation at around 1.33 V and three ligandcentered reductions. The binding ability of the complexes with Na+ and Li+ has been investigated by UV/Vis absorption and emission spectroscopy and electrochemical titrations. Addition of Na+ and Li+ to solutions of the complexes results in a progressive quenching of the emission, a hyperchromic effect of the UV/Vis absorption, and a progressive cathodal shift of the Ru(II)-centered E1/2 potential. The stability constants for the stoichiometric 1 : 1 ratio of the complexes and the cations have been obtained by UV/Vis absorption titration.

Tetrapodal ligands tetrakis{4-((1,10-phenanthroline-[5,6-d]imidazol-2-yl)phenoxy)methyl}methane (L1), tetrakis{3-((1,10-phenanthroline-[5,6-d]imidazol-2-yl)phenoxy)methyl}methane (L2), and corresponding Ru(II) complexes [(bpy)8L1–2(RuII)4](PF6)8, shortly called Ru–L1–2, have been synthesized and characterized. The pH effects on UV–vis absorption and fluorescence spectra of the two complexes are studied, and ground- and excited-state ionization constants of the two complexes are derived. The two complexes act as pH-induced “off–on–off” fluorescence switches through protonation and deprotonation in buffer solution at room temperature.

Three tripodal ligands H3L1–3 containing imidazole rings were synthesized by the reaction of 1,10-phenanthroline-5,6-dione with 1,3,5-tris[(3-formylphenoxy)methyl]benzene, 1,3,5-tris[(3-formylphenoxy)methyl]-2,4,6-trimethylbenzene, and 2,2′,2"-tris[(3-formylphenoxy)ethyl]amine, respectively. Trinuclear RuII polypyridyl complexes [(bpy)6Ru3H3L1–3](PF6)6 were prepared by the condensation of Ru(bpy)2Cl2·2H2O with ligands H3L1–3. The pH effects on the UV/Vis absorption and fluorescence spectra of the three complexes were studied, and ground- and excited-state ionization constants of the three complexes were derived. The three complexes act as “off-on-off” fluorescence pH switch through protonation and deprotonation of imidazole ring with a maximum on-off ratio of 5 in buffer solution at room temperature.

A novel sterically bulky phenol (2,4-di-tert-butyl-6-(1-(3,5-di-tert-butyl-2-(2-(2-methoxyethoxy)ethoxy)phenyl)ethyl)phenol)(HL) and corresponding dimeric sodium and potassium complexes [ML]2 (1: M = Na, 2: M = K) have been prepared and structurally characterized. Experimental results showed that complexes 1 and 2 can efficiently initiate the ring-opening polymerization of lactide in a controlled fashion, yielding polymers with expected molecular weight and low polydispersity indexes.

Four tripodal ligands L1–4 derived from 4,5-diazafluoren-9-one were synthesized. L1–2 formed by the reaction of 4,5-diazafluoren-9-oxime with 1,3,5-tris(bromomethyl)benzene, and 1,1,1-tris(p-tosyloxymethyl)propane, respectively and L3–4 formed by the condensation of 9-(4-hydroxy)phenylimino-4,5-diazafluorene with 1,3,5-tris(bromomethyl)benzene, and 1,1,1-tris(p-tosyloxymethyl)propane, respectively. Four trinuclear complexes [(bpy)6Ru3L1–4](PF6)6 (Ru-L1–4) were obtained by reaction of Ru(bpy)2Cl2·2H2O with ligands L1–4. The photophysical behaviors of these complexes were investigated by UV/Vis absorption and emission spectrometry. The complexes display metal-to-ligand charge transfer absorptions at 441–445 nm and emissions at 571–578 nm. Cyclic voltammetry data of the complexes show one RuII-centered oxidation and three successive ligand-centered reductions.

Two symmetric tetrapodal ligands L1–2 and one asymmetric tetrapodal ligand L3 based on 4,5-diazafluoren have been synthesized and characterized. Ligands L1–2 formed by the condensation of pentaerythrityl tetratosylate with 4,5-diazafluoren-9-oxime and 9-(4-hydroxy)phenylimino-4,5-diazafluorene, respectively. L3 was prepared by two steps, 9-(4-hydroxy)phenylimino-4,5-diazafluorene reacted with pentaerythrityl tetratosylate affording 1,1′,1"-tris[(4,5-diazafluoren-9-ylimino)phenoxymethyl]-1"′-(p-tosyloxymethyl)-methane, which reacted with 4,5-diazafluoren-9-oxime affording the asymmetric ligand L3. Three tetranuclear RuII complexes [(bpy)8L1–3Ru4](PF6)8 (bpy = bipyridine) were obtained by the reaction of Ru(bpy)2Cl2·2H2O with ligands L1–3. Spectroscopic studies of these complexes exhibit metal-to-ligand charge transfer absorptions at 440–445 nm and emissions at 575–579 nm. The electrochemical behaviors of these complexes are consistent with one RuII-based oxidation couple and three ligand-centered reduction couples.

The reactions of 2,2′-ethylidene-bis(4,6-di-tert-butylphenol) (EDBPH2) with sodium/potassium and (nBu)2 Mg in tetrahydrofuran (THF), give [(EDBP)2 Mg][(Na)2(THF)5]·THF (1) and [(EDBP)2 Mg][(K)2(THF)5]·THF (2) in high yield. Experimental results show that sodium/potassium complexes 1 and 2 are efficient catalysts for the ring-opening polymerization of lactides. Furthermore, complexes 1 and 2 have slight isotactic selectivity for the ring-opening polymerization of rac-lactide.

Tripodal ligands 1,3,5-tris{4-((1,10-phenanthroline-[5,6-d]imidazol-2-yl)phenoxy)methyl}-2,4,6-trimethylbenzene (L 1 ), 1,1,1-tris{4-((1,10-phenanthroline-[5,6-d]imidazol-2-yl)phenoxy)methyl}propane (L 2 ), 2,2′,2′′-tris{4-((1,10-phenanthroline-[5,6-d]imidazol-2-yl)phenoxy)ethyl}amine (L 3 ), and corresponding Ru(II) complexes [(bpy) 6 L 1–3 (Ru II ) 3 ](PF 6 ) 6 , shortly called (Ru–L 1–3 ), have been synthesized. UV–vis absorption and fluorescence spectra of these complexes are both strongly dependent on the pH of the buffer solution. These complexes act as pH-induced off–on–off fluorescence switch through protonation and deprotonation of the imidazole-containing ligands.

Three novel ternary copper(II) complexes, [Cu 2 (phen) 2 ( l -PDIAla)(H 2 O) 2 ](ClO 4 ) 2 ·2.5H 2 O ( 1 ), [Cu 4 (phen) 6 ( d , l -PDIAla)(H 2 O) 2 ](ClO 4 ) 6 ·3H 2 O ( 2 ) and [Cu 2 (phen) 2 ( d , l -PDIAla)(H 2 O)](ClO 4 ) 2 ·0.5H 2 O ( 3 ) (phen = 1,10-phenanthroline, H 2 PDIAla = N , N’ -( p -xylylene)di-alanine acid) have been synthesized and structurally characterized by single-crystal X-ray crystallography and other structural analysis. Spectrometric titrations, ethidium bromide displacement experiments, CD (circular dichroism) spectral analysis and viscosity measurements indicate that the three compounds, especially the complex 3 , strongly bind to calf-thymus DNA (CT-DNA). The intrinsic binding constants of the ternary copper(II) complexes with CT-DNA are 0.89 × 10 5 , 1.14 × 10 5 and 1.72 × 10 5 M −1 , for 1 , 2 and 3 , respectively. Comparative cytotoxic activities of the copper(II) complexes are also determined by acid phosphatase assay. The results show that the ternary copper(II) complexes have significant cytotoxic activity against the HeLa (Cervical cancer), HepG2 (hepatocarcinoma), HL-60 cells (myeloid leukemia), A-549 cells (pulmonary carcinoma) and L02 (liver cells). Investigations of antioxidation properties show that all the copper(II) complexes have strong scavenging effects for hydroxyl radicals and superoxide radicals.

Four tripodal ligands 2,2′,2″-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxyethyl]amine (L1), 1,1,1-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]propane (L2), 1,3,5-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]-2,4,6-trimethylbenzene (L3), 1,3,5-tris[4-(4,5-diazafluoren-9-ylhydrazinyl)methylenephenoxymethyl]benzene (L4), and corresponding Ru(II) complexes [(bpy)6L1–4(RuII)3](PF6)6 (Ru-L1–4) have been synthesized. Cyclic voltammetry of these complexes comprise one Ru(II)-centered reversible oxidation and three ligand-centered reductions. Photophysical behaviors are investigated by UV–Vis absorption and luminescence spectrometry. These complexes display metal-to-ligand charge transfer absorption at around 410 nm and emission at around 582 nm.

One novel hexapodal ligand 1,2,3,4,5,6-hexakis[(4,5-diazafluoren-9-yliminoxy)methyl]benzene (L) and corresponding Ru(II) polypyridyl complex [(bpy) 12 (Ru II ) 6 L](PF 6 ) 12 have been synthesized. Spectroscopic properties of the complex are investigated by UV–Vis absorption and fluorescence spectrometry. The complex shows metal-to-ligand charge transfer absorption at 438 nm and emission at 579 nm. Cyclic voltammetry of the complex comprises one Ru(II)-centered quasi-reversible oxidation at 1.31 V and three ligand-centered reductions.

Two new chiral dinuclear Mn(III)-Salen complexes with inherent phase-transfer capability have been synthesized, which serve as catalysts in the asymmetric epoxidation of nonfunctionalized alkenes. Experimental results show these complexes are effective catalysts for the asymmetric epoxidation of some cyclic alkenes and the catalysts have certain inherent phase-transfer capability during the epoxidation because of their weak water solubility. In general, good enantioselectivity and acceptable yields were achieved when NaClO was used as oxidant under three different reaction systems. Among these alkenes, the catalyst 6a gave the highest ee (94%) for 6-chloro-2,2-dimethylchromene in the presence of ionic liquid 2. Additionally, the recovery and recycling of one dimeric Mn(III)-Salen complex were tested to investigate atom efficiency of the catalyst in different reaction systems on the alkenes epoxidations. The catalyst 6a could be recovered and recycled for six times without losing activity and selectivity. Chirality, 2011. © 2010 Wiley-Liss, Inc.

With a bistridentate Schiff-base ligand, N',N'(3)-bis[(1E)-1-(2-pyridinyl)ethylidene)] isophthalohydrazide (H(2)L), a [2x2]G grid complex, [Ni(4)(HL)(4)](ClO(4))(4).4H(2)O.0.5 CH(3)OH (1) has been synthesized and characterized spectroscopically and crystallographically. Spectrometric titrations, ethidium bromide displacement experiments, circular dichroism spectral analysis and viscosity measurements indicate that the compound 1 strongly binds with calf-thymus DNA, presumably via intercalation mechanism. Furthermore, the antioxidant activity (superoxide and hydroxyl radical) of the ligand and its nickel(II) complex is determined by using spectrophotometer methods in vitro. Complex 1 is found to possess potent antioxidant activity and be better than standard antioxidants like mannitol.

In this study, two novel complexes [Cu(MCVH)phen(H(2)O)].ClO(4) (1) and [Cu(MCLH)phen(H(2)O)].ClO(4) (2) (here, MCVH(2)=(7-hydroxy-4-methyl-8-coumarinyl) valine, MCLH(2)=(7-hydroxy-4-methyl-8-coumarinyl) leucine) have been synthesized and characterized by elemental analyses, molar conductance, infrared spectra (IR), (1)H-NMR and UV-Vis measurements. The interactions of them with calf thymus DNA (ct DNA) have been investigated by absorption spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and viscosity measurements. Experimental results reveal an intercalative interaction with DNA for the complexes, furthermore the binding affinity of 2 is higher than that of 1 according to the calculated binding constant values. In addition, they were evaluated for their cytotoxic activities toward human prostate cancer cell (PC3), human liver cell (L02) and human myeloid leukemia cancer cell (HL-60) by acid phosphoatase assay. Both of them showed significant cytotoxic potency.