Search

A novel erbium material with a fascinated mercury bromide cluster (Hg11Br34)12– anion, i.e., {[Er2(H2O)4(HIA)6]2n}(nHg11Br34)(nHgBr2)·4nH2O (denoted as 1 and HIA indicates the isonicotinic acid molecule), was successfully synthesized from a solvothermal reactor. Its single crystal structure was determined by single-crystal and powder X-ray diffractions. The Er3+ ions have a distorted square antiprism motif, and they are connected by isonicotinic acid molecules to yield a one-dimensional (1-D) chain. The Hg2+ ions show two or four coordination motifs. This compound contains an unprecedented mercury bromide cluster (Hg11Br34)12– anion. This compound shows upconversion green photoluminescence emission with a CIE (Commission Internationale de I'Eclairage) chromaticity coordinates at (0.1749, 0.4351). It has a wide band gap of 3.24 eV. A novel erbium material with a fascinated mercury bromide cluster (Hg11Br34)12– anion was reported. The Er3+ ions have a distorted square antiprism motif and the compound features a 1-D chain-like structure. The Hg2+ ions show two or four coordination motifs. It features upconversion green emission with CIE coordinates 0.1749 and 0.4351. It has a wide band gap of 3.24 eV.

Under hydrothermal conditions, a novel bimetallic thulium–mercury compound {[Tm(H2O)2(IA)3]2n[(Hg6Br13)n]}(nHgBr2)·4nH2O·nH3O (1) (IA = isonicotinato anion) was prepared and the crystal structure was characterized by single-crystal and powder X-ray diffraction. It is characterized by a three-dimensional (3D) framework with a novel two-dimensional (2D) inorganic [(Hg6Br13)n] layer. Solid-state photoluminescence measurements revealed that compound 1 emits upconversion mazarine emission bands, which are originated from the 1G4 → 3H6 and 1D2 → 3H4 characteristic emissions of the 4f electron intrashell transitions of Tm(III) ions. An energy transfer mechanism is reported. Compound 1 displays CIE chromaticity coordinates of 0.1288 and 0.0635 in the mazarine region. A solid-state UV–Vis–NIR diffuse reflectance spectrum unveiled that compound 1 has a wide optical band gap of 2.69 eV. A thermogravimetry analysis measurement is also reported. A novel bimetallic thulium–mercury compound was prepared and characterized. It features a 3D framework with a novel 2D inorganic [(Hg6Br13)n] layer. It contains many mercury(II) ions with four different coordination environments. It emits upconversion mazarine photoluminescence emission peaks, which could be attributed to the 1G4 → 3H6 and 1D2 → 3H4 characteristic emissions of the 4f electron intrashell transitions of the Tm(III) ions. An energy level diagram was used to explain the energy transfer mechanism. It has CIE chromaticity coordinates of 0.1288 and 0.0635 in the mazarine region, and it possesses a wide optical band gap of 2.69 eV.

A novel 4f-5d compound [Tb(HIA)2(IA)(H2O)2(HgCl2)]n(nHgCl4)·3nH2O (1, IA = isonicotinate anion) has been prepared and structurally determined by X-ray diffraction. Complex 1 crystallizes in the P21/c space group of the monoclinic system with a = 9.6875(3), b = 19.8318(7), c = 17.0899(5) A, β = 101.609(3)o, V = 3216.16(18) A3, C18H24Cl6Hg2N3O11Tb, Mr = 1231.20, Z = 4, Dc = 2.543 g/cm3, μ(MoKα) = 12.251 mm–1 and F(000) = 2272. The crystal structure of complex 1 is characterized by a two-dimensional (2-D) layer-like structure. The photoluminescence measurements with solid-state samples reveal that it exhibits a yellowish green emission with the emission bands locating at 490, 546, 586 and 620 nm, respectively. The photoluminescence emission bands are resulted from the characteristic emission of the 4f electrons intrashell transition of the 5D4 → 7FJ (J = 6, 5, 4, 3) of the Tb3+ ion. The energy transfer mechanism is explained by using the energy level diagram of the Tb3+ ion and isonicotinic acid ligand. Complex 1 exhibits CIE chromaticity coordinates being of 0.3823 and 0.5141. A solid-state diffuse reflectance measurement shows that the complex possesses a wide optical band gap of 2.67 eV. A novel 4f-5d compound featuring a 2-D layer-like structure has been reported for the crystal structure and properties.

A novel 4f–5d compound [Ho(H2O)2(μ-IA)3Hg3Br6]n (1, HIA = isonicotinic acid) was prepared. It is characterized by single-crystal X-ray diffraction. The title compound crystallizes in the space group P21/n of the monoclinic system. The holmium ion is coordinated by six oxygen atoms to yield a slightly distorted tetragonal antiprism configuration. Three crystallographically independent mercury ions exhibit two different coordination environments, i.e., tetrahedron geometry and square pyramidal configuration. In the title compound, there are two types of one-dimensional (1D) chains, namely Hg–Br chains and Ho–IA chains. Both chains are interconnected by the μ3-bridging isonicotinic acid ligands to form a three-dimensional (3D) frame structure. Photoluminescence from solid samples showed that the title compound could emit up-conversion red fluorescence, and its half-peak width was about 14 nm. The emission peak comes from its characteristic emission of 5F5 → 5I8 of Ho3+. The CIE color coordinates of the title compound are (0.693, 0.307). The title compound displays a broad semiconductor gap being of 2.47 eV, as discovered by the solid-state diffuse reflection. A novel 4f–5d compound has been prepared. It features a 3D framework structure. It displays a red up-conversion photoluminescence emission band. Diffuse reflection spectrum with solid-state sample shows that it possesses a wide optical band gap of 2.47 eV.

A terbium material is prepared under hydrothermal conditions and structurally characterized by X-ray diffraction technique. This compound is characterized by an isolated structure. Solid-state photoluminescence measurement discovers that it shows a strong emission in the green region. The sharp bands at 490, 544, 585, and 620 nm correspond to the characteristic emission 5D4–7FJ transitions (J = 6, 5, 4, and 3, respectively) of the Tb3+ ions. Solid-state diffuse reflectance spectrum reveals that the existence of a wide optical bandgap of 4.83 eV, indicating that it is potentially a wide band-gap semiconductor. Magnetic properties of the compound are investigated. The magnetic susceptibility obeys the Curie–Weiss law (χm = c/( T− θ)) with c = 10.55(8) K and a negative Weiss constant θ = − 1.11(7) K; this suggests the presence of an antiferromagnetic interaction in this compound. A terbium compound has been prepared and it features an isolated structure. Solid-state photoluminescence measurement reveals that it shows a strong emission in the green region. Solid-state diffuse reflectance spectrum reveals an optical bandgap of 4.83 eV. Magnetic properties discover that it features antiferromagnetic interaction.

Wheat kernel morphology is a very important trait for wheat yield improvement. This is the first report of association analysis of kernel morphology traits in wheat breeding lines. In Qinghai, China, the research described here involved genome-wide association analysis in breeding lines derived from synthetic hexaploid wheat with a mixed linear model to identify the quantitative trait loci (QTLs) related to kernel morphology. The 8033 effective Diversity Array Technology (DArT) markers produced a genetic map of 5901.84 cM with an average density of 1.36 markers/cM. Population structure analysis classified 507 breeding lines into three groups by Bayesian structure analysis using unlinked markers. Linkage disequilibrium decay was observed with a map coverage of 2.78 cM. Marker-trait association analysis showed that 15 DArT markers for kernel morphology were detected, located on nine chromosomes, and explained 2.6%–4.0% of the phenotypic variation of kernel area (KA), kernel width (KW), kernel length (KL) and thousand-kernel weight (TKW). The marker 1139297 was related to both the KL and KA traits. Only six DArT markers were close to known QTLs. The parent SHW-L1 carried eight favored alleles, while other seven favored alleles were derived from elite common wheat cultivars. These QTLs, identified in elite breeding lines, should help us understand the kernel morphology trait better, and to provide germ-plasm for breeding new wheat cultivars for Qinghai Province or other regions.

In this study, the cDNA of homocysteine S-methyltransferase was isolated from Aegilops tauschii Coss., with the gene accordingly designated as AetHMT1. Similar to other methyltransferases, AetHMT1 contains a GGCCR consensus sequence for a possible zinc-binding motif near the C-terminal and a conserved cysteine residue upstream of the zinc-binding motif. Analysis of AetHMT1 uncovered no obvious chloroplast or mitochondrial targeting sequences. We functionally expressed AetHMT1 in Escherichia coli and confirmed its biological activity, as evidenced by a positive HMT enzyme activity of 164.516 ± 17.378 nmol min-1 mg-1 protein when catalyzing the transformation of L-homocysteine. Compared with the bacterium containing the empty vector, E. coli harboring the recombinant AetHMT1 plasmid showed much higher tolerance to selenate and selenite. AetHMT1 transcript amounts in different organs were increased by Na2SeO4 treatment, with roots accumulating higher amounts than stems, old leaves and new leaves. We have therefore successfully isolated HMT1 from Ae. tauschii and characterized the biochemical and physiological functions of the corresponding protein.

Purple pericarp is an interesting and useful trait in Triticum aestivum, but the molecular mechanism behind this phenotype remains unclear. The allelic variation in the MYB transcriptors is associated with the phenotype of pigmented organs in many plants. In this study, a MYB transcription factor gene, TaMYB3, was isolated using homology-based cloning and a differentially expressed gene mining approach, to verify the function of the MYB transcriptor in the purple pericarp. The coding sequence of TaMYB3 in cultivar Gy115 was the same as that in cultivar Opata. TaMYB3 was localized to FL0.62–0.95 on chromosome 4BL. The TaMYB3 protein contains DNA-binding and transcription-activation domains, and clustered on a phylogenetic tree with the MYB proteins that regulates anthocyanin and proanthocyanin biosynthesis. TaMYB3 localized in the nuclei of Arabidopsis thaliana and wheat protoplasts after it was transiently expressed with PEG transformation. TaMYB3 induced anthocyanin synthesis in the pericarp cells of Opata in the dark in collaboration with the basic helix–loop–helix protein ZmR, which is also the function of ZmC1. However, TaMYB3 alone did not induce anthocyanin biosynthesis in the pericarp cells of the white grain wheat cultivar Opata in the light after bombardment, whereas the single protein ZmR did. Light increased the expression of TaMYB3 in the pericarp of Gy115 and Opata, but only induced anthocyanin biosynthesis in the grains of Gy115. Our results extend our understanding of the molecular mechanism of the purple pericarp trait in T. aestivum.

Red coleoptile is an easily observed trait in Triticum aestivum and can provide some protection against stress. Here, TaMYB-A1 or TuMYB-A1, homologous to TaMYB-D1, which controls red coleoptile formation in the common wheat cultivar ‘Gy115’, was isolated from eight T. aestivum and 34 T. urartu cultivars. The genome sequence of TaMYB-A1 was 867 bp with an intron of 93 bp, which was similar to the MYBs regulating anthocyanin biosynthesis in T. aestivum but different from other MYB transcription factors regulating anthocyanin biosynthesis. TaMYB-A1 had an integrated DNA-binding domain of 102 amino acids and a transcriptional domain of 42 amino acids, which was responsible for regulating anthocyanin biosynthesis. TaMYB-A1 was assigned to the same branch as the MYBs regulating anthocyanin biosynthesis in a phylogenetic tree. A transient expression analysis showed that TaMYB-A1 induced ‘Opata’ coleoptile cells to synthesize anthocyanin with the help of ZmR. A non-functional allele of TaMYB-a1 existed in common wheat cultivars containing rc-a1. One single nucleotide was deleted 715 bp after the start codon in TaMYB-a1 compared with TaMYB-A1. The deletion caused a frame shift mutation, destroyed the DNA transcription activator domain, and resulted in TaMYB-a1 losing its ability to regulate anthocyanin biosynthesis in ‘Opata’ coleoptile cells. Those cultivars with functional TaMYB-A1 or TuMYB-A1 have red coleoptiles. The isolation of TaMYB-A1 should aid in understanding the molecular mechanisms of coleoptile traits in T. aestivum.

Red coleoptile is an easily observed agronomic trait of wheat and has been extensively studied. However, the molecular mechanism of this trait has not yet been revealed. In this study, the MYB gene TaMYB-D1 was isolated from the wheat cultivar ‘Gy115’, which possesses red coleoptiles. This gene resided at the short arm of the homoelogous group 7 chromosomes. TaMYB-D1 was the only gene expressed in the coleoptiles of ‘Gy115’ and was not expressed in ‘Opata’ and ‘CS’, which have uncoloured coleoptiles. Phylogenetic analysis placed TaMYB-D1 very close to ZmC1 and other MYB proteins regulating anthocyanin biosynthesis. The encoded protein of TaMYB-D1 had an integrated DNA binding domain of 102 amino acids and a transcription domain with 42 amino acids, similar to the structure of ZmC1. Transient expression analysis in onion epidermal cells showed that TaMYB-D1 was located at the plant nucleus, which suggested its role as a transcription factor. The expression of TaMYB-D1 was accompanied with the expression of TaDFR and anthocyanin biosynthesis in the development of the coleoptile of ‘Gy115’. Transient expression analysis showed that only TaMYB-D1 induced a few ‘Opata’ coleoptile cells to synthesize anthocyanin in light, and the gene also induced a colour change to red in many cells with the help of ZmR. All of these results suggested TaMYB-D1 as the candidate gene for the red coleoptile trait of ‘Gy115’.

A solvothermal reaction of GdCl3·6H2O, H6TPPS, and histidine led to the formation of a novel gadolinium tetra(4-sulfonatophenyl)porphyrin–amino acid hybrid, namely, {[Gd(His)(H2O)][Gd(H3O)3](H2TPPS)2} n ·3nH2O (1) [His = histidine; H6TPPS = tetra(4-sulfonatophenyl)porphyrin]. The molecular structure of complex 1, which was determined by single-crystal X-ray diffraction technique, shows that the porphyrin macrocycle is saddle-distorted and its center is non-metalated. The gadolinium ions show two kinds of coordination geometry, i.e., a distorted nine-coordinated monocapped square antiprism and a contorted square antiprism. Complex 1 features a three-dimensional structure which is constructed from the gadolinium ions connecting the porphyrin moieties together. The photoluminescence study reveals that it displays an emission in the red region. The cyclic voltammetry/differential pulse voltammetry, FT-IR, and UV–Vis of complex 1 were also investigated in detail. A gadolinium tetra(4-sulfonatophenyl)porphyrin–amino acid hybrid was prepared. It displays an emission in the red region

A novel lanthanide porphyrin [TbIII(H2TPPS)IV·H3O·2H2O] n (1) (H2TPPS = tetra(4-sulfonatophenyl)porphyrin) has been synthesized through a hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. Complex 1 is characterized by a three-dimensional porous open framework with the terbium atom coordinated by eight oxygen atoms to yield a distorted square anti-prism. TG–DTA measurements reveal that complex 1 is thermally stable up to 400 °C. Photoluminescence investigations show that complex 1 has an emission in the red region with a quantum yield of 1.7 % and a lifetime of 341 μs. CV–DPV studies discover one reductive potential of −0.36 V and one quasi-reversible wave with E 1/2 = −0.82 V.

A gadolinium compound [Gd(TPPS)] n ·nH3O (1) (TPPS = tetra(4-sulfonatophenyl)porphyrin) was synthesized by a hydrothermal reaction. Compound 1 was characterized by FT-IR, UV–vis spectra, fluorescence, quantum yield, luminescence lifetime, CV and X-ray diffraction analyses. Compound 1 features a three-dimensional (3-D) porous open framework with lattice water molecules residing at the voids. The 3-D framework is comprised of TPPS moieties and Gd3+ nodes. Photoluminescence measurements reveal that compound 1 exhibits a sharp emission band in the red region with an emission quantum yield being of 5.8 %. Nanosecond transient spectra discover that the fluorescence lifetime of 1 is 11.7 ns. The voltammetric behavior of 1 displays one reduction and two oxidation potentials at −1.75, −0.71 and −1.07 V, respectively. A gadolinium compound was synthesized via a hydrothermal reaction. It features a 3-D porous open framework which is comprised of TPPS moieties and Gd3+ nodes. It exhibits a sharp emission band in the red region with an emission quantum yield being of 5.8 % and a fluorescence lifetime being of 11.7 ns. The CV displays one reduction and two oxidation potentials.

Two viologen(4,4′-bipyridinium)-based cadmium compounds (MQ)(CdI4) (1) and (EQ)(CdI4) (2) (MQ = CH3-4,4′-H2bipy-CH3, EQ = CH3CH2-4,4′-H2bipy-CH2CH3, bipy = bipyridine), in which the MQ and EQ were generated in situ, have been prepared via solvothermal reactions and structurally characterized by single-crystal X-ray diffraction. Both compounds are characteristic of an isolated (0D) structure with the cadmium ions coordinating to four iodine atoms to form a slightly distorted tetrahedron. In compound 1, the MQ cations and CdI4 2− anions link to each other through abundant hydrogen-bonding interactions to construct a 2D supramolecular layer, while compound 2 still exhibits 0D structure because it has only two hydrogen-bonding interactions. Photoluminescent studies reveal that both compounds display an emission in the green region. Theoretical study reveals that the emissions can be ascribable to metal-to-ligand charge transfer (MLCT) and ligand-to-metal charge transfer (LMCT) for 1 and 2, respectively. The spectral data of FT-IR are also reported in this work. Two viologen-based cadmium compounds with the MQ and EQ generated in situ have been synthesized by solvothermal reactions. Both compounds display broad and strong photoluminescent emission bands in the green region. Theoretical investigation reveals that the emissions are attributed to MLCT and LMCT, respectively.

A new compound of [Cu8(Metz)9](OH)·xH2O (x≈3) (1) (Metz = 5-Methyltetrazole) has been prepared and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The crystal is of hexagonal, space group P63/m with a = b = 13.988(1) A, c = 16.309(2) A, α = β = 90°, γ = 120°, V = 2 763.5 (4) A3, Mr = 1327.13, D c = 1.595 g cm−3, Z = 2, F(000) = 1 316, μ = 3.076 mm−1, the final R = 0.0494 and wR = 0.1532 for 1,731 observed reflections (I > 2σ(I)). In this compound, the [(CuII)2(CuI)6(Metz)9]+ cationic clusters are connected together through CuI cations and Metz ligands and result in a three-dimensional framework. Remarkable, three-dimensional intersecting channels exist in it. The variable temperature magnetic investigations indicate that 1 exhibits typical antiferromagnetic behaviors. N2 gas adsorption measurements at 77 K showed that compound 1 possesses permanent porosities.

A new compound of CuCl(QOA)(H2O) (1) [QOA = (8-quinolinyloxy)acetate] has been prepared and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The crystal is of orthorhombic, space group P212121 with a = 5.364(1) A, b = 13.876(3) A, c = 15.435(3) A, V = 1,148.8(4) A3, Mr = 319.19, Dc = 1.846 g cm−3, Z = 4, F(000) = 644, μ = 2.138 mm−1, flack parameter = 0.00(17), the final R = 0.0311 and wR = 0.0646 for 2,179 observed reflections (I > 2σ(I)). Compound 1 consists of one-dimensional helical chains deriving from CuCl(QOA)(H2O) units linked by hydrogen bonds and further extend into a 3D supramolecular structure through Van der Waals interactions, and it exhibits strong luminescent emission at room temperature.

The first example of isonicotinic acid compounds with infinite mercury halide chains, [HgCl2(C6NO2H5)]nn[HgCl2]n(C6NO2H5) (1), was synthesized through hydrothermal reactions and structurally characterized by X-ray single crystal diffraction. Compound 1 features a one-dimensional (1-D) motif, based on infinite 1-D [HgCl2(C6NO2H5)]n chains, neutral HgCl2 moieties and isolated isonicotinic acid molecules. The [HgCl2(C6NO2H5)]n chains, HgCl2 moieties and isonicotinic acid molecules are interlinked by hydrogen bonds and π-π interactions to give a two-dimensional supramolecular layer. Photoluminescent investigation reveals that the title compound exhibits a strong emission in blue region. The emission band is identified as the π -π* transitions of the isonicotinic acid moieties.

The title complex, (N,N′-dimethyl-4,4′-bipyridinium)[Cd2(μ 2-Cl)4Cl2]n (1), in which the N,N′-dimethyl-4,4′-bipyridinium was generated in situ, was synthesized via hydrothermal reaction. X-Ray diffraction analysis revealed that the structure of 1 consisted of MV 2+ (MV 2+ = N,N′-dimethyl-4,4′-bipyridinium) cationic moieties and infinite [Cd2(μ 2-Cl)4Cl2]n anionic chains. The cadmium atom was bound by one terminal chlorine atom and four μ 2-bridging chlorine atoms, yielding a slightly distorted triangular bipyramid. Photoluminescent investigation revealed that the complex displayed an emission in greenish blue region.

A new compound (MQ)(CdBr4) (1; MQ2+ = N-Me-4,4′-bipyridinium), in which the MQ2+ was generated in situ, has been synthesized via hydrothermal reaction. The title compound features an isolated structure, based on discrete MQ2+ moieties and tetrahedral cadmium atoms terminally coordinated by four bromine atoms. The MQ2+ moieties and tetrabromo-cadmium dianions are linked via hydrogen bonds. Photoluminescent investigation reveals that the title compound displays a strong blue-light emission, which is attributed to a ligand-to-ligand charge-transfer (LLCT; from the HOMO of the bromine atoms to the LUMO+1 of the MQ2+ moieties) mechanism probed by molecular orbital (MO) calculations.

The title complex, [Nd(C6NO2H5)3(H2O)2] n n[ZnCl4]·nCl·2.5nH2O (1), was obtained by hydrothermal reactions and structurally characterized by X-ray diffraction. The crystal structure analysis reveals that the title complex is characteristic of a novel polycationic [Nd(C6NO2H5)3(H2O)2] n 3n+ one-dimensional chain-like structure.