Zhao-Ji Li

Synthesis, Structure, and Luminescent Properties of Hybrid Inorganic-Organic Framework Materials Formed by Lead Aromatic Carboxylates: Inorganic Connectivity Variation from 0D to 3D

The hydro(solvo)thermal reactions of Pb(OAc)(2).3H(2)O with the aromatic carboxylic ligands 1,3,5-benzenetricarboxylic and 1,4-, 1,2-, and 1,3-benzenedicarboxylic acids (1,3,5-H(3)BTC; 1,4-, 1,2-, and 1,3-H(2)BDC) have yielded a family of inorganic-organic framework materials: [Pb(2)(1,3,5-BTC)(mu(3)-OH)(H(2)O)](n) (Iota), [NaPb(1,3,5-BTC)(H(2)O)](n) (IotaIota), [Pb(1,4-BDC)](n) (IotaIotaIota), [Pb(5)(1,2-BDC)(4)(OAc)(2)](n) (IV), and {[Pb(5)(1,3-BDC)(5)(H(2)O)(2)](2).H(2)O}(n) (V). These complexes have been characterized by means of single-crystal X-ray diffraction, X-ray powder diffraction, thermogravimetric analysis-mass spectrometry, and photoluminescence spectra. They are all three-dimensional structures except for two-dimensional IV. Topology analysis reveals that complexes I an V represent rare (4,8)-connected flu and (3,4)-connected zeolite-like nets, respectively. The five complexes exhibit diverse inorganic connectivity, including a 0D Pb(4)O(16) cluster for I, a 1D Pb-O-Pb chain for II, a 2D Pb-O-Pb network for III and IV, and an unprecedented 3D Pb-O-Pb framework for V. And the diversity in inorganic arrays leads to differences in luminescent properties of these complexes.

Topology Analysis and Nonlinear-Optical-Active Properties of Luminescent Metal-Organic Framework Materials Based on Zinc/Lead Isophthalates

Two 3D Zn(II) and Pb(II) isophthalates, [Zn(ip)]n (1) and [Pb4(mu4-O)(ip)3(H2O)]n (2) (H2ip = isophthalic acid), have been prepared under hydro(solvo)thermal conditions and characterized by single-crystal X-ray diffraction. The two complexes crystallize in different space groups (P4(3)2(1)2 for 1 and P2(1)/c for 2) and have different bridging modes of the ip ligand. The 3D framework of 1 is constructed by the interconnection of ZnO4 polyhedra via ip ligands, which represents a chiral net with PtS-type topology. In contrast, complex 2 is formed by the combination of Pb4O-cluster secondary building units and has a novel (3.4.5)(3(2).4(5).5(6).6(7).7(2)) topology, which is the first ever example of a (3,7)-connected net. Complex 1 displays a second harmonic generation efficiency of about 1.5 times that of KH2PO4. Optical properties and thermal stabilities of the two complexes have been studied. Additionally, the calculations of band structure and density of states of 1 have also been performed with the density functional theory method.

Synthesis, Structure, and Physical Properties of a New Anions-Controlled Cd(II)-Guanazole (3,5-Diamino-1,2,4-triazole) Hybrid Family

Nine members of a new anions-controlled Cd(II)-guanazole (3,5-diamino-1,2,4-triazole=Hdatrz) hybrid family, that is, [Cd3(datrz)6(H2O)2] (1), [Cd3(datrz)4F2] (2), [Cd5(datrz)4Cl4(OH)2] (3), [Cd5(datrz)4Br4(OH)2] (4), [Cd3(datrz)2(SO3)2].(H2O) (5), [Cd3(datrz)2(O2CMe)4] (6), [Cd(datrz)(O2CEt)] (7), [Cd(Hdatrz)(O2CtBu)2] (8), and [Cd(Hdatrz)2(H2Edta)] (9) have been synthesized by exploiting hydrothermal reactions of guanazole with suitable cadmium salts under appropriate reaction conditions. With effective control of inorganic or organic anions, the coordination diversity of the guanazole ligand in 1-9 manifests an unprecedented enrichment with five bridging modes varying from bidentate to quadridentate, two of which are first reported. Compound 1 is the first reported three-dimensional chiral complex constructed from the guanazole ligand which adopts a novel N1, N2, amino N-bridging mode. Halogen anions F-, Cl-, and Br- controlled compounds 2-4 are all three-dimensional, with their guanazole ligands possessing another novel quadridentate bridging mode. Sulfite anions controlled compound 5 displays a three-dimensional network with peculiar cage-like hexnuclear cadmium clusters. As for organic anions, low dimensional structures have been found for alkylcarboxylate anions MeCO2-, EtCO2-, and tBuCO2- controlled compounds 6, 7, and 8 (two-dimensional) and for H2Edta2- controlled compound 9 (zero-dimensional), and their guanazole ligands manifest low coordination numbers as well. These hybrid materials also present interesting structure-induced physical properties. The chiral compound 1 exhibits the second-order nonlinear optical properties at room temperature. Compounds 2-9 except 6 all exhibit photoluminescence of blue fluorescent emissions in the solid state at ambient temperature, which may be assigned to the intraligand pi-pi* transitions. Some structure related red or blue emission shifts have been investigated. Thermal studies show that most compounds of this study possess a high thermal stability.

Expression of the plasma membrane H+-ATPase gene in response to salt stress in a rice salt-tolerant mutant and its original variety

Abstract Plasma membrane (PM) H+-ATPase plays an important role in the establishment and maintenance of ion homeostasis. To investigate its expression in the rice salt-tolerant mutant M-20 and the original variety 77–170 during salt stress, a cDNA fragment corresponding to the PM H+-ATPase gene was obtained by PCR from rice japonica variety 77–170 and designated as OSA3. Sequence analysis of OSA3 revealed its high homology with two other published PM H+-ATPase genes, OSA1 and OSA2, in rice. Southern-blot analysis detected a RFLP between M-20 and 77–170, and one copy of the OSA3 gene was mapped to a position on rice chromosome 12 where a salt tolerance QTL was closely located. The expression of the PM H+-ATPase gene, as revealed by the OSA3 fragment, was compared between M-20 and 77–170. The results demonstrated that M-20 shoots accumulated less transcripts than 77–170 shoots at a later stage of salt treatment, and M-20 showed high expression at 300 mM NaCl while 77–170 reached its maximum at 200 mM NaCl. In roots, the difference in the level of the PM H+-ATPase gene expression between stressed and non-stressed plants was substantially greater in M-20 than that in 77–170. The relative abundance of PM H+-ATPase gene transcripts in M-20 roots may indicate the active role of this gene in the strict control of Na+ and Cl+ uptake into root symplast and apoplast, and further translocation into the shoot, hence leading to the reduced gene expression of M-20 shoots under salt-stress conditions.

Role of molar-ratio, temperature and solvent on the Zn/Cd 1,2,4-triazolate system with novel topological architectures

Five members of the Zn/Cd triazolate family, [Zn(TAZ)(OAc)]n (1), [Zn4(TAZ)6(OAc)2]n (2), [Cd3Cl3(TAZ)3(DMF)2]n (3), [CdCl2(TAZ)]n·n(H2O) (4) and [Cd2Cl(μ4-AmTAZ)2(μ-AmTAZ)]n (5), have been synthesized from TAZ/AmTAZ and corresponding metal salts, where TAZ, AmTAZ and DMF are 1,2,4-triazole, 3-amino-1,2,4-triazole and N,N′-dimethylformamide, respectively. X-ray analysis shows that all compounds except 4 manifest interesting 3D frameworks with novel topologies. Compounds 1 and 2 are temperature-and-solvent controlled assemblies and possess 3D (3,4,6)-connected (3.72)2(32.4.73)(32.4.76.86) topology and 3D (3,6)-connected (4.82)3(83)(46.86.123) topology, respectively. However, compounds 3 and 4 are molar-ratio-dependent compounds. The framework of 3 is a 3D (3,4,5)-connected one with (4.102)(4.62)2(43.62.8)2(64.106) topology, in which the 1D channels are filled with coordinated DMF, while only a 1D chain-like motif is formed in 4. In addition, a 3D (4,6)-connected (3.42.52.6)2(32.42.54.65.72)(32.44.54.64.7) topology is observed in the framework of 5, where AmTAZ is used instead of TAZ in the syntheses of compounds 1–4. Solid state measurements reveal that all these coordination polymers are thermostable and luminescent under ambient conditions.

Differential accumulation of the S-adenosylmethionine decarboxylase transcript in rice seedlings in response to salt and drought stresses

Abstract Differences in gene expression between salinity-stressed and normally grown rice seedlings were compared by using the differential display (DD) technique. One DD-derived cDNA clone was characterized as a partial sequence of the rice S-adenosylmethionine decarboxylase (SAMDC) gene by sequence analysis and a homology search of GenBank databases. The full-length cDNA for the rice SAMDC gene, designated SAMDC1, was further isolated by the RT-PCR approach and was found to be different from another rice SAMDC gene released in GenBank. Comparison of the deduced polypeptide of SAMDC1 with SAMDC proteins from other plant species revealed several homologous regions, in particular the conserved proenzyme cleavage site and the putative PEST domain. Southern blot analysis indicated that the SAMDC1 gene was present as a single-copy sequence in the rice genome. Northern hybridization showed that the transcript of SAMDC1 was differentially accumulated in rice seedlings in response to salinity, drought and exogenous abscisic acid (ABA) stresses. Furthermore, levels of the SAMDC1 transcript under saline conditions were compared between a salt-tolerant japonica rice variety, Lansheng, and a salt-sensitive japonica rice variety, 77–170. It was observed that elevation in the level of the SAMDC1 transcript occurred earlier in Lansheng than in 77–170 when both were affected by salinity stress. In addition, relative to the control, higher levels of the SAMDC1 transcript were detected in Lansheng under low salt conditions or salt-stressed for shorter times, and also in 77–170 under high salt conditions or salt-stressed for prolonged times. The results suggest that expression of the SAMDC1 gene in seedlings is positively correlated with the salt tolerance of rice.

Organically templated metal–organic framework with 2-fold interpenetrated {33.59.63}-lcy net

A new organic cation templated Zn(II) complex (Et3NH)[Zn4(ip)3(bta)3] (, ip = isophthalate, Hbta = benzotriazole) which consists of plate-like Zn4(bta)3 units bridged by ip ligands is reported; it is the first example of a 6-connected uninodal {3(3).5(9).6(3)}-lcy net which has never been observed previously in MOFs but has been theoretically anticipated.

Genomic in situ hybridization (GISH) analyses of Thinopyrum intermedium, its partial amphiploid Zhong 5, and disease-resistant derivatives in wheat

Abstract Genomic in situhybridization (GISH) to root-tip cells at mitotic metaphase, using genomic DNA probes from Thinopyrum intermedium and Pseudoroegneria strigosa, was used to examine the genomic constitution of Th. intermedium, the 56-chromosome partial amphiploid to wheat called Zhong 5 and disease-resistant derivatives of Zhong 5, in a wheat background. Evidence from GISH indicated that Th. intermedium contained seven pairs of St, seven JS and 21 J chromosomes; three pairs of Th. intermedium chromosomes with satellites in their short arms belonging to the St, J, J genomes and homoeologous groups 1, 1, and 5 respectively. GISH results using different materials and different probes showed that seven pairs of added Th. intermedium chromosomes in Zhong 5 included three pairs of St chromosomes, two pairs of JS chromosomes and two pairs of St-JS reciprocal tanslocation chromosomes. A pair of chromosomes, which substituted a pair of wheat chromosomes in Yi 4212 and in HG 295 and was added to 21 pairs of wheat chromosomes in the disomic additions Z1, Z2 and Z6, conferred BYDV-resistance and was identical to a pair of St-JS tanslocation chromosomes (StJS) in Zhong 5. The StJS chromosome had a special GISH signal pattern and could be easily distinguished from other added chromosomes in Zhong 5; it has not yet been possible to locate the BYDV-resistant gene(s) of this translocated chromosome either in the St chromosome portion belonging to homoeologous group 2 or in the JS chromosome portion whose homoeologous group relationship is still uncertain. Among 22 chromosome pairs in disomic addition line Z3, the added chromosome pair had satellites and belonged to the St genome and homoeologous group 1. Disomic addition line Z4 carried a pair of added chromosomes which was composed of a group-7 JS chromosome translocated with a wheat chromosome; this chromosome was different to 7 Ai-1, but was identical to 7 Ai-2. The leaf rust and stem rust resistance genes were located in the distal region of the long arm, whereas the stripe rust resistance gene(s) was located in the short arm or in the proximal region of the long arm of 7 Ai-2. A pair of JS-wheat translocation chromosomes, which originated from the WJS chromosomes in Z4, was added to the disomic addition line Z5; the added chromosomes of Z5 carried leaf and stem rust resistance but not stripe rust resistance; Z5 is a potentially useful source for rust resistance genes in wheat breeding and for cloning these novel rust-resistant genes. GISH analysis using the St genome as a probe has proved advantageous in identifying alien Th. intermedium in wheat.

Scorpion-shaped carboxylate ligand tailored molecular square, bilayer, self-threading and (3,6)-connected nets

A novel designed scorpion-shaped 5-oxyacetateisophthalic acid (H3OABDC) was used to construct a series of luminescent metal–organic frameworks, namely [Zn2(HOABDC)2(phen)2(H2O)2]n·nH2O (1), [Zn2(OABDC)(4,4′-bipy)(μ2-OH)(H2O)]n·4/3nH2O (2), [Cd3(OABDC)2(4,4′-bipy)4(H2O)4]n·2nH2O (3), [Cd2(OABDC)(phen)2(μ3-OH)]n·1/3nH2O (4), and [Zn8(OABDC)4(2,2′-bipy)4(μ2-OH)4]n·2nH2O (5) (bipy = bipyridine, phen = 1,10-phenanthroline). Complex 1 features a discrete molecular square and π–π and C–H⋯π interactions between molecular squares give rise to a 2D sheet. Complex 2 shows an unusual 2D bilayer architecture with (3,5)-connected topology. A prominent structural feature in 3 is the self-threading 2D layered structure. Both 4 and 5 exhibit (3,6)-connected topology. In 4, an extraordinary folded four-step-ladder Cd4(OH)2 unit acts as 6-connected node and the framework is 2D (3,6)-connected net. While in 5, the Zn2(OH) unit adopts octahedral geometry and the whole framework features a 3D (3,6)-connected rutile (rtl) topology. Photoluminescence studies revealed that these complexes are interesting blue, green and orange luminescent materials. The thermal stabilities of these complexes are also discussed.

A rare metal–organic 3D architecture with a pseudo-primitive cubic topology with double edges constructed from a 12-connected SBU

The hydrothermal assembly of CdCl2 with isophthalatic acid (H2ip) and 1,3-bis(4-pyridyl)propane (bpp) yielded a novel 3D coordination polymeric complex, [Cd4(ip)4(bpp)2]n (1), which presents an interesting non-interpenetrated pseudo-primitive cubic (pcu) topology with double edges constructed from a 12-connected SBU.