RNA interference of NADPH-cytochrome P450 reductase increases the susceptibility of Aphis gossypii Glover to sulfoxaflor.

NADPH-cytochrome P450 reductase (CPR) is essential for the detoxification of endogenous and exogenous substances mediated by cytochrome P450. While several insect CPRs have been found to be associated with insecticide resistance, the CPR of Aphis gossypii has not been characterized, and its functional role in insecticide resistance remains undefined. In this study, we cloned and characterized the full-length sequence of A. gossypii CPR (AgCPR). The deduced amino acid sequence of AgCPR contains all conserved domains of CPR, which shows high similarity to other insect CPRs and was clustered into a same branch of aphids according to phylogenetic analysis. The transcript of AgCPR was present in all developmental stages, with the highest expression in the adult stage. Furthermore, the expression of AgCPR could be induced by sulfoxaflor, a commonly used insecticide, in a time- and dose-dependent manner. Further silencing of AgCPR by feeding dsRNA significantly increased the susceptibility of A. gossypii to this insecticide. These findings suggest that AgCPR may play a significant role in the susceptibility of A. gossypii to sulfoxaflor and in the development of P450-mediated resistance to sulfoxaflor.

Physicochemical and Digestible Properties of Parboiled Black Rice With Different Amylose Contents.

The varieties of black rice with different amylose contents (waxy; medium-amylose: 16.03%; high-amylose: 27.14%) were parboiled and then evaluated for physicochemical and digestible properties. The color, crystalline structure, and swelling property of parboiled rice were analyzed, and the water molecular mobility, texture, and starch digestibility of cooked parboiled rice were determined. The color of black rice was only slightly changed after the parboiling treatment. The crystalline structures of waxy and medium-amylose rice were severely damaged by the parboiling treatment, while the highly crystalline structure was retained in parboiled high-amylose rice. During heating in water, parboiled high-amylose rice had a lower water absorption ratio (WAR) and volume expansion ratio (VER) than the other two varieties. After cooking, parboiled high-amylose rice had higher water molecular mobility and harder texture compared with the other two varieties. Cooked parboiled high-amylose rice contained higher content of resistant starch than cooked parboiled waxy and medium-amylose rice.

UDP-Glycosyltransferases from the UGT344 Family Are Involved in Sulfoxaflor Resistance in Aphis gossypii Glover.

UDP-glycosyltransferases (UGTs) are major phase II detoxification enzymes that catalyze the transfer of glycosyl residues from activated nucleotide sugars to acceptor hydrophobic molecules and play very important roles in the biotransformation of various endogenous and exogenous compounds. Our previous studies demonstrated that UGTs participated in the detoxification of insecticides in Aphis gossypii. However, the potential roles of UGTs in A. gossypii resistance to sulfoxaflor are still unclear. In this study, two inhibitors of UGT enzymes, sulfinpyrazone and 5-nitrouracil, significantly increased the toxicity of sulfoxaflor to a resistant strain of A. gossypii, whereas there were no synergistic effects in the susceptible strain. Based on the transcriptome sequencing results, the expression levels of 15 UGTs were analyzed by quantitative real-time PCR, and we found that seven UGT genes were highly over-expressed in a sulfoxaflor-resistant strain compared to the susceptible strain, including UGT344B4, UGT344C5, UGT344A11, UGT344A14, and UGT344L2. Further suppressing the expression of UGT344B4, UGT344C5, and UGT344A11 by RNA interference significantly increased the sensitivity of resistant aphids to sulfoxaflor, indicating that the overexpression of UGT genes is potentially associated with sulfoxaflor resistance. These results could provide valuable information for further understanding the mechanisms of insecticide resistance.

Toxicity and sublethal effects of two plant allelochemicals on the demographical traits of cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae).

Plant allelochemicals are a group of secondary metabolites produced by plants to defend against herbivore. The mortality of two plant allelochemicals (tannic acid and gossypol) on the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), were investigated using feeding assays and the sublethal effects were evaluated using the age-stage, two-sex life table approach. Tannic acid and gossypol have deleterious effects on A. gossypii, and as the concentrations increased, the mortality of cotton aphid increased. The life history traits of A. gossypii including the developmental duration of each nymph stage, the longevity, oviposition days, total preadult survival rate and adult pre-oviposition period were not significantly affected by sublethal concentration of tannic acid (20 mg/L) and gossypol (50 mg/L), while the population parameters (r, λ and R0) were significantly affected by these two plant allelochemicals. Furthermore, tannic acid can increase the pre-adult duration time and TPOP but reduce the fecundity of A. gossypii significantly compared to the control and gossypol treatment groups. These results are helpful for comprehensively understanding the effects of plant allelochemicals on A. gossypii.

Fitness costs of sulfoxaflor resistance in the cotton aphid, Aphis gossypii Glover.

Aphis gossypii Glover is an economically important pest of numerous crops throughout the world. Some field populations of A.gossypii in China have developed moderate level of resistance to sulfoxaflor, a newly released sulfoximine insecticide for management of sap-feeding pests. To evaluate the effect of sulfoxaflor resistance on the fitness cost of A. gossypii, the life history traits of sulfoxaflor-resistant strain (SulR) and an isogenic susceptible strain (SS) were compared using the age-stage, two-sex life table approach. The results showed that the resistant strain had a reduction in fitness (relative fitness = 0.917), along with significantly decreases in longevity, fecundity, net reproductive (R0), mean generation time (T) and gross reproductive rate (GRR). Compared to the susceptible strain, SulR strain showing a shorter developmental duration of each nymph instar stage. Moreover, the adult pre-oviposition period (APOP) and total preoviposition period (TPOP) of SulR strain were also significantly shorter than that of the susceptible strain. Investigation of six development and reproduction related genes indicated that EcR, USP and JHBP were overexpressed in the SulR strain, while the mRNA transcript level of Vg was decreased significantly compared to the susceptible strain. These results suggest that there is a fitness cost associated with sulfoxaflor resistance in A. gossypii and the different expression of EcR, USP, JHBP, and Vg may play very important role in this trade-off.

Overexpression of multiple cytochrome P450 genes associated with sulfoxaflor resistance in Aphis gossypii Glover.

Sulfoxaflor is the first commercially available sulfoximine insecticide, which exhibits highly efficacy against many sap-feeding insect pests and has been applied as an alternative insecticide against cotton aphid in China. This study was conducted to investigate the risk of resistance development, the cross-resistance pattern and the potential resistance mechanisms of sulfoxaflor in Aphis gossypii. A colony (SulR strain) of A. gossypii with 245-fold resistance, originated from Xinjiang field population, was established by continuous selection using sulfoxaflor. The SulR strain has developed cross-resistance to imidacloprid (80.8-fold), acetamiprid (19.3-fold), thiamethoxam (10.0-fold), and flupyradifurone (107.5-fold), while no cross-resistance was detected to malathion, omethoate, bifenthrin, methomyl, and carbosulfan. Piperonyl butoxide and S, S, S-tributyl phosphorotrithioate could significantly increase the toxicity of sulfoxaflor to the SulR strain by 5.99- and 4.18-fold, respectively, whereas no synergistic effect with diethyl maleate was observed. The activities of P450s and carboxylesterase were significantly higher in the SulR strain than that in the SS strain. Further gene expression determination demonstrated that nine P450 genes were significantly increased in SulR strain and suppression the expression of CYP6CY13 and CYP6CY19 by RNAi significantly increased the susceptibility of SulR adult aphids to sulfoxaflor. These results demonstrated that the enhancing detoxification by cytochrome P450 monooxygenase may be involved in A.gossypii resistance to sulfoxaflor.

Controllable acidophilic dual-emission fluorescent carbonized polymer dots for selective imaging of bacteria.

Fluorescent materials can be powerful contrast agents in photoelectric devices and for bioimaging. As emerging fluorescent materials, carbonized polymer dots (CPDs) with high quantum yields (QYs), long-wavelength emission and multiple functions are highly desired. Despite great progress in the synthetic methods and QYs of CPDs, multiple emission of CPDs is challenging. Therefore, we developed CPDs with dual-emission fluorescence in terms of inherent blue and red emission. In addition, CPDs with sole blue emission (B-CPDs) and red emission (R-CPDs) were synthesized, respectively, by regulating the reaction conditions to control the quantitative structure and emission centers. The absolute QY of R-CPDs in water was 24.33%. These three types of CPDs with dual/sole emission could be used in optoelectronic and bioimaging applications. With different CPDs coated on a commercially available gallium nitride light-emitting diode chip as a color-conversion layer, LEDs with blue, yellow, and red emission were achieved. Benefiting from the different emission intensities and emission peaks of R/B-CPDs in different pH conditions, they were used (without further modification) to distinguish between Porphyromonas gingivalis, Streptococcus mutans, Escherichia coli and Staphylococcus aureus in dental plaque biofilms (the first time this has been demonstrated). These findings could enable a new development direction of CPDs based on the design of multi-emission centers.

Transgenerational hormetic effects of sublethal dose of flupyradifurone on the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae).

Both inhibitory and stimulatory (known as hormesis) effects of the sublethal flupyradifurone, a butenolide insecticide, on Myzus persicae Sulzer (Hemiptera: Aphididae) were investigated for incorporating it into integrated pest management (IPM). A leaf-dip bioassay showed that flupyradifurone was very toxic against adult M. persicae with a 48 h LC50 of 8.491 mg/L. Using the age-stage two-sex life table approach, we assessed the effects of LC25 of flupyradifurone on adult M. persicae and its progeny (F1 and F2). On the one hand, aphids exposed to flupyradifurone had significantly negative effects on the life history traits acrossing the generations, such as reduced the adult longevity and fecundity of F0, shortened the duration of third instar and fourth instar nymphs, preadult period and the pre-reproductive period of F1, and decreased the reproductive days and adult longevity of F2. On the other hand, stimulatory effects on the duration of pre-adult, adult reproductive days, and reproduction of F1 were observed in the flupyradifurone-treated aphids. Consistently with the stimulation on individual traits, a higher net reproductive rate (R0) of F1 and a shorter mean generation time (T) of F2 were observed in the flupyradifurone-treated aphids, although the other population parameters including the intrinsic rate of increase (r), finite rate of increase (λ) and T of F1 and R0, r and λ of F2 were not significantly affected. These results revealed that adult M. persicae exposed to sublethal concentration of flupyradifurone can induce hormetic effects on F1, and also cause negative effects on F2. Our results would be useful for assessing the overall effects of flupyradifurone on M. persicae and the hormetic effects should take into consideration when use flupyradifurone for control M. persicae.

Three new metal coordination polymers of bifunctional imidazolate/tetrazolate bridges: the only example of a three-dimensional framework based on rare [Co4(µ3-OH)2(µ2-Cl)2]4+ mixed oxo-chloro-clusters.

Three new metal coordination polymers [Ni(µ2-L)2(H2O)2] n (1, HL = 1-tetrazole-4-imidazole-benzene), [Co(µ2-L)2] n (2), and [Co4(µ3-OH)2(µ2-Cl)2(µ5-L)2(µ2-L)2] n ·7nH2O (3) were hydrothermally synthesized and structurally characterized. 1 displays a neutral [Ni(µ2-L)2(H2O)2] n chain built up from the Ni2+ ions bridged by deprotonated L- ligands, while 2 shows another rare neutral [Co(µ2-L)2] n chain based on Co2+ ions connected by two different coordination modes of the L- ligand. 3 exhibits a rare [Co4(µ3-OH)2(µ2-Cl)2]4+ mixed oxo-chloro-cluster-based three-dimensional framework with large elliptical channels, which are filled by unprecedented chilopod [(H2O)7] n chains. Both 1 and 2 show antiferromagnetic behavior, while 3 exhibits unusual spin-canting.

CYP4CJ1-mediated gossypol and tannic acid tolerance in Aphis gossypii Glover.

Cytochrome P450 monooxygenases play a key role in herbivorous pest adaptation to host plants by the detoxification against plant allelochemicals. A new P450 gene (CYP4CJ1) was identified from Aphis gossypii, which displayed a positive response to plant allelochemicals. The transcript levels of CYP4CJ1 could be significantly induced by both gossypol and tannic acid. Knockdown of CYP4CJ1 increased the sensitivity of A. gossypii to these two plant allelochemicals. These results suggest that CYP4CJ1 could be involved in the tolerance of A. gossypii to some plant allelochemicals. Subsequently, we examined the regulatory mechanism of CYP4CJ1 based on the transcriptional and post-transcriptional level. A promoter region from -1422 to -1166 of CYP4CJ1 was identified, which was an essential plant allelochemical responsive region. In addition, miR-4133-3p was found to participate in the regulation of CYP4CJ1 post-transcriptionally. Our results suggest that the transcript abundance of CYP4CJ1, following the exposure of A. gossypii to gossypol and tannic acid can be attributed to both the transcriptional and post-transcriptional regulation mechanisms. These results are important for understanding the roles of P450s in the plant allelochemical tolerance of A. gossypii.

Anti-inflammatory Effects of PMX205 in Mouse Macrophage Periodontitis Model.

BACKGROUND: C5a receptor antagonist PMX205 is a synthetic hexapeptide capable of blocking C5a-C5a receptor (C5aR) axis by simulating C5a active C-terminal amino acid residues. This hexapeptide presents good anti-inflammatory effects in a series of inflammation models. The anti-inflammatory effect of PMX205 on periodontitis is yet to be fully fathomed. OBJECTIVE: To examine the anti-inflammatory effects of PMX205 on RAW264.7 mouse macrophages exposed to gingipain extracts and Porphyromonas gingivalis (P. gingivalis). METHODS: MTT assay was carried out so as to specify the cytotoxicity of PMX205. RAW264.7 cells were co-cultured in vitro with gingipain extracts or P. gingivalis to simulate the periodontitis inflammatory milieu. Real-time quantitative PCR, ELISA and Griess assay were performed in order to detect tumor necrosis factor-α (TNF-α), IL-6, IL-23, nitric oxide (NO), IL-10, transforming growth factor-ß1 (TGF-ß1), andarginase-1 (Arg-1). Furthermore, phagocytosis assay was done to evaluate the phagocytic capacity of RAW 264.7 cells. Finally, western blot analysis was conducted to evaluate myeloid differentiation factor 88 (MyD88). RESULTS: PMX205 increased the expression levels of bacteriostatic substances (NO and IL-23) and anti-inflammatory cytokines (TGF-ß1, IL-10 and Arg-1); however, it reduced the expression levels of proinflammatory cytokines TNF-α and IL-6 once RAW 264.7 macrophages were stimulated via gingipain extracts or P. gingivalis. In addition, PMX205 promoted the macrophage phagocytosis and down-regulated protein expression of MyD88. CONCLUSION: PMX205 has recognizable anti-inflammatory effects in RAW 264.7 cell inflammation model, a finding which probably opens doors to future investigations on new targets for the prevention and treatment of chronic periodontitis.

Reversible "Off-On" Fluorescence of Zn2+-Passivated Carbon Dots: Mechanism and Potential for the Detection of EDTA and Zn2.

Zn2+-passivated carbon dots (named Z-CDs) were synthesized from zinc gluconate for the first time through a one-step pyrolysis treatment. The mechanism of Zn2+-enhanced fluorescence was carefully investigated, and a new strategy to passivate the surfaces of CDs by Zn2+ was proposed. Inspired by the complexation reaction between Zn2+ and ethylenediaminetetraacetic acid (EDTA), a reversible "off-on" fluorescent nanosensor for the detection of EDTA and Zn2+ was constructed based on the depassivation and repassivation of Z-CDs, with a limit of detection as low as 3.2 × 10-7 M and 5.1 × 10-7 M, respectively. The proposed Z-CD-based nanosensor had been further utilized for EDTA and Zn2+ monitoring in tap water with excellent recovery. To the best of our knowledge, this was the first report of a fluorescence-based sensor of EDTA and a turn-on sensor of Zn2+ based on CDs with reversible detection capability. Also, benefiting from the low toxicity of zinc, Z-CDs were applied for multicolor bioimaging and in vitro detection in cells.

Monitoring insecticide resistance and diagnostics of resistance mechanisms in the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) in China.

Myzus persicae (Sulzer) is one of the most serious agricultural pests in China, and management strategies mainly rely on insecticidal treatment. To evaluate the resistance of field populations of M. persicae to seven insecticides, we assessed the susceptibility of 11 field populations collected from eight provinces in China using leaf-dip bioassays. Toxicity assays showed that M. persicae field populations have developed several levels of resistance to each tested insecticide. For pyrethroids, the field populations have developed a high level of resistance to ß-cypermethrin and cypermethrin, while the resistance to bifenthrin is still low. The resistance ratios of field populations to imidacloprid ranged from 1.48 to 52.36, and eight populations have developed moderate to high resistance. Resistance to acetamiprid is low, and only two populations have a moderate level of resistance. Most of the field populations of M. persicae developed moderate to high resistance to methomyl and omethoate. To investigate potential resistance mechanisms, we analyzed the enzyme activity of carboxylesterases, the type of amplified esterase genes, as well as the kdr (L1014F) mutation. All of the field populations exhibited a higher esterase activity compared to the laboratory susceptible strain. An amplified FE4, as well as the L1014F mutation, were also found in all of our experimental field populations. These results provide valuable insight into the current status of insecticide resistance and will prove to be a valuable resource in designing appropriate resistance management strategies for M. persicae in China.

Down regulation of lincRNA-p21 contributes to gastric cancer development through Hippo-independent activation of YAP.

Long intergenic non-coding RNA p21 (lincRNA-p21), known as the direct transcriptional target of p53, was found down-regulated in several human solid tumors. However, little is known about the role of lincRNA-p21 in gastric cancer. The expression levels of lincRNA-p21 in tissue samples and cell lines were detected by qRT-PCR. MGC-803 and MKN-45 cells were transfected with siRNAs targeting lincRNA-p21 or control siRNAs to determine the effect of reduced lincRNA-p21 expression on tumorigenesis. We also overexpressed lincRNA-p21 in MGC-803 cells. Cell proliferation was measured by CCK-8 and Ethynyl-2-deoxyuridine (EdU) incorporation assays. Migration and invasion abilities of cells were measured by wound healing and transwell assay. We demonstrated that lincRNA-p21 was significantly reduced in gastric cancer tissues (p<0.001) compared with that in normal tissues and this lower level of lincRNA-p21 was significantly correlated with higher invasion depth grade (p=0.024), more distant metastasis (p=0.009) and advanced TNM stage (p=0.011). Further study revealed that knock down of lincRNA-p21 could promote malignant behavior of gastric cancer cells and induce epithelial to mesenchymal transition (EMT). Overexpressing lincRNA-p21 showed opposite effects. Moreover, knocking down lincRNA-p21 could elevate the expression of Yes associated protein (YAP), the core effector of Hippo signaling, by elevating mRNA levels and increasing its nucleus translocation instead of the canonical Hippo pathway. Overexpression experiments verified the regulation role of lincRNA-p21 in YAP expression. Collectively, these data suggest that lincRNA-p21 could serve as a potential biomarker and a vital therapeutic target in gastric cancer.

A Series of Lanthanide-Germanate Oxo Clusters Decorated by 1,10-Phenanthroline Chromophores.

A series of lanthanide-germanate oxo clusters, [Ln8(phen)2Ge12(µ3-O)24T12(H2O)16]·2H2O [Ln = Dy (1a) and Er (1b); T = -CH2CH2COO- group; phen = 1,10-phenanthroline], [Ln8(phen)2Ge12(µ3-O)24T12(H2O)16]·2phen·16H2O [Ln = Sm (2a), Eu (2b), and Gd (2c)], and [Ho8(phen)2Ge12(µ3-O)24T12(H2O)14]·2phen·13H2O (3), have been hydrothermally synthesized from the reactions of bis(carboxyethylgermanium sesquioxide) and Ln2O3 with auxiliary phen chromophores. Compounds 1a and 1b consist of cage clusters [Ln8(phen)2Ge12(µ3-O)24T12(H2O)16] and free H2O molecules, where cage clusters are arranged in a CsCl type, while compounds 2a-2c consist of cage clusters [Ln8(phen)2Ge12(µ3-O)24T12(H2O)16], free phen, and free H2O molecules, where cage clusters are arranged in a NaCl type. Compound 3 consists of the one-dimensional neutral chain [Ho8(phen)2Ge12(µ3-O)24T12(H2O)14]n and free H2O molecules. These compounds provide the first examples of p-f heterometallic [Ge-O-Ln] oxo clusters decorated by phen chromophores. The photoluminescent and magnetic properties of all compounds have been investigated.

A P-glycoprotein gene serves as a component of the protective mechanisms against 2-tridecanone and abamectin in Helicoverpa armigera.

P-glycoprotein (P-gp) exists in animals, fungi and bacteria and likely evolved as a defense mechanism against harmful substances. Here a cDNA (4054bp) encoding a putative P-glycoprotein gene from Helicoverpa armigera was cloned and named HaPgp1. This putative HaPgp1 sequence encoded a protein of 1253 amino acids with a molecular mass of approximately 137kDa. qPCR analyses demonstrated that the expression of HaPgp1 was significantly higher in 4th instar larvae when compared to other developmental stages. HaPgp1 transcripts were more abundant in the head and fat bodies than in other tissues. Compared with the control, the expression of HaPgp1 reach a peak at 12h after the treatment by 2-tridecanone in all tissues. However, the expression of HaPgp1 increased from 12h to 48h after treatment with abamectin in all tissues. Immunohistochemistry analyses also verified that 2-tridecanone and abamectin can induce the increase of HaPgp1 expression. RNAi of HaPgp1 significantly raised the mortality rate of larvae treated by 2-tridecanone and abamectin, as compared to control larvae fed with GFP dsRNA. These results illustrate the possible involvement of HaPgp1 as a component of the protective mechanisms to plant secondary chemicals such as 2-tridecanone and to certain classes of insecticides, like abamectin.

RNA interference of Dicer-1 and Argonaute-1 increasing the sensitivity of Aphis gossypii Glover (Hemiptera: Aphididae) to plant allelochemical.

Plant allelochemicals are a group of important defensive agents of plants, which have been documented to be deleterious to insect herbivores. In the present study, we found that the expression level of Dicer-1 was significantly increased when Aphis gossypii adults fed on plant allelochemicals (tannic acid and gossypol) incorporated artificial diets. Consider that miRNAs play great regulatory roles in various biological processes, this suggested that miRNAs may be related to the regulation of enzymes involved in metabolism of plant allelochemicals in A. gossypii. To further reveal the roles of miRNAs in the response of A. gossypii against plant allelochemicals, both Dicer-1 and Argonaute-1, an important component of the RNA-induced silencing complex (RISC) in miRNA pathway, were silenced using systemic RNA interference (RNAi). The results indicated that silence of Dicer-1 reduced the expression of miRNAs, and resulted in a high mortality of A. gossypii when fed on both tannic acid and gossypol. The silencing of Argonaute-1 resulted in the mortality of A. gossypii by the treatment of tannic acid significantly increased compared with control, however, the sensitivity of A. gossypii to gossypol was not significantly changed. It suggested that miRNAs play potential regulatory roles in the response of A. gossypii to plant allelochemicals. These results should be useful to understand the molecular mechanisms of the cotton aphid adaption to plant allelochemicals.

One-step hydrothermal synthesis of photoluminescent carbon nanodots with selective antibacterial activity against Porphyromonas gingivalis.

Carbon dots (CDs) with high quantum yield (QY), low toxicity and good biocompatibility are the major quests of biomedical research. In this paper, we develop a green, simple hydrothermal approach to synthesize water-soluble, nontoxic, highly photoluminescent carbon nanodots (CNDs) from Metronidazole, which possess selective antibacterial activity against obligate anaerobes for the first time. Metronidazole was used as a sole precursor to prepare CNDs at 250 °C (CNDs-250) for 8 h. After the CNDs-250 with an average size of 2.9 nm, consisting of a highly carbon crystalline core and various surface groups were obtained, the formation and fluorescence mechanisms of CNDs were further explored by adjusting the reaction time and reaction temperatures, respectively. Biological experimental data proved that CNDs-250 can only inhibit the growth of obligate anaerobes, such as Porphyromonas gingivalis (P. gingivalis) directly, instead of further functionalization. Besides, CNDs-250 with a QY around 28.1% exhibit an obvious excitation-dependent emission, which will be conducive to multicolor bioimaging. And it may not only develop a new approach for researchers to prepare multifunctional CDs, but also provide a valuable strategy for the theranostics of some diseases as well as other fields.

A novel 3-D photoluminescent cuprous chloride polymer based on bifunctional imidazolate/tetrazolate bridges.

A novel 3-D cuprous chloride polymer [CuCl(µ5-L)]n (1, HL = 1-tetrazole-4-imidazole-benzene) has been hydrothermally synthesized and structurally characterized. 1 displays a 3-D network with a bimodal fsc-3,5-Cmce-2 topological type constructed by the linkages of rare [CuCl]+ cations and L- ligands. The photoluminescence properties and density functional theory calculations of 1 have also been studied.

A series of new lanthanide fumarates displaying three types of 3-D frameworks.

A series of lanthanide fumarates [Sm2(fum)3(H2fum)(H2O)2] (1, H2fum = fumaric acid), [Ln2(fum)3-(H2O)4]·3H2O {Ln = Tb (2a), Dy (2b)} and [Ln2(fum)3(H2O)4] {Ln = Y (3a), Ho (3b), Er (3c), Tm (3d)} were prepared by the hydrothermal method and their structures were classified into three types. The 3-D framework of compound 1 contains a 1-D infinite [Sm-O-Sm]n chain built up from the connection of SmO8(H2O) polyhedra sharing edges via three -COO group bridges of fumarate ligands, which is further constructed into a 3-D network structure with three kinds of fumarate ligands. Compounds 2a-b are isostructural and consist of a 3-D porous framework with 0-D cavities for the accommodation of chair-like hexameric (H2O)6 clusters. Compounds 3a-d are isostructural and have a 3-D network structure remarkably different from those of 1 and 2a-b, due to the different coordination numbers for the Ln(3+) ions and distinct fumarate ligand bridging patterns. A systematic investigation of seven lanthanide fumarates and five reported compounds revealed that the well-known lanthanide contraction has a significant influence on the formation of lanthanide fumarates. The magnetic properties of compounds 1, 2b and 3b-3d were also investigated.