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A series of isostructural compounds Na(HL)(CHCOO)Ln(Al(OH)MoO)(HO)·10HO [L = nicotinate; Ln = Eu (1), Tb (2)] and Na(HL)(CHCOO)EuTbLa(AlMo(OH)O)(HO)·10HO (3-8, L = nicotinate), wherein Anderson-type polyanions AlMo(OH)O as basic inorganic building blocks are connected by Eu(CHCOO)(HL)(HO)] and [Na(HO)] cations, resulting in formation of three-dimensional lanthanide metal-organic open frameworks, were synthesized successfully with AlCl·6HO, NaMoO·2HO, nicotinic acid, and lanthanide nitrates as starting materials. The compounds were characterized by UV-vis, IR, elemental analysis, powder XRD, and TG-DTA measurements. The single-crystal structures of compounds 1 and 2 show that the two compounds display three-dimensional open frameworks with 1D channels along the b and c axes. Investigation of the energy transfer mechanism indicated that the organic nicotinate ligand can transfer energy efficiently to Tb rather than Eu. The influence of the POM moiety on the fluorescence of the compounds is also studied. Compounds 1-8 exhibit tunable luminescence color, and emitting of white light was realized through adjusting the molar ratio of Eu:Tb:La within the compounds.

Three new isostructural chiral silver-lanthanide heterometal-organic frameworks [AgLn(μ-OH)(bpdc)(NO)(HO)](NO)·2HO [Ln = Eu (1), Tb (2, Sm (3); Hbpdc = 2,2'-bipyridine-3,3'-dicarboxylic acid] based on heptanuclear lanthanide clusters [Ln(μ-OH)] comprised of one-dimensional triple right-handed helical chains were hydrothermally synthesized. Various means such as UV-vis spectroscopy, IR spectroscopy, elemental analysis, powder X-ray diffraction, and thermogravimetric/differential thermal analysis were used to characterize the compounds, wherein compound 3 was crystallographically characterized. In the structure of compound 3, eight μ-OH groups link seven Sm ions, forming a heptanuclear cluster, [Sm(μ-OH)], and the adjacent [Sm(μ-OH)] clusters are linked by the carboxylic groups of bpdc ligands, leading to the formation of a one-dimensional triple right-handed helical chain. The adjacent triple right-handed helical chains are further joined together by coordinating the pyridyl N atoms of the bpdc ligands with Ag, resulting in a chiral three-dimensional silver(I)-lanthanide(III) heterometal-organic framework with one-dimensional channels wherein NO anions and crystal lattice HO molecules are trapped. The compounds were studied systematically with respect to their photoluminescence properties and energy-transfer mechanism, and it was found that Hbpdc (the energy level for the triplet states of the ligand Hbpdc is 21505 cm) can sensitize Eu luminescence more effectively than Tb and Sm luminescence because of effective energy transfer from bpdc to Eu under excitation in compound 1.

In recent years, whitefly-transmitted begomovirues (family Geminiviridae) have caused severe leaf curl disease on tobacco and tomato in southern China, but have not been found on pepper. In August 2009, pepper plants (Capsicum frutescens) grown in the field in Panzhihua City of Sichuan Province (southwestern China), from where the occurrence of begomoviruses has not been reported previously, showed stunting, leaf yellowing, and mild curling symptoms. To identify possible begomoviruses, total DNA was extracted from three infected pepper plants (SC117, SC118, and SC119) with typical symptoms. Using degenerate primer pair PA/PB specific for members of the genus Begomovirus (2), a 500-bp DNA fragment covering parts of the intergenic region and V2 gene of the genome of begomoviruses was amplified from all samples. No amplification was observed from healthy plant extracts. The PCR product from SC118 was cloned and two clones were chosen to be sequenced. Alignment of the partial DNA sequences revealed that the cloned products from isolate SC118 were nearly identical (98.5%) and most closely related to Tobacco curly shoot virus isolate Y35 (TbCSV-[China:Yunnan 35:2001]; Accession No. AJ420318) (96.9 and 97.3% identity, respectively). Therefore, the entire genome of isolate SC118 was sequenced. Overlap primers TbCSV-F(5′-CCGCCGTCTCAACTTCGACAG-3′) and TbCSV-R(5′-ATCTGCTGGTCGCTTCGACAT-3′) were designed to amplify the full-length genome of SC118. The complete genome sequence of SC118 was determined to be 2,746 nucleotides (Accession No. GU001879) long, with two open reading frames (ORFs) in the virion-sense strand and four ORFs in the complementary-sense strand, typical of the Old World begomoviruses. A comparison with other reported sequences of begomoviruses shows that the genome of SC118 shares the highest nucleotide sequence identity (99.7%) with TbCSV-[China:Yunnan 35:2001]. When PCR was used to detect TbCSV from the other two isolates (SC117 and SC119) with TbCSV specific primer pair Y35F1 and Y35+10R (4), which amplified the fragment covering the whole C2 and C3 genes and the partial C1 and V1 genes of the genome of TbCSV, an amplicon of approximately 1.0 kb was obtained from all samples. To determine whether a satellite molecule was associated with the three virus isolates, a universal betasatellite abutting primer pair (beta01 and beta02) was used (1). No amplification product was detected. In previous studies, it was demonstrated that only 11 isolates were associated with betasatellites among 39 TbCSV-infected, field-collected samples (3), and betasatellites could be associated with noncognate begomoviruses (4). Therefore, the three isolates examined in this study are too few to come to a conclusion that betasatellites are not associated with TbCSV infection of pepper plants. A detailed search for the presence of betasatellites needs to be conducted to draw a definitive conclusion. The above results confirmed that samples SC117, SC118, and SC119 were infected by TbCSV. To our knowledge, this is the first report of TbCSV on pepper in China. References: (1) R. W. Briddon et al. Mol. Biotechnol. 20:317, 2002. (2) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (3) Z. Li et al. Phytopathology 95:902, 2005. (4) L. Qing et al. Phytopathology 99:716, 2009.