ABSTRACT
Reactions of [Et4N][Tp*WS3(CuCl)3] (1) (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate) with 2 equiv. of AgOTf (OTf- = trifluoromethanesulfonate) and 1 equiv. of several bidentate pyridine ligands including 2,5-bis(pyridine-4-yl)thiazolo[5,4-d]thiazole (L1), 2,7-di(pyridin-4-yl)-9H-fluorene (L2), 2,7-di(pyridin-4-yl)-9H-carbazole (L3), and 2,7-di(pyridin-4-yl)-9H-fluoren-9-one (L4) afforded four W/Cu/S cluster-based supramolecular compounds [(Tp*WS3Cu2Cl)2(L1)] (2), {[(Tp*WS3Cu3)2(µ-Cl)2(µ4-Cl)]2(L2)2}(OTf)2 (3), {[(Tp*WS3Cu3)2(µ-Cl)2(µ4-Cl)]2(L3)2}(OTf)2 (4) and {[(Tp*WS3Cu3)2(µ-Cl)2(µ4-Cl)]2(L4)2}(OTf)2 (5). Compounds 2-5 were characterized by elemental analysis, IR, UV-vis, 1H NMR, and single-crystal X-ray diffraction analysis. The neutral cluster 2 behaves as a supramolecular wire constructed by L1 bridging two butterfly-shaped [Tp*WS3Cu2Cl] cores. The cluster cations of 3-5 contain two [(Tp*WS3Cu3)2(µ-Cl)2(µ4-Cl)]+ cores linked by two L2, L3, or L4 ligands, which finally formed a cationic supramolecular rectangle. The third-order nonlinear-optical (NLO) properties of 3-5 in DMF were also investigated by Z-scan techniques and their NLO responses were enhanced compared to those of their precursor 1.
ABSTRACT
Solvothermal reactions of AgNO3 with N1,N4-bis(5-fluoropyridin-3-yl)succinamide (bfps) in MeCN afforded the one-dimensional cationic coordination polymer {[Ag(bfps)]NO3}n (1). Upon treatment of 1 with the anionic azo dye orange II (NaOII) in aqueous solution, the NO3- anions of 1 could be gradually exchanged by the OII- anions via an anion-exchange process. The resulting OII anion-exchanged products {[Ag(bfps)](NO3)0.85(OII)0.15}n (2) and {[Ag(bfps)](NO3)0.1(OII)0.9}n (3) were formed by different molar ratios of 1 and the newly formed phase "{[Ag(bfps)](OII)}n" (4), confirmed by PXRD patterns. Relative to those of the precursors 1 and NaOII, complexes 2 and 3 demonstrated enlarged photocurrent responses and reduced dielectric constants and dielectric losses, which could be correlated with the OII- contents in their structures. Complex 3 acquired a stable anodic photocurrent of 12.06 µA, which was 4.9 times higher than that of 1. The dielectric constant (εr = 4.2) and dielectric loss (0.002) of 3 were nearly frequency independent in the range from 1 to 106 Hz. The results provide an interesting insight into the rational assembly of CP-dye complexes and their tunable optoelectronic applications.
ABSTRACT
OBJECTIVE: To establish the validation method and criteria for counting bacteria and fungi in microbial limit test which is described in the Pharmacopeia of China (ChP) 2005. METHOD: According to the method set up for validation, the tested microorganisms with known counts were added to samples followed by the determination of the recovery. RESULT: With different preparing method for testing samples, the recoveries for the tested microorganisms in testing samples were found to be over 70%. CONCLUSION: Validation method for counting contaminated bacteria and fungi in drugs is recommended to follow the method established in this paper. The recovery for tested microorganisms should be not less than 70%.
