RESUMO
One pseudopentasupertetrahedral chalcogenidometalate cluster, [(BuSn)3SnCd4S13(OH)]·6(H+DMP) (PPS-1; H+DMP = protonated 3,5-dimethylpiperidine), has been isolated by use of an organotin precursor. They are arranged to generate two types of tetrahedrally patterned cages, which further interconnect to form a diamond network. Owing to the covalent attachment of abundant alkyl groups, PPS-1 exhibits excellent hydrophobicity and could be used as an assembly substance for building liquid marbles.
RESUMO
Coordination polymers (CPs) based on metal-sulfur bonds are rare; we herein realize a series of thiol-functionalized linker-based CPs (thiol-CPs), MTBT (M = Fe, Co and Zn; TBT = dehydrated 4,4'-thiobisbenzenethiol), which feature an anionic two-dimensional (2D) network, [M(TBT)2]n2n-, with the tetrahedral coordination unit {MS4} serving as a node. These compounds exhibit excellent hydrolytic stability, especially in alkaline solution (20M NaOH for five days), which is the highest value reported for CPs so far. In addition, among them, CoTBT displays favorable photo-thermal conversion effectiveness under an energy power of 0.5 W cm-2 808 nm laser irradiation for 15 s, with the temperature rising rapidly from room temperature to 135.2 °C.
RESUMO
Four isomorphic P2 chalcogenide clusters named [Sn11In9Cu6S44]·11(H+DBU) (1) (DBU = 1,8-diazabicyclo[5.4.0] undec-7-ene), [Sn10In10Cu6Se44]·6(H22+DMAPA)·2(DMAPA)·9EG (2) (DMAPA = 3-dimethylaminopropylamine, EG = ethylene glycol), [Sn10In10Cu6S40O4]·6[H22+PMDETA]·10EG (3) (PMDETA = pentamethyldiethylenetriamine), [Sn10Ga10Cu6S40O4]·6(H22+DMAPA)·7EG (4) have been isolated via organotin precursor and mixed-metal strategy. These clusters exhibit excellent solubility in organic solvents. The continuous-regulation of optical band and optical limiting performance have been realized through precise controlled substituting engineering of cationic and anionic elements.
RESUMO
Nanosized mesoporous γ-alumina (M-γ-Al2O3) was first prepared and then modified into a carbon paste to fabricate a novel modified carbon paste electrode. The prepared alumina has pores with an amorphous wall and large surface area. The electrochemical behavior of the modified carbon paste electrode was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The modified carbon paste electrode was employed to determine Pb2+ and Cd2+ simultaneously by a differential pulse voltammetry (DPV) method. Amperometric determination was carried out in 0.1 mol L-1 NaAc-HAc buffer solution (pH 6.0) after enriching for 360 s at -1.0 V. The oxidation peak currents of Pb2+ and Cd2+ were proportional to their concentration in the range of 0.001-10 µmol L-1 and 0.01-10 µmol L-1, respectively. The detection limits of Pb2+ and Cd2+ were 0.20 nmol L-1 and 2.0 nmol L-1 (S/N = 3), respectively. The modified carbon paste electrode shows good stability, repeatability and sensitivity. The proposed method was applied to the determination of Pb2+ and Cd2+ in water samples with satisfactory results.
RESUMO
The interfacial electron transfer of glucose oxidase (GOx) on a poly(glutamic acid)-modified glassy carbon electrode (PGA/GCE) was investigated. The redox peaks measured for GOx and flavin adenine dinucleotide (FAD) are similar, and the anodic peak of GOx does not increase in the presence of glucose in a mediator-free solution. These indicate that the electroactivity of GOx is not the direct electron transfer (DET) between GOx and PGA/GCE and that the observed electroactivity of GOx is ascribed to free FAD that is released from GOx. However, efficient electron transfer occurred if an appropriate mediator was placed in solution, suggesting that GOx is active. The PGA/GCE-based biosensor showed wide linear response in the range of 0.5-5.5 mM with a low detection limit of 0.12 mM and high sensitivity and selectivity for measuring glucose.