ABSTRACT
The hydrothermal reaction of Co(II)/Cu(II), 5-hydroxyisophthalic acid and dipyridophenazine leads to the generation of two 3D chiral coordination polymers, [M(hip)(DPPZ)](n) (M = Co(), Cu(), H(2)hip = 5-hydroxyisophthalic acid, DPPZ = dipyridophenazine), which contain M-hip-M helical chains (M = Co, Cu) and possess a new four-connected 6(6) topological net. The resulting crystals were not a racemic mixture but an enantiomeric excess, which was confirmed by the measurement of optical rotation of the bulk samples using solid state vibrational circular dichroism (VCD) and solid circular dichroism (CD) based on the large crystals from one crystallization. The magnetic properties of 1 and 2 have been investigated by variable-temperature magnetic susceptibility and magnetization measurements, and the results reveal that antiferromagnetic interactions exist in 1 and 2.
ABSTRACT
To search for a new method of determining, we developed a new flow injection analyzer, applied to the atomic absorption spectrophotometer, relying on it without flame in place of visible spectrophotometer, and studied the appropriate condition for the determination of aluminum in sediments, thus built up a kind of new analytical test technique. Three peak and two valley absorption values (A1, A2, A3, A4 and A5) can be continuously obtained simultaneously that all can be used for quantitative analysis, then we discussed its theory and experiment technique. Based on the additivity of absorbance (A = A1+A2+A3+A4+ A5), the sensitivity of FIA is enhanced, and its precision and linear relation are also good, raising the efficiency of AAS. The simple method has been applied to determining Al in sediments, and the results are satisfactory.
