ABSTRACT
The different hydrogen bond interactions in two organic-inorganic hybrid manganese halide compounds, namely [A]2[MnBr4] (A = N-butyl-N-methylpyrrolidinium ([P14]+) for (1) and N-butyl-N-methylpiperidinium ([PP14]+) for (2)), lead to distinct photoluminescence quantum yields (81% for 1; 55% for 2). Further applications of luminescent 1 are also developed.
ABSTRACT
A series of hybrid tellurium chlorides based on ionic liquids (ILs), namely, α-[Bmim]2TeCl6 (1, Bmim = 1-butyl-3-methyl imidazolium), ß-[Bmim]2TeCl6 (2), [HOOCMim]2TeCl6 (3, HOOCMim = 1-carboxymethyl-3-methyl imidazolium), [Bzmim]2TeCl6 (4, Bzmim = 1-benzyl-3-methyl imidazolium), [EPy]2TeCl6 (5, EPy = 1-ethylpyridinium), [Bmmim]2TeCl6 (6, Bmmim = 1-butyl-2,3-dimethyl imidazolium), have been synthesized and characterized. Different kinds of supramolecular networks have been obtained via self-assemblies of isolated [TeCl6]2- anions and various ionic liquid cations. Interestingly, all the title compounds exhibit semiconducting behaviors: their optical absorption edges calculated from reflectance spectra are in the range of 2.54-2.68 eV; their electrical conductivities measured by using two-probe direct current (DC) method indicate values from 2.06 × 10-9 to 4.65 × 10-6 S/cm, which are typical for semiconductors and comparable to the reported crystalline hybrid metal halides. The luminescent property studies reveal that only compounds 3 and 6 exhibit intense emissions both at 77 and 298 K, probably owing to the minimum distortion of the TeCl6 octahedra in 3 and 6.
ABSTRACT
Trace elements in pearls have characteristic disciplines and functions. The previous work had paid attention to different characteristics of trace elements in freshwater and seawater cultured pearls, but only limited species of trace elements have been detected by former testing techniques and analysis methods, and the test results have not been further analyzed. With the advantages of detection in good capability and high speed, inductively coupled plasma mass spectrometer (ICP-MS) can concurrently test various trace and ultra-trace elements. In the present paper, trace elements of cultured pearls in freshwater and seawater were measured by ICP-MS, and analyzed compared by a method of data processing. The results show that: (1) The kinds of higher content of trace elements (Sr, Zn, Ni, Ba, Mn, Cr, Cu, Pb, Ti, Co, Ce, Zr, La, Rb) in cultured pearls are approximately the same, but the total amount of trace elements in freshwater cultured pearls is significantly less than that of seawater cultured pearls. (2) The content of trace elements (Sr, Mn, Ba, Ni, Cr, Pb) in freshwater cultured pearls is more regular, and has a relatively fixed sequence from high to low, namely Sr > Mn > Ba > Ni > Cr > Pb. The content of trace elements in seawater cultured pearls is quite different. Sr is enriched in all samples. There is no a stable order of contents for the other trace elements. (3) There is a significant correlation among some trace elements in cultured pearls. The conclusion is instructive to indicate cultured environment, cultured technology, identification, comprehensive development and utilization of cultured pearls.
