-This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater, i. e. , 1, 2, 4, 5-tetrahydroxybenzen -O, O' , O', O'''- tetraaceti...-This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater, i. e. , 1, 2, 4, 5-tetrahydroxybenzen -O, O' , O', O'''- tetraacetic acid (TTAH4). The synthetic method of TTAH4, its enrichment behaviour for potassium ion in low concentration solution and seawater, and the chemical structure of its corresponding potassium salt have been investigated. A mechanism which caused the uptake of potassium ion is suggested. Elementary analysis and IR-spectrum determination of the potassium salt proved correct evidence for a polynuclear complex, i. e. , (TTAH3K)n. Thus, the mechanism which caused the uptake of potassium ion may be interpreted in terms of the formation of polynuclear chains as a continual sandwich type coordination complex.展开更多
A reaction between steroidal sapogenins and hydrogen sulfide promoted by BF3•Et2O is described.The thio-diosgenin and thiotigogenin comprising a sulfur atom on the F ring can be easily afforded in one step under this ...A reaction between steroidal sapogenins and hydrogen sulfide promoted by BF3•Et2O is described.The thio-diosgenin and thiotigogenin comprising a sulfur atom on the F ring can be easily afforded in one step under this mild reaction condition.Furthermore,a hypothetical mechanism is also shown.展开更多
文摘-This paper first presents a new potassium reagent and efficient enrichment agent for direct recovery of potassium from seawater, i. e. , 1, 2, 4, 5-tetrahydroxybenzen -O, O' , O', O'''- tetraacetic acid (TTAH4). The synthetic method of TTAH4, its enrichment behaviour for potassium ion in low concentration solution and seawater, and the chemical structure of its corresponding potassium salt have been investigated. A mechanism which caused the uptake of potassium ion is suggested. Elementary analysis and IR-spectrum determination of the potassium salt proved correct evidence for a polynuclear complex, i. e. , (TTAH3K)n. Thus, the mechanism which caused the uptake of potassium ion may be interpreted in terms of the formation of polynuclear chains as a continual sandwich type coordination complex.
基金support from the Natural Science Foundation of China(Nos.29070070,29372077).
文摘A reaction between steroidal sapogenins and hydrogen sulfide promoted by BF3•Et2O is described.The thio-diosgenin and thiotigogenin comprising a sulfur atom on the F ring can be easily afforded in one step under this mild reaction condition.Furthermore,a hypothetical mechanism is also shown.
