Dihydropyrazines reacted with 1,2-diamines to form tetraazadecalins as intermediates, and then the reaction proceeded forward to dissociate into alternate dihydropyrazine and diamine, or backward to dissociate into the starting materials in certain equilibrium. The product distribution is controlled by diamine-exchange equilibrium reaction. The various equilibrium reactions were analyzed by NMR spectroscopy.
Experimental and theoretical evidence suggests carbamate intermediates play a key role in CO2 sequestration catalysed by sterically hindered amines
作者:Phil Jackson
DOI:10.1007/s11224-014-0431-5
日期:2014.10
comparable to the MEA value (45 kJ mol−1), whereas the primaryamines with tertiary alpha carbons have slightly larger values (60–70 kJ mol−1). The organicamine values are much lower than the value for ammonia (93 kJ mol−1). The results indicate CO2 chemisorption proceeds via a carbamate intermediate for all aqueous primary and secondaryamines. Hindered carbamates are susceptible to further chemical
Rapid and sensitive LC-MS approach to quantify non-radioactive transition metal impurities in metal radionuclides
作者:Dexing Zeng、Carolyn J. Anderson
DOI:10.1039/c3cc39071c
日期:——
A rapid and sensitive LC-MS approach for the quantification of non-radioactive metal contaminants present in metal radionuclide formulations was developed. Traditional 12C/1H and heavy stable isotope 13C/2H-labeled chelator–amino acid conjugates are used as chelating agents to quantify contaminating transition metals, allowing for determination of effective specific activity of radio-metals.