RESUMEN

Chemical attribution signatures (CAS) are being investigated for the sourcing of chemical warfare (CW) agents and their starting materials that may be implicated in chemical attacks or CW proliferation. The work reported here demonstrates for the first time trace impurities from the synthesis of tris(2-chloroethyl)amine (HN3) that point to the reagent and the specific reagent stocks used in the synthesis of this CW agent. Thirty batches of HN3 were synthesized using different combinations of commercial stocks of triethanolamine (TEA), thionyl chloride, chloroform, and acetone. The HN3 batches and reagent stocks were then analyzed for impurities by gas chromatography/mass spectrometry. All the reagent stocks had impurity profiles that differentiated them from one another. This was demonstrated by building classification models with partial least-squares discriminant analysis (PLSDA) and obtaining average stock classification errors of 2.4, 2.8, 2.8, and 11% by cross-validation for chloroform (7 stocks), thionyl chloride (3 stocks), acetone (7 stocks), and TEA (3 stocks), respectively, and 0% for a validation set of chloroform samples. In addition, some reagent impurities indicative of reagent type were found in the HN3 batches that were originally present in the reagent stocks and presumably not altered during synthesis. More intriguing, impurities in HN3 batches that were apparently produced by side reactions of impurities unique to specific TEA and chloroform stocks, and thus indicative of their use, were observed.

Asunto(s)

Sustancias para la Guerra Química/química , Cromatografía de Gases y Espectrometría de Masas , Compuestos Orgánicos/análisis , Acetona/análisis , Acetona/química , Aminas/análisis , Aminas/química , Sustancias para la Guerra Química/síntesis química , Análisis Discriminante , Etanolaminas/análisis , Etanolaminas/química , Análisis de los Mínimos Cuadrados , Compuestos Orgánicos/química , Óxidos de Azufre/análisis , Óxidos de Azufre/química

RESUMEN

Macromolecules with built-in redox gradients are of much interest due to their potential in a variety of optoelectronic and energy-harvesting applications. In this paper, the design and synthesis of nonconjugated dendrons with redox gradients to guide the charge flow from the core to the periphery is described. The dendrons reported here are based on benzyl ether connectivities. The repeat units of the dendrons are based on triarylamines, and the periphery units of the dendrons are based on N,N,N',N'-tetraarylbenzidine units. The presence of a redox gradient after incorporation of these charge-transporting units into the dendrons is supported by cyclic voltammetric studies.