Synthesis and Investigation of 2,6-Bis(picrylamino)-3,5-dinitro-pyridine (PYX) and Its Salts

Thomas M Klapötke; Jörg Stierstorfer; Michael Weyrauther; Tomasz G Witkowski

doi:10.1002/chem.201600769

Synthesis and Investigation of 2,6-Bis(picrylamino)-3,5-dinitro-pyridine (PYX) and Its Salts

Chemistry. 2016 Jun 13;22(25):8619-26. doi: 10.1002/chem.201600769. Epub 2016 May 4.

Authors

Thomas M Klapötke¹, Jörg Stierstorfer², Michael Weyrauther², Tomasz G Witkowski²

Affiliations

¹ Department of Chemistry, Ludwig-Maximilian University, Butenandtstraße 5-13, 81377, Munich, Germany. tmk@cup.uni-muenchen.de.
² Department of Chemistry, Ludwig-Maximilian University, Butenandtstraße 5-13, 81377, Munich, Germany.

PMID: 27144716
DOI: 10.1002/chem.201600769

Abstract

2,6-Bis(picrylamino)pyridine (1; pre-PYX) and 2,6-bis(picrylamino)-3,5-dinitropyridine (2; PYX) were synthesized using an improved literature method. Compounds 1 and 2 were reinvestigated in detail and the X-ray structures (1: ρ=1.698 g cm(-3) at 173 K; 2: ρ=1.757 g cm(-3) at 298 K) are given. The reactions of 2 with different bases, such as alkali metal hydroxides (sodium, potassium, rubidium, cesium), and N-bases (ammonia, hydrazine, hydroxylamine, guanidinium carbonate, aminoguanidine bicarbonate) are reported, as well as metathesis reactions producing energetic salts. Several energetic compounds were synthesized and characterized for the first time using vibrational (IR, Raman) and multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, and DSC. The crystal structures of four energetic salts were determined using low temperature single-crystal X-ray diffraction. Heats of formation for the metal-free species were calculated using the Gaussian 09 software. Detonation parameters were estimated using the EXPLO5 program. The sensitivities towards impact, friction, and electrostatic discharge were also determined.

Keywords: energetic materials; pyridine; salts; structure elucidation; thermally stable explosive.