STRUCTURE OF PARAMAGNETIC DIFURAZANOPYRAZINE AMMONIUM SALTS

• Published in: Journal of structural chemistry Vol. 63; no. 11; pp. 1779 - 1786
• Main Authors: Ovcharenko, V. I., Bogomyakov, A. S., Fokin, S. V., Romanenko, G. V., Strizhenko, K. V., Sheremetev, A. B., Egorov, M. P.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.11.2022; Springer Nature B.V
• Subjects: Ammonia; Atomic; Atomic/Molecular Structure and Spectra; Chemical bonds; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Molecular; Optical and Plasma Physics; Oxidation; Physical Chemistry; Solid State Physics; pyrazine; ammonium; stable radical; magnetic properties; structure
• ISSN: 0022-4766; 1573-8779
• DOI: 10.1134/S0022476622110075

The structure of previously unknown compounds NH 4 (HL • )(HL)·3H 2 O and NH 4 (L • ) x (HL) 1 x ·H 2 O (L • is a radical anion, HL is a deprotonated difurazanopyrazine derivative, HL • is a product of difurazanopyrazine oxidation) prepared by the oxidation of difurazanopyrazine (H 2 L) in aqueous ammonia is described. It is established that the shortest distances between the neighboring {L} in NH 4 (HL • )(HL)·3H 2 O and NH 4 (L • ) x (HL) 1 –x ·H 2 O fall within a fairly narrow range of 3.15-3.30 Å, despite the fact that they have substantially different stackings of {L} fragments. The bond lengths and bond angles of molecules {L} in all the studied compounds differ insignificantly. The energy of interaction between the paramagnetic centers in ammonium difurazanopyrazine salts is sharply diminished due to the decreased content of paramagnetic particles and, consequently, increased distances between these particles.