Reinvestigation of Np2Se5: A Clear Divergence from Th2S5 and Th2Se5 in Chalcogen–Chalcogen and Metal–Chalcogen Interactions

Autor:	Geng Bang Jin, Yung-Jin Hu, S. Skanthakumar, James A. Ibers, Lynda Soderholm, Richard G. Haire, Brian J. Bellott
Rok vydání:	2013
Předmět:	Chemistry Transition temperature Atmospheric temperature range Magnetic susceptibility XANES Inorganic Chemistry Metal Crystallography Chalcogen Paramagnetism Tetragonal crystal system visual_art visual_art.visual_art_medium Physical and Theoretical Chemistry
Zdroj:	Inorganic Chemistry. 52:9111-9118
ISSN:	1520-510X 0020-1669
Popis:	Single crystals of Np2Se5 have been prepared through the reactions of Np and Se at 1223 K in an Sb2Se3 flux. The structure of Np2Se5, which has been characterized by single-crystal X-ray diffraction methods, crystallizes in the tetragonal space group P42/nmc. The crystallographic unit cell includes one unique Np and two Se positions. Se(1) atoms form one-dimensional infinite chains along the a and b axes with alternating intermediate Se-Se distances of 2.6489 (8) and 2.7999 (8) Å, whereas Se(2) is a discrete Se(2-) anion. Each Np is coordinated to 10 Se atoms and every NpSe10 polyhedron shares faces, edges, or vertices with 14 other identical metal polyhedra to form a complex three-dimensional structure. Np LIII-edge X-ray Absorption Near Edge Structure (XANES) measurements show a clear shift in edge position to higher energies for Np2Se5 compared to Np3Se5 (Np(3+)2Np(4+)Se(2-)5). Magnetic susceptibility measurements indicate that Np2Se5 undergoes a ferromagnetic-type ordering below 18(1) K. Above the transition temperature, Np2Se5 behaves as a paramagnet with an effective moment of 1.98(5) μB/Np, given by a best fit of susceptibilities to a modified Curie-Weiss law over the temperature range 50-320 K.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fc1ef4a8bef22cbcd3e87fe7e7f0f039 https://doi.org/10.1021/ic401384t Zobrazit plný text záznamu