RESUMO
Hirshfeld surfaces and two-dimensional fingerprint plots are used to analyse the intermolecular interactions in two new phosphorothioic triamide structures, namely N,N',N''-tris(3,4-dimethylphenyl)phosphorothioic triamide acetonitrile hemisolvate, P(S)[NHC6H3-3,4-(CH3)2]3·0.5CH3CN or C24H30N3PS·0.5CH3CN, (I), and N,N',N''-tris(4-methylphenyl)phosphorothioic triamide-3-methylpiperidinium chloride (1/1), P(S)[NHC6H4(4-CH3)]3·[3-CH3-C5H9NH2](+)·Cl(-) or C21H24N3PS·C6H14N(+)·Cl(-), (II). The asymmetric unit of (I) consists of two independent phosphorothioic triamide molecules and one acetonitrile solvent molecule, whereas for (II), the asymmetric unit is composed of three components (molecule, cation and anion). In the structure of (I), the different components are organized into a six-molecule aggregate through N-H···S and N-H···N hydrogen bonds. The components of (II) are aggregated into a two-dimensional array through N-H···S and N-H···Cl hydrogen bonds. Moreover, interesting features of packing arise in this structure due to the presence of a double hydrogen-bond acceptor (the S atom of the phosphorothioic triamide molecule) and of a double hydrogen-bond donor (the N-H unit of the cation). For both (I) and (II), the full fingerprint plot of each component is asymmetric as a consequence of the presence of three fragments. These analyses reveal that H···H interactions [67.7 and 64.3% for the two symmetry-independent phosphorothioic triamide molecules of (I), 30.7% for the acetonitrile solvent of (I), 63.8% in the phosphorothioic triamide molecule of (II) and 62.9% in the 3-methylpiperidinium cation of (II)] outnumber the other contacts for all the components in both structures, except for the chloride anion of (II), which only receives the Cl···H contact. The phosphorothioic triamide molecules of both structures include unsaturated C atoms, thus presenting C···H/H···C interactions: 17.6 and 21% for the two symmetry-independent phosphorothioic triamide molecules in (I), and 22.7% for the phosphorothioic triamide molecule of (II). Furthermore, the N-H···S hydrogen bonds in both (I) and (II), and the N-H...Cl hydrogen bonds in (II), are the most prominent interactions, appearing as large red spots on the Hirshfeld surface maps. The N···H/H···N contacts in structure (I) are considerable, whereas for (II), they give a negligible contribution to the total interactions in the system.
RESUMO
A single crystal of U3Fe2Ge7 was synthesized by the tin-flux method, and its structural and electronic properties were studied. The compound crystallizes in the orthorhombic crystal structure of La3Co2Sn7 type with two Wyckoff sites for the U atoms. U3Fe2Ge7 displays a ferromagnetic order below TC = 62 K. Magnetization measurements in static (up to 14 T) and pulsed (up to 60 T) magnetic fields revealed a strong two-ion uniaxial magnetic anisotropy. The easy magnetization direction is along the c axis and the spontaneous magnetic moment is 3.3 µB per formula unit at 2 K. The moment per Fe atom is 0.2 µB, as follows from Mössbauer spectroscopy. The magnetic moments are oriented perpendicular to the shortest inter-uranium distances that occur within the zigzag chains in the ab plane, contrary to other U-based isostructural compounds. The magnetization along the a axis reveals a first-order magnetization process that allows for a quantitative description of the magnetic anisotropy in spite of its enormous energetic strength. The strong anisotropy is reflected in the specific heat and electrical resistivity that are affected by a gap in magnon spectrum.
