Phosphoramides bearing isoxazole derivative: spectroscopic and structural characterization, study of hydrogen-bonding interactions and two lanthanide complexes (LnIII = Ce and Eu)

Hirshfeld surface analysis of two new phosphorothioic triamide structures

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.