Intracomplex π-stacking interactions between three adjacent molecules of phosphoryl-containing 1,8-naphthyridine (L) in lanthanide(III) complexes [LnL3]3+: Crystal structures, DFT calculations, and solution study by electrospray ionization mass spectrometry (ESI-MS)

Crystal structures of the dioxane hemisolvates of N-(7-bromo-methyl-1,8-naphthyridin-2-yl)acetamide and bis-[N-(7-di-bromo-methyl-1,8-naphthyridin-2-yl)acetamide]

The syntheses and crystal structures of N-(7-bromo-methyl-1,8-naphthyridin-2-yl)acetamide dioxane hemisolvate, C11H10BrN3O·0.5C4H8O2, (I), and bis-[N-(7-di-bromo-methyl-1,8-naphthyridin-2-yl)acetamide] dioxane hemisolvate, 2C11H9Br2N3O·0.5C4H8O2, (II), are described. The mol-ecules adopt a conformation with the N-H hydrogen pointing towards the lone electron pair of the adjacent naphthyridine N atom. The crystals of (I) are stabilized by a three-dimensional supra-molecular network comprising N-H⋯N, C-H⋯N and C-H⋯O hydrogen bonds, as well as C-Br⋯π halogen bonds. The crystals of compound (II) are stabilized by a three-dimensional supra-molecular network comprising N-H⋯N, C-H⋯N and C-H⋯O hydrogen bonds, as well as C-H⋯π contacts and C-Br⋯π halogen bonds. The structure of the substituent attached in the 7-position of the naphthyridine skeleton has a fundamental influence on the pattern of inter-molecular noncovalent bonding. While the Br atom of (I) participates in weak C-Br⋯Oguest and C-Br⋯π contacts, the Br atoms of compound (II) are involved in host-host inter-actions via C-Br⋯O=C, C-Br⋯N and C-Br⋯π bonding.

Crystal structure of N-(7-di-bromo-methyl-5-methyl-1,8-naphthyridin-2-yl)benzamide-pyrrolidine-2,5-dione (1/1)

The title compound, C17H13Br2N3O·C4H5NO2, is a co-crystal of N-(7-di-bromo-methyl-5-methyl-1,8-naphthyridin-2-yl)benzamide and pyrrolidine-2,5-dione (succinimide). The benzamide mol-ecule exhibits pseudo-mirror symmetry, with an r.m.s. deviation of the non-H atoms of 0.09 Å (except for the two Br atoms). The angle between the least-squares planes of the two mol-ecules is 26.2 (2)°. In the crystal, the two mol-ecules are mutually linked by N-H⋯O and N-H⋯N hydrogen bonds. The packing is consolidated by C-H⋯(O,N) hydrogen bonds and π-π stacking inter-actions.

Extraction and coordination studies of a carbonyl–phosphine oxide scorpionate ligand with uranyl and lanthanide(iii) nitrates: structural, spectroscopic and DFT characterization of the complexes

A scorpionate organophosphorus ligand exhibits promising extraction properties and variable denticity in f-block element complexes in the solid state and solution.