Neptunium(V) Isothiocyanate Complexes with 4'-Aryl-Substituted 2,2':6',2″-Terpyridines and N,N-Dimethylacetamide as Molecular Ligands

Np(V) azide complexes with electroneutral N-donor ligands

Two new Np(V) azide complexes with electroneutral N-donor ligands of terpyridine derivatives have been synthesized and structurally characterized: [(NpO2)(Cl-Terpy)(N3)(H2O)] (1) and a centrosymmetric dimer [(NpO2)(EtO-Terpy)(N3)]2·2CH3OH (2). The coordination polyhedra of Np atoms in compounds are pentagonal bipyramids with “yl” oxygen atoms in apical positions. The equatorial plane of the bipyramid in complex 1 is formed by: a nitrogen atom from an anion, three nitrogen atoms from an electroneutral Cl-Terpy ligand and an oxygen atom of a water molecule. The equatorial plane of bipyramids in dimer 2 is formed by five nitrogen atoms: two atoms from two anions [N3]− and three atoms from EtO-Terpy. In compound 1, the anion [N3]− acts as a monodentate ligand, and in compound 2, the anion [N3]− is a bidentate-bridging ligand.

Np(V) dicyanamide complexes with electroneutral N-donor ligands

Three new complexes of Np(V) dicyanamide with electroneutral N-donor ligands have been synthesized and structurally characterized: two with terpyridine derivatives: [(NpO2)(Cl-Terpy)(DMA)(N(CN)2)]·0.5DMA (1), [(NpO2)(TPTZ)(N(CN)2)(H2O)]·2H2O·CH3OH (2) and a dimeric complex with bipyridine [(NpO2)(Bipy)(N(CN)2)(H2O)]2·2(CH3OH) (3). In compounds 1–3, the coordination polyhedra of Np atoms are pentagonal bipyramids with “yl” oxygen atoms in apical positions. The equatorial plane of the bipyramids is formed by nitrogen atoms of the anions [N(CN)2]− and N-donor electroneutral ligands (Cl-Terpy, TPTZ, Bipy) and the oxygen atom of water molecule (1, 3) or DMA (2). In compounds 1 and 2, the [N(CN)2]− anions manifest themselves as monodentate ligands, and in compound 3 dicyanamide is a bidentate-bridging ligand.