Bispidine Platform Grants Full Control over Magnetic State of Ferrous Chelates in Water

International audienceA bicyclic ligand platform for iron(II), which allows total control over the complex’s magnetic properties in aqueous solution simply by varying one of the six coordination sites of the bispidine ligand, is reported. To achieve this, an efficient synthetic route to an N5 bispidine framework (ligand L4) that features an unsubstituted N-7 site is established. Then, by choosing appropriate N-7-coordinating substituents, the spin state of choice can be imposed on the corresponding ferrous complexes under environmentally relevant conditions in water and near-room temperature. Importantly, the first low-spin and diamagnetic iron(II) chelates in the bispidine series, both in the solid state and in aqueous solution, are reported. The eradication of head-on steric clashes between pendent coordinating arms is at the origin of this success. A new pair of constitutionally similar ferrous coordination compounds of a multidentate ligand system is obtained, which exhibits a distinctly binary (off–on) magnetic relationship. The new synthetic intermediate L4 may be substituted in just one step by any desired pendent arm, thus allowing access to complexes with finely tuned magnetic properties

Furfuryl­ammonium chloridozincophosphate

In the title compound, [ZnCl(HPO4)](C5H8NO), polymeric inorganic layers constructed from ZnO3Cl and PO4 tetra­hedra are linked by O atoms: O—H⋯O hydrogen bonds occur within the layers. The organic cations occupy the interlayer regions and interact with the layers by way of N—H⋯O, N—H⋯Cl, and C—H⋯Cl hydrogen bonds

Deprotonative metalation of five-membered aromatic heterocycles using mixed lithium-zinc species

International audienceDeprotonation of benzoxazole, benzothiazole, benzo[b]thiophene, benzo[b]furan, N-Boc protected indole and pyrrole, and N-phenylpyrazole using an in situ mixture of ZnCl2*TMEDA (0.5 equiv) and lithium 2,2,6,6-tetramethylpiperidide (1.5 equiv) in THF at room temperature was described. The reaction was evidenced by trapping with iodine, regioselectively giving the expected functionalized derivatives in 52 to 73% yields. A mixture of mono- and disubstituted derivatives was obtained starting from thiazole. Cross-coupling reactions of 2-metalated benzo[b]thiophene and benzo[b]furan with heteroaromatic chlorides proved possible under palladium catalysis. A reaction pathway where the lithium amide and zinc diamide present in solution behave synergically was proposed for the deprotonation reaction, taking account of NMR and DFT studies carried out on the basic mixture

Bis(2-amino-1,3-benzothia­zol-3-ium) tetra­chloridozincate(II)

The asymmetric unit of the title compound, (C7H7N2S)2[ZnCl4], contains a network of 2-amino­benzothia­zolium cations and tetra­hedral [ZnCl4]2− anions. The crystal packing is influenced by cation-to-anion N—H⋯Cl and C—H⋯Cl hydrogen bonds. The [ZnCl4]2− anions have a distorded tetra­hedral geometry. Inter­molecular π–π stacking inter­actions are present between neighboring benzene rings, thia­zole and benzene rings and neighboring thia­zole rings [centroid–centroid distances = 3.711 (2), 3.554 (1), 3.536 (2) and 3.572 (1) Å]

Bis(1-benzyl­piperazine-1,4-diium) hexa­chloridocadmate(II) dihydrate

The asymmetric unit of the title compound, (C11H18N2)2[CdCl6]·2H2O, consists of one 1-benzyl­piperazine-1,4-diium dication, one water mol­ecule and one-half of a [CdCl6]4− anion, located on an inversion centre. The crystal packing is governed by an extensive three-dimensional network of inter­molecular O—H⋯Cl, C—H⋯Cl, N—H⋯O and N—H⋯Cl hydrogen bonds, two of them bifurcated

4-(3-Ammonio­prop­yl)morpholin-4-ium tetra­chloridozincate(II)

In the title compound, (C7H18N2O)[ZnCl4], the ZnII ion is coordinated by four Cl atoms in a close to tetra­hedral geometry. The crystal packing exhibits C—H⋯Cl, N—H⋯Cl and N—H⋯O hydrogen bonds

trans-Diaqua­bis­(dl-valinato-κ2 N,O)nickel(II)

In the title complex, [Ni(C5H9NO2)2(H2O)2], the NiII atom, located on a centre of inversion, is trans-coordinated by two O atoms and two N atoms from d-bidentate valine and l-bidentate valine ligands and two water O atoms in an octa­hedral geometry. In the crystal, the discrete mononuclear units are linked into a three-dimensional network via O—H⋯O and N—H⋯O hydrogen bonds. C—H⋯O inter­actions are also observed

1-Benzyl­piperazine-1,4-diium bis­(perchlorate) monohydrate

In the title compound, C11H18N2 2+·2ClO4 −·H2O, one perchlor­ate anion is disordered over two orientations in a 0.66 (3):0.34 (3) ratio. Inter­molecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds link the cations, anions and water mol­ecules into ribbons extending along [100]

Bis(2-amino-5-chloro­pyridinium) tetra­chloridozincate

The asymmetric unit of the title compound, (C5H6ClN2)2[ZnCl4], contains two 2-amino-5-chloro­pyridinium cations and one [ZnCl4]2− dianion which are held together by N—H⋯Cl and C—H⋯Cl hydrogen bonds. The [ZnCl4]2− anions have a distorted tetra­hedral geometry. Weak inter­molecular π–π stacking inter­actions exist between neighbouring aromatic rings of the cations with a centroid–centroid distance of 3.712 (7) Å

1-(4-Chloro­phen­yl)piperazine-1,4-diium tetra­chlorido­zincate(II) monohydrate

In the crystal structure of the title compound, (C10H15ClN2)[ZnCl4]·H2O, the Zn atom is coordinated by four Cl atoms in a tetrahedral geometry. The water mol­ecules and the 1-(4-chloro­phen­yl)piperazine-1,4-diium cations inter­act with the [ZnCl4]2− anions through O—H⋯Cl, N—H⋯Cl, N—H⋯O and C—H⋯Cl hydrogen bonds (five simple and one bifurcated). Inter­molecular π–π stacking inter­actions are present between adjacent aromatic rings of 1-(4-chloro­phenyl)­piperazine-1,4-diium cations (the centroid–centroid distance is 3.453 Å)