Copper(II) Halide Salts with 1-(4′-Pyridyl)-Pyridinediium

The compounds [1,4′-bipyridine]-1,1′-diium [CuCl4] (1) and [1,4′-bipyridine]-1,1′-diium [CuBr4] (2) were prepared and their crystal structures and magnetic properties are reported. The compounds are isomorphous and crystallize in the monoclinic space group C2/c. The cation crystallizes in a two-fold disordered fashion with the terminal nitrogen and carbon atoms exhibiting 50% occupancies. This results in a crystal packing arrangement with significant hydrogen bonding that is very similar to that observed in the corresponding 4,4′-bipyridinediium complexes. Temperature dependent magnetic susceptibility measurements and room temperature EPR spectroscopy indicate the presence of very weak antiferromagnetic exchange. The data were fit to the Curie–Weiss law and yielded Weiss constants of −0.26(5) K (1) and −1.0(1) K (2).

(−)-Sparteinium tetrachloridozincate monohydrate

The title ionic compound, (C15H28N2)[ZnCl4]·H2O, is isostructural with the CuIIanalogue published previously [Leeet al.(2004).Bull. Korean Chem. Soc.25, 823–828; Jasiewiczet al.(2006).J. Mol. Struct.794, 311–319]. The [ZnCl4]2−anion is, however, much more close to the tetrahedral conformation than the [CuCl4]2−ion. In the tetrachloridozincate anion, the Cl—Zn—Cl angles are in the range 103.57 (3)–116.81 (3)°.

1-(2,3-Di-methyl-phen-yl)piperazine-1,4-diium tetra-chlorido-cuprate(II)

In the title salt, (C12H20N2)[CuCl4], the Cu(II) atom occupies a general position in a flattened tetra-hedral environment by Cl ligands, characterized by Cl-Cu-Cl angles of 134.04 (3) and 137.18 (4)°. The six-membered piperazinediium ring adopts a chair conformation. The organic cation and inorganic anion inter-act through N-H⋯Cl and C-H⋯Cl hydrogen bonds, forming a three-dimensional network.

Bis(3-methyl-pyridinium) tetra-(chlorido/bromido)cuprate(II)

The structure of the title salt, (C₆H₈N)₂[CuCl_3.4Br_0.6], consists of two 3-methyl­pyridinium cations and a distorted tetra­hedral [CuCl_3.4Br_0.6]²⁻ dianion. Substitutional disorder with Br is exhibited for three of the Cl atoms of the anion, giving a mixed chloride/bromide cuprate(II) anion. In the crystal, inter­molecular N—H⋯Cl hydrogen bonds link two cations to one anion, forming a three-ion aggregate. These are connected into a supra­molecular chain along the b axis via π–π inter­actions between the pyridinium rings [centroid–centroid distance = 3.743 (3) Å].

Indolizidine and quinolizidine alkaloids

This review covers the isolation, structure determination, synthesis, chemical transformations and biological activity of indolizidine and quinolizidine alkaloids. Included in the review are the hydroxylated indolizidines lentiginosine, swainsonine, castanospermine and their analogues; alkaloids from animal sources, including ants, amphibians and beetles; indolizidine alkaloids from the genera Polygonatum, Prosopis and Elaeocarpus; indolizidine and phenanthroindolizidine alkaloids; alkylquinolizidine alkaloids, including myrtine, epimyrtine, plumerinine and Lycopodium metabolites; Lythraceae and Nuphar alkaloids; lupine alkaloids; and alkaloids from marine sources. 150 references are cited.