catena-Poly[[lead(II)-bis­(μ2-quinolin-8-ol­ato)-κ3 N,O:O;κ3 O:N,O] N,N-di­methyl­formamide hemisolvate]

The asymmetric unit of the title compound, {[Pb(C9H6NO)2]·0.5C3H7NO}n, comprises Pb(quinolate)2 and half a dimethyl­formamide mol­ecule (which is disordered about a centre of inversion). The quinolate ligands N,O-chelate to a PbII ion and simultaneously bridge a neighbouring PbII ion to form a polymeric chain along [100] comprising Pb-linked Pb2O2 distorted rhombi. These chains pack to form a square grid, with the channels thus defined occupied by the disordered solvent mol­ecules

Poly[(μ4-3-carb­oxy­benzoato-κ5 O 1:O 1,O 1′:O 1′:O 3)(quinolin-8-olato-κ2 N,O)lead(II)]

The asymmetric unit of the title complex, [Pb(C8H5O4)(C9H6NO)]n, comprises a PbII cation, a quinolin-8-olate anion and a 3-carb­oxy­benzoate anion. The coordination geometry of the PbII atom is defined by one N and six O atoms, as well as a stereochemically active lone pair of electrons, and is based on a Ψ-dodeca­hedron. The quinolin-8-olate is chelating and the 3-carb­oxy­benzoate anion forms bonds to four different PbII atoms. The benzoate end of the 3-carb­oxy­benzoate ligand chelates one PbII atom and simultaneously bridges two PbII atoms on either side, forming a chain along the b axis. The carboxyl end of the 3-carb­oxy­benzoate connects to a neighbouring chain by employing its carbonyl atom to form a bond to a PbII atom and the hydroxyl group to form a hydrogen bond to a quinolin-8-olate O atom. Thereby, a layer is formed in the bc plane

{2,2′-[o-Phenyl­enebis(nitrilo­methanylyl­idene)]diphenolato-κ4 O,N,N′,O′}nickel(II) monohydrate

The NiII atom in the title monohydrate, [Ni(C20H14N2O2)]·H2O, is coordinated within a cis-N2O2 square-planar donor set provided by the tetra­dentate Schiff base ligand. Overall, the mol­ecule has a curved shape with the dihedral angle formed between the planes of the outer benzene rings being 13.92 (18)°. The water mol­ecule was found to be disordered over two positions [ratio 0.80 (1):0.20 (1)] and the major component is linked to the complex via an O—H⋯O hydrogen bond

{5,5′-Dimeth­oxy-2,2′-[1,1′-(2,2-dimethyl­propane-1,3-diyldinitrilo)­diethyl­idyne]diphenolato-κ4 O,N,N′,O′}copper(II) monohydrate

The tetra­dentate dianion in the title complex hydrate, [Cu(C23H28N2O4)]·H2O, provides the CuII atom with a cis-N2O2 donor set. There is a significant twist from a regular square-planar geometry with the dihedral angle formed between the two six-membered CuOC3N chelate rings being 32.14 (8)°. The water mol­ecule forms hydrogen bonds to each of the coordinating O atoms of a given complex mol­ecule. Supra­molecular layers in the bc plane are formed in the crystal packing through C—H⋯O and C—H⋯π inter­actions

2-{(1E)-1-[(3-{(E)-[1-(2-Hy­droxy-4-meth­oxy­phen­yl)ethyl­idene]amino}-2,2-di­methyl­prop­yl)imino]­eth­yl}-5-meth­oxy­phenol

Mol­ecules of the title compound, C23H30N2O4, are located on a crystallographic mirror plane. The mol­ecule has a curved shape with the dihedral angle formed between the two benzene rings being 55.26 (5)°. Intra­molecular O—H⋯N hydrogen bonds are noted. In the crystal, supra­molecular layers are formed in the ac plane owing to the presence of C—H⋯π inter­actions

{4,4′-Dibromo-2,2′-[2,2-dimethyl­propane-1,3-diylbis(nitrilo­methanylyl­idene)]diphenolato-κ4 O,N,N′,O′}nickel(II)

In the title compound, [Ni(C19H18Br2N2O2)], the NiII ion, lying on a twofold rotation axis, is coordinated by two N atoms and two O atoms from the Schiff base ligand in a distorted square-planar geometry. Weak inter­molecular C—H⋯O hydrogen bonds stabilize the crystal structure

Bis(μ-azido-κ2 N 1:N 1)bis­{(acetato-κ2 O,O′)[2,4,6-tris­(2-pyrid­yl)-1,3,5-triazine-κ3 N 2,N 1,N 6]lead(II)}

The complete dinuclear title complex, [Pb2(C2H3O2)2(N3)2(C18H12N6)2], is generated by the application of a crystallographic centre of inversion. The PbII atom is coordinated by three N atoms of the tridentate ligand, two O atoms derived from an asymmetrically coordinating acetate ligand, and two azido-N atoms derived from two asymmetrically bridging azido ligands. The metal coordination geometry can be described as a square anti-prism with one position occupied by an unseen lone pair of electrons. In the ligand, the two coordinating pyridine rings are almost co-planar with the central pyrazine ring [dihedral angles = 0.47 (17) and 0.83 (18)°], but the terminal ring is twisted [dihedral angle = 19.76 (18)°]. In the crystal, the presence of π–π inter­actions [ring centroid distance between pyridyl rings = 3.581 (2) Å] leads to supra­molecular chains along the a-axis direction

Diiodido(1,10-phenanthroline-5,6-dione-κ2 N,N′)mercury(II)

The HgII atom in the title complex, [HgI2(C12H6N2O2)], is tetra­hedrally coordinated by the N atoms of the chelating 1,10-phenanthroline-5,6-dione ligand and two I atoms. The range of tetra­hedral angles is broad, viz. 68.94 (17)° for the chelate angle to a wide 132.627 (15)° for the I—Hg—I angle. The ligand mol­ecule is non-planar with the O atoms lying 0.422 (5) and −0.325 (5) Å out of the plane through the remaining atoms [r.m.s. deviation = 0.068 Å]. Mol­ecules are consolidated in the crystal packing by C—H⋯O inter­actions

Purinergic signalling and immune cells

This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

Di-μ-azido-κ4N:N-bis({2-[(3-amino-2,2-dimethylpropyl)iminomethyl]-6-methoxyphenolato-1κ3N,N′,O1}copper(II))

The complete molecule of the title complex, [Cu2(C13H19N2O2)2(N3)2], is generated by the application of a centre of inversion. The central Cu2N2 core is a rhombus as the μ2-azide ligands bridge in an asymmetric fashion. Each CuII atom is also coordinated by a monoanionic tridentate Schiff base ligand via the anticipated oxide O, imine N and amine N atoms. The resulting N4O coordination geometry is based on a square pyramid. No specific intermolecular interactions are noted in the crystal packing, but the amine H atoms form intramolecular N—H...O(oxide)/N(azide) hydrogen bonds