The title salt, C 9 H 15 N 4 O 3 + ·Br − [systematic name: 5-[(2 S )-2-(3-azaniumylpropanamido)-2-carboxylatoethyl]-1 H -imidazol-3-ium bromide], contains four cations and four anions in the asymmetric unit. The dipeptide is a 'cationic zwitterion' with two localized positive charges and one delocalized negative charge. Two of the cations adopt an anti conformation for the non-hydrogen atoms of the –C(=O)—CH 2 —CH 2 —NH 3 + grouping and two adopt a gauche conformation. In the extended structure, numerous N—H...O, N—H...(O,O) and N—H...Br hydrogen bonds link the components into (010) sheets and the structure is consolidated by weak C—H...O and C—H...Br interactions.

In the title compound, (C4H11N2)[NaBr2(H2O)3], the complete organic cation, which adopts a typical chair conformation, is generated by crystallographic inversion symmetry and one of the N-bonded H atoms is half occupied. The sodium ion (site symmetry m) at the centre of the complex anion adopts a distorted trigonal–bipyramidal coordination geometry with the water molecules in the equatorial sites and the bromide ions in the axial sites. In the extended structure, O—H...Br hydrogen bonds generate a porous ‘honeycomb' three-dimensional network of complex anions encapsulating [010] channels occupied by the cations, which are linked to each other by N—H...N hydrogen bonds and anchored to the honeycomb network via N—H...Br hydrogen bonds.

Three potential hosts with an amine-conjugated nitro group, derived from reacting 4,5-difluoro-1,2-dinitrobenzene or 1,3-difluoro-4,6-dinitrobenzene with different amines, have been crystallised and their structures solved by X-ray single crystal structure determinations. The first of these gives a complex structure in space group P 3 1 with Z ’ = 12 owing to different conformations of the butyl side chains. ‘Doughnut’ like hydrogen-bonded six rings occur in the extended structure with F . . . F separations across the rings of about 13 Å, but there is no overall porosity because the doughnuts are staggered with respect to the c -direction of the trigonal unit cell. The other two potential hosts did not form porous networks.

The crystal structures of two hydro-chloride salts of pyridoxal-N-acyl-hydrazone-Q (Q = heterocyclic aromatic ring) derivatives, viz. (E)-3-hy-droxy-5-(hy-droxy-meth-yl)-2-methyl-4-{[(pyridin-4-ylformamido)-imino]-meth-yl}pyridin-1-ium chloride dihydrate, C14H15N4O3 +·Cl-·2H2O, (I), and (E)-3-hy-droxy-5-(hy-droxy-meth-yl)-2-methyl-4-{[(pyrimidin-2-ylformamido)-imino]-meth-yl}pyridin-1-ium chloride dihydrate, C13H14N5O3 +·Cl-·2H2O, (II) are described. The cations, which are protonated at the pyridine N atom of the pyridoxal ring, have similar overall conformations: the dihedral angles between the pyridoxal ring and the terminal aromatic ring are 12.63 (12) and 6.11 (15)° for (I) and (II), respectively. Each cation features an intra-molecular O-H⋯N hydrogen bond, which closes an S(6) ring, but a difference arises in the conformation of the C-C-C-O fragment terminated by the the ring carbon atom bonded to the side chain and the O atom of the hy-droxy-methyl group: gauche for (I) and anti for (II). The extended structures of (I) and (II) feature numerous strong (N-H and O-H donors) and weak (C-H donor) hydrogen bonds. In (I), the NHp (pyridine) grouping links to the terminal N atom of the pendant unprotonated pyridine ring of an adjacent cation to generate [010] chains, whereas the NHh (hydrazide) and OHhm (hy-droxy-meth-yl) moieties link to chloride ion acceptors. In (II), the NHp and OHhm groupings bond to chloride anions whereas NHh bonds to a water mol-ecule. Hydrogen-bonded chains of water mol-ecules occur in (I) and centrosymmetric tetra-mers in (II). The Hirshfeld surfaces of (I) and (II) are computed and the structures of related compounds are briefly compared.

A new hydrazone-hydrazide, methyl3-(pyridine-2yl-methylene)hydrazinecarboxylate(3-pymc, C8H9N2O2)and its mixed ligand copper(II) complex of formula [(Cu(3,5-dnb)2(3-pymc)2(H2O)2] (3,5-dnb = 3,5-dinitrobenzoate, C7H3N2O6 -) were prepared and characterized using elemental analysis, UV-vis and FT-IR spectroscopy. A single crystal X-ray study revealed that pairs of N-monodentate 3-pymc ligands, O-monodentate 3,5-dnb anions and H2O molecules occupy the coordination sites of a centrosymmetric Jahn-Teller distorted octahedron about the Cu2+ ion. The thermal decomposition properties of the complex were studied by simultaneous TG-DTA measurements. Copper oxide was prepared by the thermal decomposition of the copper complex at 700 degrees Cin air for 2 hrs: the formed CuO was studied by PXRD, SEM and TEM analyses.

N,N-Ditosyl-2-aminodiphenylamine was prepared by the tosylation of 2-aminodiphenylamine with tosylchloride in dichloromethane. Unwanted isomers owing to the tosylation of the diarylamine were not formed. This compound was fully characterized by IR, UV/Vis, NMR, m/z, and mp, including an X-Ray single crystal structure determination. It was fragmented in an Atmospheric Solids Analysis Probe (ASAP) mass spectrometer showing a series of fragments down to phenazine.

A mixed ligand ZnCl 2 complex of N -tolyl- p -phenylenediamine, ZnCl 2 (C 13 H 14 N 2 ) 2 , was unexpectedly formed in situ in the Zn/EtOH/H + reduction of 4-nitrophenylaminotoluene and was characterised by an X-ray single crystal structure determination. The Zn 2+ cations were presumably formed by oxidation with the cHCl in EtOH used to clean the zinc metal surface. Two failed mauveine syntheses with preformed building blocks suggest that linear trimers are mauveine precursors in the William Henry Perkin 1856 mauveine synthesis. An unusual synthesis of phenyliminoquinone (C 13 H 13 N 3 O 2 ) is reported which provides further evidence on the mechanism of mauveine formation.

Based on the chemotherapeutic success of cisplatin, carboplatin and oxaliplatin as anticancer drugs, and silver sulfadiazine (AgSDZ) as an antibacterial drug, exploration of the anticancer and antibacterial potential of new metal complexes has received increasing attention during the last three decades. Saccharin (sacH) is a well-known worldwide artificial sweetener. Its deprotonated form (sac) is a polyfunctional ligand, coordinating to different metals due to the presence of hard and soft donor sites (see comment below). In the last two decades, a large number of mixed-ligand metal complexes containing sac and tsac ligands have been synthesized and in some cases, they have demonstrated better in vitro and in vivo biological activities than approved standard drugs. This review describes the design, anticancer and antimicrobial activity screening of metal complexes of sac and its thio derivative (tsac) as prospective drug candidates. The metal sac complexes herein are categorized according to the ancillary ligands present in the complexes, and their anticancer and antimicrobial activities are discussed in detail. The main molecular targets and cellular pathways involved in the mechanism of action of the metal complexes were also explored. The growing field demonstrates promising in vitro and in vivo results with a significant interest for future research in medicinal inorganic chemistry.

The ethanol–water layered syntheses and crystal structures of the coordination polymers [Cd(C17H22N2)2(H2O)2]·2(ClO4)·C17H22N2·C2H5OH 2 and [Cd(C17H22N2)2(NO3)2] 3 are reported, where C17H22N2 is a flexible spacer, 1,7-bis(4-pyridyl)heptane. In compound 2, trans-CdO2N4 octahedral nodes are linked by pairs of bridging ligands to result in [001] looped polymeric chains. The chains stack in the [100] direction to form (010) pseudo layers. Sandwiched between them are secondary sheets of free ligands, perchlorate ions and ethanol solvent molecules. Hydrogen bonds between these species help to consolidate the structure. Compound 3 contains trans-CdO2N4 octahedral nodes as parts of regular 44 nets, which propagate in the (103) plane. Three independent nets are interpenetrated.

A new hydrazone–hydrazide, ethyl 2-[1-(thiophen-2-yl)ethylidene]hydrazine-1-carboxylate) (2-aeh, C9H12N2O2S) and its polymeric silver complex of formula [Ag(2-aeh)(NO3)]n, catena-[(μ-nitrato)-(ethyl 2-[1-(thiophen-2-yl)ethylidene]hydrazine-1-carboxylate)-silver(I)], are reported. A single crystal X-ray study of the complex revealed a tridentate S, N, O-coordination mode for the ligand, with the bridging nitrate anions generating an infinite chain of AgSO5N nodes. Silver nanoparticles (Ag NPs) of diameter ∼24 nm were synthesized using the silver complex as a single-source solid state molecular precursor. The nanoparticles were analyzed using PXRD, SEM, EDX and HR-TEM. The supercapacitor properties of 2-aeh, the silver complex and Ag NPs were also studied using cyclic voltammetry. An evaluation of antioxidant activity demonstrated that the silver complex shows good scavenging efficiency against ABTS•+, DPPH•, O2•–, NO• and OH− radicals. The band gap of the AgNPs is 2.73 eV and they catalyze the degradation of methylene blue by KOH under sun light.

The crystal structures of the title compounds, which arose from the same reaction, consist of discrete complexes in which the cobalt cations are either in a CoN2O3 trigonal–bipyramidal or a CoN2O4 octa­hedral coordination.

The title compound, C8H11PS, which melts below room temperature, was crystallized at low temperature. The P—S bond length is 1.9623 (5) Å and the major contributors to the Hirshfeld surface are H⋯H, S⋯H/H⋯S and C⋯H/H⋯C contacts.

Microorganisms are a valuable source of pharmaceutically active chemicals, serving as scaffolds for synthesis as well as lead structures. Investigating novel biomes frequently yields intriguing chemistry; the Atacama Desert in Chile is one such example. This study reports the isolation of a new reduced anthracycline-related compound from the Atacama Desert-derived bacterium Saccharothrix S26. Structural characterisation was achieved by one-dimensional and two-dimensional NMR, HR-LCMS, and X-ray crystallography. The compound was tested against the ESKAPE pathogens, bovine mastitis-related pathogens, and the fungal strain Cryptococcus neoformans, but no antimicrobial activity was observed.

The absolute configuration and stability of two thianthrene chiral sulfoxides has been determined by means of X-ray single-crystal structure determinations. The analyses and configurations allow verification that the diastereomeric sulfoxides are stable in solution and are not interconverting, which has been suggested in some studies of sulfoxides. The two thianthrene sulfoxides have slightly different Rf values, which allowed their separation using flash chromatography on silica. The spots run back-to-back, which posed a challenge for their separation. The pure, separated compounds in solution remain as separate, single spots on a Thin Layer Chromatography (TLC) plate.

2,4-Difluoronitrobenzene has been reacted with a linker diamine (ethylenediamine or propylenediamine) and butylamine, in either order, to give new molecular building blocks for porous supramolecular networks. Two structures were established by X-ray single crystal structure determinations. The propylenediamine structure displays small pores, which may be due to the longer and more flexible linker in the structure.

In the crystal structure of the title compound, Ni(NCS)2(C6H7N)2 (C6H7N = 4-methyl­pyridine), the NiII cations are in an octa­hedral coordination and are linked by pairs of anionic ligands into corrugated chains in which the cations show alternating all-trans and cis–cis–trans coordination geometries. Upon heating, the title compound transforms into Ni(NCS)2(C6H7N), which is isotypic to its Cd analog as proven by a Rietveld refinement.

In the title compound, {(C6H8N)[Zn2(HPO3)2(H2PO3)]}n, the constituent ZnO4, HPO3 and H2PO3 polyhedra of the inorganic component are linked into (010) sheets by Zn—O—P bonds (mean angle = 134.4°) and the layers are reinforced by O—H...O hydrogen bonds. The protonated templates are anchored to the inorganic sheets via bifurcated N—H...(O,O) hydrogen bonds.

In the structure of the title co-crystal, C3H3N3O2·C5H8N2, the components are linked by a set of directional O—H⋯N, N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds to yield a two-dimensional mono-periodic arrangement. The structure propagates in the third dimension by extensive π–π stacking inter­actions of nearly parallel mol­ecules of the two components, following an alternating sequence. The primary structure-defining inter­action is very strong oxime-OH donor to pyrazole-N acceptor hydrogen bond [O⋯N = 2.587 (2) Å], while the significance of weaker hydrogen bonds and π–π stacking inter­actions is comparable.

Different supramolecular motifs are formed by the crystallisation of amino-substituted derivatives of quinoxaline, pyrimidine and pyridazine. These were made from the corresponding mono- or dichlorinated heterocycles by a nucleophilic displacement reaction. The pyridine-type nitrogen atoms activate the chlorine atoms because they can stabilise a negative charge, which forms when the amine attacks the ring. One amino group can be attached under mild conditions in hot ethanol or acetonitrile, but the first then deactivates the ring so the second requires more forceful conditions using a pressure vessel at 150 °C. Butylamine is frequently used because it reduces the polarity of the product, making it easier to purify and isolate. The extended structure of the quinoxaline derivatives 16–18 show a common ‘pincer’ hydrogen-bond motif, with a quinoxaline nitrogen atom accepting two N–H···N hydrogen bonds, giving a spiral or helical axis. The chain symmetries are 41, 21 and 31, respectively, depending on the substituents. A stereoview of each is shown. The pyrimidine derivatives 19, 12, 20, 14 and 21 form hydrogen-bonded tapes and compound 20 forms inversion dimers.

The CoII-catalysed synthesis and crystal structure is reported for the title compound, which features a symmetric N⋯H+⋯N unit.