Chiral Thianthrenes.

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.

New Functionalized Phenoxazines and Phenothiazines.

The reaction of either 2-aminophenol or 2-(N-methylamino)phenol with 1,2-difluoro-4,5-dinitrobenzene and sodium carbonate in EtOH gives 2,3-dinitrophenoxazines. One nitro group, conjugated to the aryl ether, was displaced from 2,3-dinitro-10-methylphenoxazine with different nucleophiles: BuNH2, KOEt, and KOH. The reaction of 2-aminothiophenol with 1,2-difluoro-4,5-dinitrobenzene under the same conditions gives 2,3-dinitrophenothiazine. This reacted with BuNH2 forming 2-butylamino-3-nitrophenothiazine. The dihedral angles of the different compounds are compared.

Porous and Close Packed Supramolecular Assemblies from 2,4-Difluoronitrobenzene with Three Different Linkers and an n-Butylamine Cap.

A porous structure formed from sheets with cavities and two close packed structures were crystallised from building blocks prepared from 2,4-difluoronitrobenzene, a diamine linker and n-butylamine. The porous structure crystallised from a flexible building block prepared using 1,4-diaminobutane as linker. The close packed structures were prepared using either piperazine or 1,4-bis(aminomethyl)benzene as a linker and have less conformational freedom.

Heterocyclic Synthesis of Crowded Aposafranones: Structure of 1-Methyl-8-dimethylamino-10-phenylphenazin-2-(10H)one and Related Compounds.

Oxidative condensation of three p-phenylenediamines with 3-hydroxy-2-methyl-N-(phenylamino)benzene gives new coloured aposafranones. 2-Methylresorcinol is easy to convert into the asymmetric building block 3-hydroxy-2-methyl-N-(phenylamino)benzene with aniline. The aposafranones are sterically crowded because of the 1-methyl and N-phenyl groups. The UV/Vis absorption maxima are in the range 530-545 nm.

Potential Building Blocks for 1,4-Dihydro-N-heteroacenes.

Studies have been performed aimed at the synthesis of N-heteroacenes via substitution reactions of 4,5-difluoro-1,2-dinitrobenzene with a diamine. The fluorine atoms are displaced first, followed by an activated nitro group. Two intermediates have been characterised by X-ray single-crystal structure determinations. Their intermolecular interactions were examined by Hirshfeld surfaces to assess their suitability for organic molecular electronics. The high reactivity of the phenazine, which is prone to oxidise and rearrange, as are displacement products prepared from it, is explained by the formation of a cis-aci-nitro form from the secondary amine of the phenazine and a nitro group.

A Potential Iterative Approach to 1,4-Dihydro-N-Heteroacene Arrays.

A new method for the synthesis of substituted 1,4-dihydrophenazines is reported and the structure of N-butyl-5-methyl-3-nitro-5,10-dihydrophenazine is proven by an X-ray single-crystal structure determination.

Crystalline Forms of Trazodone Dihydrates.

In this study, treatment of anhydrous trazodone powder with ammonium carbamate in warm water crystallised two new polymorphs or dihydrates of trazodone after 5 h, whose structures were determined by X-ray single crystal diffraction. Each dihydrate contains infinite zigzag hydrogen-bonded chains of water molecules, which are stabilised by the N4 acceptor atom of the piperazine ring and the pendant carbonyl O1 atom of the triazole ring, as well as other water molecules. The strong dipole moment expected for the O1 atom makes it a good hydrogen bond acceptor for stabilising the chains of water molecules. Each molecule of trazodone has a similar conformation in both hydrates, except for the propyl chains, which adopt different conformations: anti-gauche in the ß hydrate (triazole N-C-C-C and C-C-C-piperazine N) and anti-anti in the γ hydrate. Both piperazine rings adopt chair conformations, and the exocyclic N-C bonds are in equatorial orientations. The Hirshfeld surfaces and two-dimensional fingerprint plots for the polymorphs were calculated using CrystalExplorer17, which indicated contacts significantly shorter than the sum of the van der Waals radii in the vicinity of the piperazine N4 and triazole O1 atoms corresponding to the strong hydrogen bonds accepted by these atoms.

Photochemical Fragmentation of Irgacure PAG 103.

Photoisomerization of Irgacure PAG 103 followed by photocyclization and fragmentation leads to three tricyclic thieno[2,3-b]quinoline-4-carbonitrile heterocyclic compounds. The release of acid which can catalyze polymer resist modifications is indicated by the low pH of an aqueous extract. These reactions are discussed in view of possible mechanisms and how these might influence future design strategies.

Synthesis and Magnetic Properties of a Copper Cube: [Cu4(OH)4(C16H18N2)4]4+ (ClO4)4 C3H6O [C16H18N2=(E)-1,6-[Di(pyridin-4-yl)hex-3-ene].

The synthesis of a Cu4(OH)4 cube which is coordinated by four molecules of the dipyridyl ligand 1,6-[di(pyridin-4-yl)hex-3-ene] is reported. This compound has a trans double bond which restricts the conformational freedom of the ligand and favours coordination within a unique copper cube. The structure was solved by an X-Ray single crystal structure determination and low temperature magnetic susceptibility measurements examined its magnetic properties. The cube classification corresponds to the type I classification of Mergehenn and Haase and the short/long distribution of Cu ⋅⋅⋅ Cu separations in the cube as defined by Ruiz. The magnetic susceptibility measurements show paramagnetic behaviour down to 50 K but below this the copper cube shows weak ferromagnetic exchange interactions. The low temperature magnetic susceptibility characteristics are examined in detail then modelled and compared to other similar Cu4O4 copper cubes.

An Organic Zeolite With 10†ŠDiameter Pores Assembles From a Soluble and Flexible Building Block by Non-Covalent Interactions.

Two similar molecular building blocks, which both contain a hydrogen-bonded nitro group, have been prepared and crystallised. One structure has more flexibility with a butyl side chain which allows an open framework organic zeolite to form with large 10 Šdiameter pores, whereas the other structure has less flexibility with an aryl side chain and is close packed. The pore size is comparable with those of the aluminophosphate VPI-5 (12 Å). It is concluded that some flexibility in the design of the building block for porous organic molecular materials was beneficial.

An unexpected oxidation: NaK5Cl2(S2O6)2 revisited.

The title compound, NaK5Cl2(S2O6)2 [systematic name: sodium penta-potassium dichloride bis-(di-thio-nate)], arose as an unexpected product from an organic synthesis that used di-thio-nite (S2O42-) ions as a reducing agent to destroy excess permanganate ions. Compared to the previous study [Stanley (1953 ▸). Acta Cryst.6, 187-196], the present tetra-gonal structure exhibits a root 2a × root 2a × c super-cell due to subtle changes in the orientations of the di-thio-nate anions. The structure can be visualized as a three-dimensional framework of [001] columns of alternating trans-NaO4Cl2 and KO4Cl2 octa-hedra cross-linked by the di-thio-nate ions with the inter-stices occupied by KO6Cl2 polyhedra to generate a densely packed three-dimensional framework. The asymmetric unit comprises two sodium ions (site symmetries 4 and -4, four potassium ions (site symmetries = -4, 4, 1 and 1), three chloride ions (site symmetries = 4, 4 and 2) and two half-di-thio-nate ions (all atoms on general positions). Both di-thio-nate ions are completed by crystallographic inversion symmetry. The crystal chosen for data collection was found to be rotationally twinned by 180° about the [100] axis in reciprocal space with a 0.6298 (13):0.3702 (13) domain ratio.

A purple odyssey: synthesis and structure of 3-amino-4-hy-droxy-6-oxo-cyclo-hexa-2,4-dien-1-iminium chloride monohydrate.

In the cation of the title hydrated mol-ecular salt, C6H7N2O2 (+)·Cl(-)·H2O, the six-membered ring shows unequal bond lengths consistent with delocalization of electrons over two separate 6π systems with single bonds between them. In the crystal, the components are linked by N-H⋯Cl, N-H⋯O, O-H⋯Cl and O-H⋯O hydrogen bonds, generating double layers propagating in (100).

Investigations of new potential photo-acid generators: crystal structures of 2-[(E)-2-phenyl-ethen-yl]phenol (ortho-rhom-bic polymorph) and (2E)-3-(2-bromo-phen-yl)-2-phenyl-prop-2-enoic acid.

The title compounds, C14H12O, (I), and C15H11BrO2, (II), were prepared and characterized as part of our studies of potential new photo-acid generators. In (I), which crystallizes in the ortho-rhom-bic space group Pca21, compared to P21/n for the previously known monoclinic polymorph [Cornella & Martin (2013 ▸). Org. Lett. 15, 6298-6301], the dihedral angle between the aromatic rings is 4.35 (6)° and the OH group is disordered over two sites in a 0.795 (3):0.205 (3) ratio. In the crystal of (I), mol-ecules are linked by O-H⋯π inter-actions involving both the major and minor -OH disorder components, generating [001] chains as part of the herringbone packing motif. The asymmetric unit of (II) contains two mol-ecules with similar conformations (weighted r.m.s. overlay fit = 0.183 Å). In the crystal of (II), both mol-ecules form carboxyl-ate inversion dimers linked by pairs of O-H⋯O hydrogen bonds, generating R 2 (2)(8) loops in each case. The dimers are linked by pairs of C-H⋯O hydrogen bonds to form [010] chains.

Crystal structure of a layered coordination polymer based on a 4(4) net containing Cd(2+) ions and 1,5-bis-(pyridin-4-yl)pentane linkers.

The title compound, poly[[di-aqua-bis-[1,5-bis-(pyridin-4-yl)pentane-κ(2) N:N']cadmium] bis-(perchlorate) 1,5-bis-(pyridin-4-yl)pentane ethanol mono-solvate], [Cd(C15H18N2)2(H2O)2](ClO4)2·C15H18N2·C2H6O, is a layered coordination polymer built up from highly squashed 4(4) nets in which the octa-hedral trans-CdO2N4 nodes (Cd site symmetry -1) are linked by the bifunctional ligands, forming infinite (110) sheets. The cationic sheets are charge-balanced by inter-layer perchlorate ions. A free 1,5-bis-(pyridin-4-yl)pentane mol-ecule and an ethanol mol-ecule of crystallization are also found in the inter-sheet region. A number of O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds help to consolidate the layered structure.

Hidden signatures: new reagents for developing latent fingerprints.

Aldehydes substituted with a quaternised pyridinium or quinolinium ring have been investigated for the development of latent fingerprints. Two routes were developed to a novel in situ formed azacyanine dye. This dye might form in the fingerprint where reagents are concentrated but does not form appreciably in solution experiments as evidenced by the lack of an absorption band at 600 nm. N-Alkyl and N-aryl substituted benzimidazole-2-carboxaldehydes give stable fluorescent fingerprints.

Polymeric diaqua(mu(2)-2,2'-bipyrimidinyl-kappa4N1,N1':N3,N3')-di-mu(3)-hydroxy-bis(mu(5)-benzene-1,3,5-tricarboxylato-kappa5O1:O2:O3:O3:O5)tetracobalt(II) dihydrate.

The structure of the title compound, [Co(4)(C(9)H(3)O(6))(2)(OH)(2)(C(8)H(6)N(4))(H(2)O)(2)].2H(2)O, contains three separate species, namely the mu(5)-bridging C(9)H(3)O(6)(3-) anion, the doubly chelating and therefore mu(2)-bridging C(8)H(6)N(4) ligand (bipyrimidine, BPM), and the dihydrated diaquadihydroxy tetranuclear cationic cluster, [Co(4)(OH(-))(2)(H(2)O)(2)](6+).2H(2)O, which lies on a crystallographic centre of symmetry, as does the BPM ligand with, in this case, the centre of symmetry coincident with the midpoint of the C-C bond joining the six-membered rings. Within the cation cluster, the Co atoms of one pair are five-coordinate and those of the other six-coordinate.

Analysis of the association between diabetic nephropathy and polymorphisms in the aldose reductase gene in Type 1 and Type 2 diabetes mellitus.

AIMS: To investigate the association between polymorphisms of the aldose reductase gene and diabetic nephropathy in both Type 1 and Type 2 diabetes mellitus, and to carry out a meta-analysis of published results. METHODS: We have investigated the role of two aldose reductase polymorphisms in four independent cohorts of cases and controls (two each with Type 1 and Type 2 diabetes) drawn from two ethnic populations, including 471 patients with nephropathy and 494 control diabetic patients without nephropathy. A C/T transition at position -106, and a (CA)n microsatellite marker 2.1 kb from the start site of the aldose reductase gene were genotyped in nephropathic patients and non-nephropathic controls from each cohort. RESULTS: Carriage of the -106 T allele was significantly associated with diabetic nephropathy in three of the four study groups. The Mantel-Haenszel combined odds ratio was 2.22 (95% CI 1.69, 2.94), P = 1.05 x 10(-8). We found no evidence for association of the microsatellite marker with nephropathy, despite moderate levels of disequilibrium between the two markers. Meta-analysis of published data yielded no evidence for association of the microsatellite marker with diabetic nephropathy in Type 2 diabetes, but varying degrees of association with diabetic nephropathy in Type 1 diabetes. CONCLUSIONS: Meta-analyses provide more convincing evidence of a role for the ALR2-106 marker than for the microsatellite marker in diabetic nephropathy (DN). More studies are now required to confirm these results and to establish whether the ALR2-106 polymorphism has a functional role in DN.

A new polymorph, form C, of [1,2-bis(diphenylphosphino)ethane]-dichloronickel(II).

The title compound, [NiCl2(C26H24P2)], has arisen as a result of the unexpected reduction (hydrogenation) of the trans-1,2-bis(diphenylphosphino)ethene ligand. The hydrothermal reaction conditions have produced a third polymorphic form of the compound which has twofold symmetry, crystallizes in an enantiomer-selective manner and contains an unexpectedly short C-C (ethane) bond. Contacts of the form C-H...Cl are present, one involving alkyl and the other aryl hydrogen, with C.Cl distances of 3.556 (4) and 3.664 (6) A, respectively.

Solid phase synthesis of tertiary amines on amide REM resins: Grignard and metal hydride compatible resins.

Four new amide REM resins (AM REM 2-5) are described, and their use is illustrated for the synthesis of tertiary amines 6-9 and 13-16. Amide REM resins 4 and 5, which have a phenyl ring attached to the amide nitrogen, are found to give superior product yields and purities, and the resins are stable to a wider range of reagents and conditions compared to REM resin 1.

Design and synthesis of stable, water soluble radicals as potential anti-cancer agents.

A free diazafluorenyl radical based on the Koelsch free radical was designed and synthesized with expectations of stability and water solubility. The novel radical precursors were synthesised from the parent brominated stilbene and the substituted fluorenes in an IPSO substitution, as a key synthetic step. The precursors were deprotonated and the anion was discharged by an aqueous solution of potassium cyanoferrate. The new radicals were prepared from fluorene in 6 steps with good overall yields. These radicals have shown promising anticancer activity in initial screenings on 2 different MAC cell lines.