Richard Betz

Selective removal of isoquinoline and quinoline from simulated fuel using 1,1′-binaphthyl-2,2′-diol (BINOL): crystal structure and evaluation of the adduct electronic properties

1,1′-Binaphthyl-2,2′-diol/quinoline (BINOL/QUN) and 1,1′-binaphthyl-2,2′-diol/isoquinoline (BINOL/ISOQUN) adducts were successfully synthesized. X-ray single crystals of BINOL/QUN and BINOL/ISOQUN were grown and analysed. The crystal packing of the molecules in both adducts confirmed that they are held in aggregates by strong hydrogen bonds (O2–H2⋯O3), (O3–H3⋯N1), (O2–H2⋯O1), (O1–H1⋯N1), (O2–H2⋯O1) and weak hydrogen C–H⋯π bonds. The patterns of the hydrogen bonding network as well as the conformation of BINOL contribute to the formation of the shape of the voids that entrap quinoline and isoquinoline. Molecular modelling which was employed to investigate the electronic properties of BINOL/QUN and BINOL/ISOQUN shows that the HOMO positions of the adducts are localized around the 1,1′-binaphthyl-2,2′-diol (BINOL), while the LUMO is positioned on isoquinoline and quinoline. Thermodynamic parameters obtained from isothermal titration calorimetry (ITC) revealed a stronger isoquinoline/BINOL interaction compared to quinoline/BINOL. 6-Vinyl-1,1′-binaphthyl-2,2′-diol was co-polymerized with styrene to form [DBN-co-STY]. Electrospun [DBN-co-STY] exhibited selectivity for quinoline and isoquinoline in a model simulated fuel presenting an adsorption capacity of 2.2 and 2.4 mg g−1 respectively. The adsorption study showed a higher adsorption capacity for isoquinoline compared to quinoline. This may be attributed to the more favourable electronic properties (HOMO–LUMO properties) of isoquinoline. This concept demonstrates the possibility of extracting/separating isoquinoline and quinoline from fuel.

pH-metric chemical speciation modeling and studies of in vitro antidiabetic effects of bis[(imidazolyl)carboxylato]oxidovanadium(IV) complexes.

A range of bidentate N,O-donor ligands of the imidazolyl-carboxylate moiety, which partially mimic naturally occurring bioligands, were prepared and reacted with the oxidovanadium(IV) ion to form the corresponding bis-coordinated oxidovanadium(IV) complexes. The aqueous pH-metric chemical speciation was investigated using glass electrode potentiometry, which allowed for the determination of protonation and stability constants of the ligands and complexes, respectively. The species distribution diagrams generated from this information gave evidence that the bis[(imidazolyl)carboxylato]oxovanadium(IV) complexes possess a broad pH-metric stability. The complexes improved glucose uptake in cell cultures using 3T3-L1 adipocytes, C2C12 muscle cells and Chang liver cells. The PTP inhibition studies indicated that the mechanism underlying insulin-stimulated glucose uptake was possibly via the protein tyrosine phosphorylation through the inhibition of the protein tyrosine phosphatase 1B (PTP 1B). The vanadium compounds also demonstrated the inhibition of D-dimer formation, suggesting that these compounds could potentially relieve a hypercoagulative state in diabetic patients.

4-[Bis(4-fluoro­phen­yl)meth­yl]-1-[(2E)-3-phenyl­prop-2-en-1-yl]piperazin-1-ium 3-carb­oxy­propano­ate

In the title salt, C26H27F2N2 +·C4H5O4 −, the piperazine N atom bearing the vinylic substituent is protonated. The piperazine ring adopts a chair conformation. In ther crystal, the succinate monoanions are connected via short O—H⋯O hydrogen bonds between the carboxylic acid and carboxylate groups into undulating chains extending along [001] and the flunarizinium monocations are attached to these chains via N+—H⋯O− hydrogen bonds. C—H⋯O interactions connect these chains into a three-dimensional network. The shortest centroid–centroid distance of 3.7256 (10) Å was found between one of the fluorinated benzene rings and the non-fluorinated phenyl ring in the neighbouring molecule related by a glide plane.

4-(4-Iodo­anilino)-2-methyl­ene-4-oxo­butanoic acid

In the title compound, C11H10INO3, an addition product of itaconic acid anhydride and 4-iodoaniline, the least-squares planes defined by the atoms of the aromatic moiety and the non-H atoms of the carboxylic acid group enclose an angle of 74.82 (11)°. In the crystal, classical O—H⋯O hydrogen bonds formed by carboxylic groups, as well as N—H⋯O hydrogen bonds formed by amide groups, are present along with C—H⋯O contacts. Together, these connect the molecules into dimeric chains along the b-axis direction.

6-Amino-1,3-dimethyl-5-[(E)-2-(methyl-sulfan-yl)benzyl-idene-amino]-pyrimidine-2,4(1H,3H)-dione.

The title compound, C14H16N4O2S, is a Schiff base derivative of 2-(methylsulfanyl)benzaldehyde. The configuration about the C=N double bond is E. The heterocyclic ring is essentially planar (τ = 3.1°) and makes a dihedral angle of 12.24 (7)° with the benzene ring. An intramolecular N—H⋯S hydrogen bond is observed. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds link molecules into layers perpendicular to [101]. The closest distance between the centroids of two heterocyclic rings was found to be 3.5268 (8) Å.

2-Chloro-1,2-diphenyl-ethanone (desyl chloride).

The title compound, C14H11ClO, is a racemic derivative of benzoin. Its carbonyl group adopts a nearly eclipsed conformation with the Cl substituent characterized by a dihedral angle of 17.5 (2)°. The closest intermolecular π–π contact is 4.258 (1) Å.

4-[Bis(4-fluorophenyl)methyl]piperazin-1-ium picrate.

The title compound {systematic name: 4-[bis(4-fluorophenyl)methyl]piperazin-1-ium 2,4,6-trinitrophenolate}, C17H19F2N2 +·C6H2N3O7 −, is the picrate salt of a piperazine-supported amine bearing a benzhydryl substituent on one of its N atoms. During co-crystallisation, protonation took place on the N atom of the secondary amine functionality. The non-aromatic six-membered heterocycle adopts a chair conformation. In the crystal, N—H⋯O hydrogen bonds as well as C—H⋯O contacts connect the components into a three-dimensional network.

Pyridine-2,3-diamine

The molecule of the title pyridine derivative, C5H7N3, shows approximately non-crystallographic C s symmetry. Intracyclic angles cover the range 117.50 (14)–123.03 (15)°. In the crystal, N—H⋯N hydrogen bonds connect molecules into a three-dimensional network. The closest intercentroid distance between two π-systems occurs with the c-axis repeat at 3.9064 (12) Å.

3-Nitro­benzene-1,2-diamine

The molecule of the title compound, C6H7N3O2, a derivative of o-phenylenediamine, nearly shows non-crystallographic C s symmetry. C—C—C angles span the range 116.25 (11)–122.35 (11)°. In the crystal, intermolecular N—H⋯O and N—H⋯N hydrogen bonds connect molecules into undulating sheets perpendicular to the crystallographic a axis. A weak intramolecular N—H⋯O hydrogen bond is also observed. No π-stacking is observed in the crystal structure.

1,3-Diethyl-1,3-diphenyl­urea

The molecule of the title compound, C17H20N2O, a symmetrical derivative of urea, shows non-crystallographic C 2 symmetry. Interaction with the aromatic system of the phenyl substituents as well as amide-type resonance is responsible for the marked planarization of the coordination environments of the N atoms. C—H⋯O contacts give rise to the formation of centrosymmetric dimers in the crystal structure. The closest distance between the centroids of two adjacent rings is 3.8938 (11) Å.