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This study presents preliminary experimental data suggesting that sodium 4-(pyrene-1-yl)butane-1-sulfonate (PBSA), 5, an analogue of sodium pyrene-1-sulfonate (PSA), 1, enhances the stability of aqueous reduced graphene oxide (RGO) graphene dispersions. We find that RGO and exfoliated graphene dispersions prepared in the presence of 5 are approximately double the concentration of those made with commercially available PSA, 1. Quantum mechanical and molecular dynamics simulations provide key insights into the behavior of these molecules on the graphene surface. The seemingly obvious introduction of a polar sulfonate head group linked via an appropriate alkyl spacer to the aromatic core results in both more efficient binding of 5 to the graphene surface and more efficient solvation of the polar head group by bulk solvent (water). Overall, this improves the stabilization of the graphene flakes by disfavoring dissociation of the stabilizer from the graphene surface and inhibiting reaggregation by electrostatic and steric repulsion. These insights are currently the subject of further investigations in an attempt to develop a rational approach to the design of more effective dispersing agents for rGO and graphene in aqueous solution.

Fluorescent markers are critical for tracking the position and movement of molecules both in vivo and in vitro. Conventionally, synthetic dyes are non-covalently added to polymers for fluorescent tracking but often diffuse away. Here we demonstrate, for the first time, a facile method for the synthesis of fluorescent polylactic acid PLA nano/-microfibres for biomedical applications using solution spin blowing (SBS). Pyrene end capped poly(L-lactide) (PLLA) derivatives were synthesised using the ring opening polymerisation of L-lactide and their characterisation using spectroscopic and thermal analysis. Submicron-sized fluorescent fibres were produced from these PLLA derivatives using solution blow spinning techniques generating polymer blends and core-shell fibres. Such system could be further exploited to incorporate electrically conductive carbon allotropes via the pyrene aromaticity, producing fluorescent and electrically active fibres for in vitro monitoring and electrical stimulation.

The family of silicatein enzymes from marine sponges (phylumPorifera) is unique in nature for catalyzing the formation of inorganicsilica structures, which the organisms incorporate into theirskeleton. However, the synthesis of organosiloxanes catalyzedby these enzymes has thus far remained largely unexplored. Inorder to investigate the reactivity of these enzymes in relationto this important class of compounds, their catalysis of Si-O bondhydrolysis and condensation was investigated with a range ofmodel organosilanols and silyl ethers. The enzymes’ kinetic parameterswere obtained by a high throughput colorimetric assaybased on the hydrolysis of 4-nitrophenyl silyl ethers. These assaysshowed unambiguous catalysis with kcat/KM values in the orderof 2–50 min−1μM−1. Condensation reactions were also demonstratedby the generation of silyl ethers from their correspondingsilanols and alcohols. Notably, when presented with a substratebearing both aliphatic and aromatic hydroxy groups the enzymepreferentially silylates the latter group, in clear contrast to nonenzymaticsilylations. Furthermore, the silicateins are able to catalyzetransetherifications, where the silyl group from one silylether may be transferred to a recipient alcohol. Despite closesequence homology to the protease cathepsin L, the silicateinsappear to exhibit no significant protease or esterase activity whentested against analogous substrates. Overall, these results suggestthe silicateins are promising candidates for future elaboration intoefficient and selective biocatalysts for organosiloxane chemistry.

The use of Scholl-type reactions on 4,10-di-substituted chrysene derivatives proceeds via variegated, and unexpected oxidation/coupling pathways. These observations serve as a cautionary note when attempting to employ the Scholl reaction in target-oriented, materials, synthesis.

The reaction between 3,6,9-trithia-1(2,6)-pyridinacyclodecaphane and representative group 10 and 11 metal salts [Cu(NO3)2, NiCl2 or Ag(CF3CO2 )] afforded 1:1 complexes which in the case of Cu(II) and Ag(I) were characterized by single crystal X-ray crystallography. The catalytic activity of these complexes in A3-coupling reactions between aldehydes, terminal alkynes and amines was assessed in both protic (water) and aprotic (toluene) media. These A3-reactions prove to be more efficient, proceed with lower catalyst loadings and with faster reaction rates, when conducted in a focused microwave reactor as compared to the same reactions promoted by standard, thermal, modes of activation

The application of a new benzannulation reaction for the regiocontrolled synthesis of functionalized chrysenes is reported. The initial benzannulation and the subsequent halogen displacement reactions are both highly regiospecific, which thereby enables the regiocontrolled synthesis of a variety of 4,10-disubstituted chrysenes from commercially available 1,5-dihydroxynaphthalene.

The title copper(II) complex, {(C27H37N2)[Cu4(CH3COO)8Cl]·3CH2Cl2} n , is a one-dimensional coordination polymer. The asymmetric unit is composed of a copper(II) tetra-acetate paddle-wheel complex, a Cl(-) anion situated on a twofold rotation axis, half a 1,3-bis-(2,6-diisoprop-ylphenyl)imidazolium cation (the whole mol-ecule being generated by twofold rotation symmetry) and one and a half of a di-chloro-methane solvent mol-ecule (one being located about a twofold rotation axis). The central metal-organic framework comprises of a tetra-nuclear copper(II) acetate 'paddle-wheel' complex which arises from the dimerization of the copper(II) tetra-acetate core comprising of three μ2-bidentate acetate and one μ3-tridentate acetate ligands per binuclear paddle-wheel complex. Both Cu(II) atoms of the binuclear component adopt a distorted square-pyramidal coordination geometry (τ = 0.04), with a Cu⋯Cu separation of 2.6016 (2) Å. The apical coordination site of one Cu(II) atom is occupied by an O atom of a neighbouring acetate bridge [Cu-O = 2.200 (2) Å], while that of the second Cu(II) atom is occupied by a bridging chloride ligand [Cu⋯Cl = 2.4364 (4) Å]. The chloride bridge is slightly bent with respect to the Cu⋯Cu inter-nuclear axis [Cu-Cl-Cu = 167.06 (6)°] and the tetra-nuclear units are located about a twofold rotation axis, forming the one-dimensional polymer that propagates along [101]. Charge neutrality is maintained by the inclusion of the 1,3-bis-(2,6-diisoprop-ylphenyl)imidazolium cation within the crystal lattice. In the crystal, the cation and di-chloro-methane solvent mol-ecules are linked to the coordin-ation polymer by various C-H⋯O and C-H⋯Cl hydrogen bonds. There are no other significant inter-molecular inter-actions present.

A generic approach to the regiospecific synthesis of halogenated polycyclic aromatics is made possible by the one- or two-directional benzannulation reactions of readily available (ortho-allylaryl)trichloroacetates (the “BHQ” reaction). Palladium-catalysed cross-coupling reactions of the so-formed haloaromatics enable the synthesis of functionalised polycyclic aromatic hydrocarbons (PAHs) with surgical precision. Overall, this new methodology enables the facile mining of chemical space in search of new electronic functional materials.