One-step Preparation of Carbon-based Solid Acid Catalyst from Water Hyacinth Leaves for Esterification of Oleic Acid and Dehydration of Xylose.

Carbon-based solid acid catalysts were successfully obtained via one-step hydrothermal carbonization (HTC) of water hyacinth (WH) in the presence of p-toluenesulfonic acid (PTSA). Increasing the HTC temperature from 180 to 240 °C resulted in carbonaceous materials with increased sulfur content and less adsorbed water. The material obtained at 220 °C (WH-PTSA-220) contains the highest amount of acid sites and promotes the highest initial rate of two transformations, that is, methanolysis of oleic acid and dehydration of xylose to furfural. While all PSTA-treated WH catalysts gave comparable fatty acid conversions (≈97 %) and furfural yields (≈60 %) after prolonged reaction times, the WH-PTSA-240 system bearing a relatively low acid density maintains the most favorable reusability profile. Higher HTC temperatures (220-240 °C) improved the catalyst reusability profiles due to graphitization and hydrophobicity of the carbon surface. The catalyst systems derived herein from biomass may have potential applications in biorefining platforms, utilizing the conversion of waste biomass to chemicals.

Transesterification of soybean oil using bovine bone waste as new catalyst.

Calcined bovine bone waste was employed to catalyze the transesterification reaction between soybean oil and methanol. The influence of various conditions on the efficiency of the transesterification was studied i.e. type of reactor, temperature, catalyst loading and methanol/oil ratio. The optimum yield of methyl ester (97%) was obtained by performing the closed-system transesterification at 65 °C for 3 h with catalyst loading of 8% wt and 6:1 methanol to oil ratio, using bone calcined at 750 °C. Calcination of the commercial bovine bone at 650 °C and above results in conversion of the calcium carbonate component to calcium oxide, with the major component being crystalline hydroxyapetite. Calcium oxide is believed to be responsible for the catalytic activity of the material. The reusability, low cost and low catalyst loading required (4% wt) may make bovine bone an attractive alternative to existing transesterification catalyst systems.

A Users' Guide to 'Juice Bars' and 'Liquid Handcuffs': Fluid Negotiations of Subjectivity, Space and the Substance of Methadone Treatment.

The contested space of addiction treatment is a space of intersections and inscriptions, a space where the biopolitics of treatment practice meets strategies of sociospatial stigmatization projected by the surrounding community. Drawing from a case study of community conflict surrounding the relocation of a methadone clinic into Corktown, a rapidly gentrifying neighborhood on the peripheries of downtown Toronto, this articles explores the sociospatial dimensions of addiction treatment through a theoretical and ethnographic investigation of client impressions regarding the space of the methadone clinic, before and after its relocation into Corktown. Examining clients' engagement with the space of the clinic as a series of body-space "assemblages" and "folds," this analysis reveals the clinic as an inherently social space, where clients negotiate both the fluid strategies of biopolitical control implicated in treatment practice, and strategies of sociospatial stigmatization in order to assert and articulate their "right to the city."

Socio-spatial stigmatization and the contested space of addiction treatment: remapping strategies of opposition to the disorder of drugs.

In recent years, the Not-In-My-Back-Yard (NIMBY) phenomenon has become increasingly prevalent with regard to harm reduction sites, addiction treatment facilities and their clients. Drawing from a case study of community conflict generated by the relocation of a methadone clinic into a rapidly gentrifying neighbourhood in downtown Toronto, Canada, this article offers a unique analysis of oppositional strategies regarding the perceived (socio-spatial) 'disorder of drugs'. Based on interviews with local residents and business owners this article suggests the existence of three interrelated oppositional strategies, shifting from a recourse to urban planning policy, to a critique of methadone maintenance treatment (MMT) practice, to explicit forms of socio-spatial stigmatization that posited the body of the (methadone) 'addict' as abject agent of infection and the clinic as a site of contagion. Exploring the dialectical, socio-spatial interplay between the body of the addict and the social body of the city, this article demonstrates the unique aspects of opposition to the physically, ideologically and discursively contested space of addiction treatment. Representations of the methadone clinic, its clients and the larger space of the neighbourhood, this paper suggests, served to situate addiction as a 'pathology (out) of place' and recast the city itself as a site of safe/supervised consumption.

Structural development of free or coordinated 4'-(4-pyridyl)-2,2':6',2''-terpyridine ligands through N-alkylation: new strategies for metallamacrocycle formation.

A series of N-alkylated derivatives of [Ru(pytpy)(2)]2+ (pytpy=4'-(4-pyridyl)-2,2':6',2''-terpyridine) has been synthesised and characterised. These include both model and functionalised complexes that complement previously reported iron(II) analogues. Reaction of [Ru(pytpy)(2)]2+ with bis[4-(bromomethyl)phenyl]methane leads to the formation of a [2+2] ruthenamacrocycle. Related ferramacrocycles could not be accessed by this route, and instead were prepared in two steps by first reacting bis[4-(bromomethyl)phenyl]methane or 4,4'-bis(bromomethyl)biphenyl with two equivalents of pytpy, and then treating the resulting bis(N-alkylated) product with iron(II) salts.

Lanthanide-induced helical arrays of [{Co(III) sepulchrate} intersection {p-sulfonatocalix[4]arene}] supermolecules.

In the presence of lanthanide ions, a Co(III) sepulchrate cation [Co(diHOsar)]3+ and sodium p-sulfonatocalix[4]arene form a 1:1 host-guest complex which is self-assembled into a zeolite-like lattice network comprised of parallel, single stranded helices.

Formation of [2 + 2] diruthenium(II) metallomacrocycles from ligands containing 2,2':6',2''-terpyridine domains linked through flexible polyethyleneoxy spacers.

The syntheses of three ligands containing two terpy metal-binding domains linked through flexible polyethyleneoxy spacers are described. These ligands have been utilised as building blocks in a two-step process for the formation of a series of dinuclear ruthenium(II) metallomacrocycles of the type [Ru2L2]4+. Employing a two-step methodology allows the formation of homoleptic ([Ru2L2]4+) and heteroleptic ([Ru2LL']4+) species in which the ligands differ in the length of the polyethyleneoxy spacer connecting each terpy motif. Homoleptic metallomacrocycles have been characterised through single crystal X-ray diffraction studies, while 2D-NMR spectroscopy has been employed for the characterisation of the heteroleptic species.

Lambda-[1,4,7,10-tetrakis[(S)-2-hydroxypropyl-kappaO]-1,4,7,10-tetraazacyclododecane-kappa4N]cadmium(II) bis(2,4,6-trinitrophenolate) acetonitrile solvate.

Crystallization of [Cd(S-thpc12)](ClO(4))(2) x H(2)O [S-thpc12 is 1,4,7,10-tetrakis[(S)-2-hydroxypropyl]-1,4,7,10-tetraazacyclododecane] in the presence of two equivalents of sodium picrate monohydrate (sodium 2,4,6-trinitrophenolate monohydrate) diastereoselectively produces a neutral receptor complex, viz. the title compound, lambda-[Cd(C(20)H(44)N(4)O(4))](C(6)H(2)N(3)O(7))(2) x CH(3)CN. In this complex, two picrate anions hydrogen bond, via their phenolate moieties, to the pendant hydroxyl groups of the receptor which, together with the four N atoms, themselves bond to Cd(II) in an approximately cubic arrangement. One picrate anion hydrogen bonds to all four hydroxyl groups, one of which also acts as the sole hydrogen-bond donor to the second picrate anion.

Formation of a [1 + 1] metallomacrocycle from a heterotritopic ligand containing two terpy and one bipy metal-binding domains.

Reaction of the heterotritopic ligand L, which contains one bipy and two terpy metal-binding domains linked by a flexible spacer with iron(II) chloride results in the formation of a [1 + 1] metallomacrocycle.

Metal ion-dependent molecular inclusion chemistry: inclusion of aromatic anions by coordinated 1,4,7,10-tetrakis((S)-2-hydroxy-3-phenoxypropyl)-1,4,7,10-tetraazacyclododecane.

The ability of the pendant donor macrocyclic ligand 1,4,7,10-tetrakis((S)-2-hydroxy-3-phenoxypropyl)-1,4,7,10-tetraaza- cyclododecane((S)-thphpc12) (or [Cd((S)-thphpc12)](2+)) to act as a metal ion-dependent receptor for aromatic anions has been investigated in solution and in the solid state. [Cd((S)-thphpc12)](2+) adopts a stable conical conformation with a large hydrophobic cavity, which has been shown to contain, via complementary multiple hydrogen bonding, p-nitrophenolate, aromatic carboxylates, p-toluenesulfonate, certain aromatic amino acid anions, phenoxyacetate, and acetate. In the case of p-nitrophenolate only, one or two anions can be contained within the receptor cavity. The crystal structure of [Cd((S)-thphpc12)(p-nitrophenolate)(2)] shows a coplanar arrangement of the p-nitrophenolates, where each is retained in the cavity by a pair of hydrogen bonds to cis hydroxyl groups. The crystal structure of the p-aminobenzoate inclusion complex indicates retention of the guest via a pair of hydrogen bonds to each oxygen atom of the carboxylate moiety. The crystal structure of the (L)-phenylalaninate inclusion complex indicates that the amino acid is retained by five hydrogen bonds, two involving the nitrogen atom and three to the oxygen atoms of the carboxylate moiety. Binding constants (10(3)-10(5) M(-1)) for the inclusion of some of the aforementioned anions in [Cd((S)-thphpc12)](2+) and related receptors were measured by (1)H NMR titration in DMSO-d(6) at 298 K.

Metal Ion Dependent Molecular Inclusion Chemistry: Inclusion of p-Toluenesulfonate and p-Nitrophenolate within the Structure of Coordinated 1,4,7,10-Tetrakis((S)-2-hydroxy-3-phenoxypropyl)-1,4,7,10-tetraazacyclododecane.

The pendant donor macrocyclic ligand 1,4,7,10-tetrakis((S)-2-hydroxy-3-phenoxypropyl)-1,4,7,10-tetraazacyclododecane ((S)-thphpc12) has been synthesized in quantitative yield from cyclen (1,4,7,10-tetraazacyclododecane) and (2S)-(+)-3-phenoxy-1,2-epoxypropane. An X-ray diffraction study supports the result of molecular orbital calculations in showing that complexation with hydrated cadmium(II) diperchlorate produces an approximately square-antiprismatic complex in which the metal ion is located between a plane containing the four nitrogen atoms and a plane containing the four oxygen atoms. As a consequence of this the four phenoxymethyl moieties, each attached to one of the four N-O chelate rings, juxtapose to form a substantial empty cavity allowing the complex to act as a molecular receptor. Inclusion complexes have been formed from this complex in which either a p-toluenesulfonate or p-nitrophenolate anion has entered the cavity. An X-ray crystallographic study of [Cd((S)-thphpc12)(p-toluenesulfonate)]ClO(4) shows that the guest anion is retained within the cavity by four hydrogen bonds to the group of hydroxyl moieties associated with the ligand. (13)C NMR and conductivity studies indicate that this inclusion complex retains its integrity in DMSO or DMF solution. Parallel studies have been conducted with [Pb((S)-thphpc12)](ClO(4))(2) indicating that the corresponding inclusion complexes are of lower stability.