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New mono-and dinuclear aryltrialkylsilanes and-stannanes [Me 3 M{C 6 H 3 (CH 2 NMe 2) 2-2,6}] (M) Si (5), Sn (6)) and [(Me 3 M) 2-1,4-{C 6 (CH 2 NMe 2) 4-2,3,5,6}] (M) Si (9), Sn (10)) have been prepared from transmetalation reactions of dimeric [Li{C 6 H 3 (CH 2 NMe 2) 2-2,6}] 2 and new polymeric [Li 2-1,4-{C 6 (CH 2 NMe 2) 4-2,3,5,6}] ∞ with (trimethylsilyl)trifluoromethanesulfonate or trimethyltin chloride. The X-ray crystal structures of dinuclear 9 and 10 have been determined and in the molecular geometries found the central 1,4-phenylene dimetalated aryl ligand system provides bidentate C,N-coordination to silicon in 9 and terdentate pseudofacial N,C,N′-coordination to tin in 10. Reactions of the newly prepared silanes 5 and 9 and stannanes 6 and 10 with diverse palladium(II) and platinum(II) substrates afford organometallic products arising from both aryl and methyl group transfer. For example, the reaction of dinuclear stannane 10 (or dinuclear silane 9) with palladium(II) species gives the bimetallic complex [(PdCl) 2-1,4-{C 6 (CH 2 NMe 2) 4-2,3,5,6}] (15), whereas its reaction with [PtCl 2 (COD)] (COD) cycloocta-1,5-diene) or Me 3 SnCl gives the ionic tin(IV) species [(Me 2-Sn) 2-1,4-{C 6 (CH 2 NMe 2) 4-2,3,5,6}] 2+ (X-) 2 with X being Cl (18a) or Me 3 SnCl 2 (18b). The X-ray crystal structure of 18b has been determined and the molecular geometry found shows that the central dimetalated aryl ligand system provides terdentate meridional N,C,N′-coordination to both tin centers.

Fast pyrolysis bio-oils are feasible energy carriers and a potential source of chemicals. Detailed characterization of bio-oils is essential to further develop its potential use. In this study, quantitative 13C nuclear magnetic resonance (13C NMR) combined with comprehensive two-dimensional gas chromatography (GC × GC) was used to characterize fast pyrolysis bio-oils originated from pinewood, wheat straw, and rapeseed cake. The combination of both techniques provided new information on the chemical composition of bio-oils for further upgrading. 13C NMR analysis indicated that pinewood-based bio-oil contained mostly methoxy/hydroxyl (≈30%) and carbohydrate (≈27%) carbons; wheat straw bio-oil showed to have high amount of alkyl (≈35%) and aromatic (≈30%) carbons, while rapeseed cake-based bio-oil had great portions of alkyl carbons (≈82%). More than 200 compounds were identified and quantified using GC × GC coupled to a flame ionization detector (FID) and a time of flight mass spectrometer (TOF-MS). Nonaromatics were the most abundant and comprised about 50% of the total mass of compounds identified and quantified via GC × GC. In addition, this analytical approach allowed the quantification of high value-added phenolic compounds, as well as of low molecular weight carboxylic acids and aldehydes, which exacerbate the unstable and corrosive character of the bio-oil.

A bulky cyclopentadienyl (Cp)-based trioxorhenium compound was developed for the catalytic deoxydehydration of vicinal diols to olefins. The 1,2,4-tri(tert-butyl)cyclopentadienyl trioxorhenium (2) catalyst was synthesised in a two-step synthesis procedure. Dirhenium decacarbonyl was converted into 1,2,4-tri(tert-butyl)cyclopentadienyl tricarbonyl rhenium, followed by a biphasic oxidation with H2 O2 . These two new three-legged compounds with a 'piano-stool' configuration were fully characterised, including their single crystal X-ray structures. Deoxydehydration reaction conditions were optimised by using 2 mol % loading of 2 for the conversion of 1,2-octanediol into 1-octene. Different phosphine-based and other, more conventional, reductants were tested in combination with 2. Under optimised conditions, a variety of vicinal diols (aromatic and aliphatic, internal and terminal) were converted into olefins in good to excellent yields, and with minimal olefin isomerisation. A high turnover number of 1400 per Re was achieved for the deoxydehydration of 1,2-octanediol. Furthermore, the biomass-derived polyols (glycerol and erythritol) were converted into their corresponding olefinic products by 2 as the catalyst.

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