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A switchable hydrophilicity solvent (SHS) was studied for its effectiveness at extracting lipids from freeze-dried samples of Botryococcus braunii microalgae. The SHS N , N -dimethylcyclohexylamine extracted up to 22 wt.% crude lipid relative to the freeze-dried cell weight. The solvent was removed from the extract with water saturated with carbon dioxide at atmospheric pressure and recovered from the water upon de-carbonation of the mixture. Liquid chromatography–mass spectrometry (LC–MS) showed that the extracted lipids contained high concentrations of long chain tri-, di- and mono-acylglycerols, no phospholipids, and only 4–8% of residual solvent. Unlike extractions with conventional organic solvents, this new method requires neither distillation nor the use of volatile, flammable or chlorinated organic solvents.

The catalytic utility of [κ2-{3-iPr2P-2-O-indene}Rh(COD)] (COD = η4−1,5-cyclooctadiene) 1a in the hydroformylation of styrenes was examined. Complex 1a was shown to be an effective pre-catalyst in benzene and tetrahydrofuran, exhibiting good conversions to aldehyde and high branched-to-linear selectivity for styrene, 4-chlorostyrene, and 4-methylstyrene under reasonably mild conditions (1000 psi syngas; 1.8 mol% Rh, 45 °C, 2–5 h). Under analogous conditions, the iridium congener of 1a proved inactive for hydroformylation. The synthesis and crystallographic characterization of the new complex [κ2-{2-iPr2PC6H4O}Rh(COD)] 2 is also reported; the catalytic performance of 2 in the hydroformylation of styrene was found to be comparable to that of 1a under similar catalytic conditions.

Several tertiary amines serve as switchable-hydrophilicity solvents, meaning that they are hydrophobic solvents having very low miscibility with water when under air but hydrophilic solvents having complete miscibility with water when under an atmosphere of CO2. Unlike the only previously reported switchable-hydrophilicity solvent, these amines are easily prepared and, in some cases, commercially available. The effect of temperature, gas flow rates, choice of amine and additives on the switching process is described. These solvents can be applied to the recycling of polystyrene foam.