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The exhaustive methylation of the three isomers of the icosahedral carboranes 1,2-, 1,7-, and 1,12-dicarbadodecaborane(12) (ortho-(1), meta-(2), and para-carborane (3)) under Friedel ± Crafts conditions using MeI/AlCl 3 is described. Regioselectively ortho-and meta-carborane are octamethylated providing 4,5,7,8,9,10,11,12-octamethyl-1,2-dicarba-closo-dodecaborane(12) (6) and 4,5,6,8,9,10,11,12-octamethyl-1,7-dicarba-closo-dodecaborane(12) (8) in high yield. Their BH vertices adjacent to both CH vertices remain unmethylated. Paracarborane can be quantitatively converted to its deca-B-methyl derivative 4.

Diesel fuel emulsions have demonstrated reductions of unwanted combustion emissions. Glycerol, a renewable and abundant resource, is an attractive fuel component because it is a low-cost energy source. In this paper, the glycerol−diesel emulsion system is characterized and resultant fuel properties are presented. Surface analytical techniques and long-term stability evaluations are used to identify optimal surfactant composition. Emulsions are prepared using batch ultrasonic processing to produce a narrow droplet size distribution with a mean of approximately 3.3 μm. The glycerol water content tends to increase the droplet size distribution. Glycerol−diesel emulsions prepared at 10 and 20 vol % glycerol phase are combusted in a naturally aspirated single-cylinder diesel engine. Oxides of nitrogen and particulate matter emissions are reduced by 5−15 and 25−50%, respectively. Indicated fuel consumption is increased corresponding to an increased glycerol concentration because of a reduction in the emulsion energy density. Thermal efficiency improvements are observed at high loads.

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