The Tagish Lake meteorite fell last year on a frozen lake in Canada and may provide the most pristine material of its kind. Analyses have now shown this carbonaceous chondrite to contain a suite of soluble organic compounds (approximately 100 parts per million) that includes mono- and dicarboxylic acids, dicarboximides, pyridine carboxylic acids, a sulfonic acid, and both aliphatic and aromatic hydrocarbons. The insoluble carbon exhibits exclusive aromatic character, deuterium enrichment, and fullerenes containing "planetary" helium and argon. The findings provide insight into an outcome of early solar chemical evolution that differs from any seen so far in meteorites.
Understanding the effect of pressure on aluminosilicate glass and liquid structure is critical to understanding magma flow at depth. Aluminum coordination has been predicted by mineral phase analysis and molecular dynamic calculations to change with increasing pressure. Nuclear magnetic resonance studies of glasses quenched from high pressure provide clear evidence for an increase in the average coordination of Al with pressure.
Ionic liquids based on various chelated orthoborate anions of different N-containing onium cations have been
synthesized using an economic synthesis strategy. Most orthoborates do not crystallize. They are found to
have much higher glass transition temperatures and room-temperature viscosities than those with perfluorinated
anions such as TFSI-, BF4
-, and CF3SO3
- (Tf-), as predicted from anion polarizability arguments. The ambient
conductivities of the new ionic liquids are low relative to those with perfluorinated anions. The transport
properties all show that cohesion in these liquids increases, and ionic mobilities decrease, as anion size increases,
implying that van der Waals interactions, not Coulomb interactions, have become the controlling influence.
In view of their resistance to crystallization, the large range of temperature over which these liquids can be
studied, their hydrophobic properties, and their high fragilities, these liquids may provide good model systems
for fundamental liquid state investigations and interesting solvents for large-molecule dissolution.
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