Cometary Glycolaldehyde as a Source of pre-RNA Molecules.

Over 200 molecules have been detected in multiple extraterrestrial environments, including glycolaldehyde (C(HO), GLA), a two-carbon sugar precursor that has been detected in regions of the interstellar medium. Its recent detection on the nucleus of comet 67P/Churyumov-Gerasimenko and through remote observations in the comae of others provides tantalizing evidence that it is common on most (if not all) comets. Impact experiments conducted at the Experimental Impact Laboratory at NASA's Johnson Space Center have shown that samples of GLA and GLA mixed with montmorillonite clays can survive impact delivery in the pressure range of 4.

Building blocks for molecule-based magnets: radical anions and dianions of substituted 3,6-dimethylenecyclohexane-1,2,4,5-tetrones as paramagnetic bridging ligands.

We have prepared four tetraaryl derivatives of 3,6-dimethylene-1,2,4,5-tetraoxocyclohexane (aryl = Ph; 4-MeOPh; 4-Me(2)NPh; and 3,5-(t-Bu)(2)-4-MeOPh) with guidance from an earlier reported ab initio analysis (Misiolek, A. W.; Jackson, J.

Time-resolved EPR studies of main chain radicals from acrylic polymers. Effects of tacticity, solvent, and side group structure on chain stiffness.

Main chain polymeric radicals from several acrylic polymers, produced by laser flash photolysis at 248 nm in liquid solution, have been studied using direct detection time-resolved electron paramagnetic resonance (TREPR) spectroscopy at 9.5 GHz. Highly isotactic poly(methyl methacrylate) (i-PMMA) shows a sharp, well-resolved spectrum at about 95 degrees C.

Chemically induced dynamic electron spin polarization-detected energy transfer. Substrate size effects and solvent dependence.

Time-resolved electron paramagnetic resonance spectroscopy is used to probe energy transfer from aromatic photoexcited triplet states to azo compounds in liquid solution. The observation of chemically induced dynamic electron spin polarization in the spectra gives precise information regarding the spin physics and mechanism of the energy transfer process. The substrate size is varied by altering the chain length of alkyl chains covalently attached to the azo compounds via ester or amide linkages.