NMR studies of chemical structural variation of insoluble organic matter from different carbonaceous chondrite groups

Details NMR studies of chemical structural variation of insoluble organic matter from different carbonaceous chondrite groups NMR studies of chemical structural variation of insoluble organic matter from different carbonaceous chondrite groups

Feb 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005gecoa..69.1085c&link_type=abstract

Geochimica et Cosmochimica Acta, Volume 69, Issue 4, p. 1085-1097.

Other

75

Scientific paper

Solid-state 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopic experiments have been performed on isolated meteoritic Insoluble Organic Matter (IOM) spanning four different carbonaceous chondrite meteorite groups; a CR2 (EET92042), a CI1 (Orgueil), a CM2 (Murchison), and the unique C2 meteorite, Tagish Lake. These solid state NMR experiments reveal considerable variation in bulk organic composition across the different meteorite group’s IOM. The fraction of aromatic carbon increases as CR2 < CI1 < CM2 < Tagish Lake. The increases in aromatic carbon are offset by reductions in aliphatic (sp3) carbon moieties, e.g., “CHx,” and “CHx(O,N).” Oxidized sp2 bonded carbon, e.g., carboxyls and ketones grouped as “CO,” are largely conservative across these meteorite groups. Single pulse (SP) 13C magic angle spinning (MAS) NMR experiments reveal the presence of nanodiamonds with an apparent concentration ranking in the IOM of CR2 < CI1 < CM2 < Tagish Lake. A pair of independent NMR experiments reveals that, on average, the aromatic moieties in the IOM of all four meteoritic IOM fractions are highly substituted. Fast spinning SP 1H MAS NMR spectral data combined with other NMR experimental data reveal that the average hydrogen content of sp3 bonded carbon functional groups is low, requiring a high degree of aliphatic chain branching in each IOM fraction. The variation in chemistry across the meteorite groups is consistent with alteration by low temperature chemical oxidation. It is concluded that such chemistry principally affected the aliphatic moieties whereas the aromatic moieties and nanodiamonds may have been largely unaffected.

Affiliated with

Also associated with

No associations

Rating

NMR studies of chemical structural variation of insoluble organic matter from different carbonaceous chondrite groups does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with NMR studies of chemical structural variation of insoluble organic matter from different carbonaceous chondrite groups, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and NMR studies of chemical structural variation of insoluble organic matter from different carbonaceous chondrite groups will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1358930