Question
These compounds are commonly used to induce a paramagnetic change in the spins of nearby molecular systems during one technique. For 10 points each:
[10h] Name these non-solvent compounds used to resolve overlapping multiplets. A popularly used one of these compounds is formed from the coordination of three FOD (“fod”) ligands to a europium ion.
ANSWER: chemical shift reagents [accept lanthanide shift reagents; prompt on lanthanides]
[10e] Shift reagents improve the resolution of spectra produced by this technique, which uses a strong magnetic field to flip the spins of a chemical species’s nuclei.
ANSWER: nuclear magnetic resonance spectroscopy [or NMR spectroscopy]
[10m] Because it interacts with R and S enantiomers differently, the shift reagent Eu(hfbc)3 (“europium H-F-B-C-3”) is useful in determining this quantity in an NMR sample. This quantity represents the ratio of R- and S-labelled isomers in a racemic mixture.
ANSWER: enantiomeric excess [or ee; accept optical purity; accept optical activity]
<Kane Nguyen, Chemistry>
Summary
| 2024 Penn Bowl Berkeley | 11/02/2024 | Y | 2 | 15.00 | 100% | 50% | 0% |
| 2024 Penn Bowl CWRU | 11/02/2024 | Y | 4 | 10.00 | 75% | 25% | 0% |
| 2024 Penn Bowl Chicago | 11/02/2024 | Y | 8 | 17.50 | 100% | 63% | 13% |
| 2024 Penn Bowl Mainsite | 11/02/2024 | Y | 3 | 10.00 | 67% | 33% | 0% |
| 2024 Penn Bowl Texas | 11/02/2024 | Y | 2 | 10.00 | 100% | 0% | 0% |
| 2024 Penn Bowl Florida | 10/26/2024 | N | 2 | 5.00 | 50% | 0% | 0% |
| 2024 Penn Bowl Harvard | 10/26/2024 | N | 4 | 12.50 | 100% | 25% | 0% |
| 2024 Penn Bowl Playtest | 10/12/2024 | N | 2 | 25.00 | 100% | 100% | 50% |
| 2024 Penn Bowl UK | 10/26/2024 | N | 5 | 14.00 | 100% | 40% | 0% |
| 2024 Penn Bowl UNC | 10/26/2024 | N | 3 | 13.33 | 100% | 33% | 0% |
Data
| Berkeley A | Berkeley B | 0 | 10 | 0 | 10 |
| Stanford | Berkeley C | 0 | 10 | 10 | 20 |
| Ohio State A | Michigan B | 0 | 10 | 10 | 20 |
| Michigan State | Ohio State C | 0 | 0 | 0 | 0 |
| Carnegie Mellon | Pittsburgh | 0 | 10 | 0 | 10 |
| Michigan A | Ohio State B | 0 | 10 | 0 | 10 |
| Chicago B | Illinois C | 0 | 10 | 10 | 20 |
| Illinois B | Chicago A | 0 | 10 | 10 | 20 |
| WUSTL | Northwestern A | 0 | 10 | 10 | 20 |
| SIUE | Northwestern B | 0 | 10 | 0 | 10 |
| Notre Dame B | Indiana B | 0 | 10 | 10 | 20 |
| Notre Dame C | Minnesota | 0 | 10 | 0 | 10 |
| Illinois A | Purdue | 10 | 10 | 10 | 30 |
| NYU B | Columbia | 0 | 0 | 0 | 0 |
| JHU A | JHU B | 0 | 10 | 10 | 20 |
| NYU A | Maryland | 0 | 10 | 0 | 10 |
| TAMU | Houston | 0 | 10 | 0 | 10 |
| Texas A | Texas B | 0 | 10 | 0 | 10 |
| Indiana A | Notre Dame A | 0 | 10 | 0 | 10 |