Abstract
Several types of previously unobserved long- and short-range spin couplings in closo-2,4-C2B5H7, and some of its derivatives, are reported. Values for these couplings, obtained from resolution-enchanced proton and boron-11 NMR spectra, fall in the following ranges: 8-19 Hz for 3J(H7,B1) or 2J(H7,B3); 1.51-2.05 Hz for 4J(H2,H5) and 4J(H4,H6); 2.76-4.63 Hz for 4J(H2,H4); 0.43-0.73 Hz for 3J(H1,H5), 3J(H1,H6), 3J(H7,H5), and 3J(H7,H6); 25-42 Hz for 1J(11B5,11B6). The 1H,1H coupling values have been derived from NMRENIT analyses of the observed 1H{11B,10B} patterns; additionally much improved values of some previously reported couplings and chemical shifts have been obtained for the various derivatives of this carborane system. For 1,5,6-(CH3)3-2,4-C2B5H4, 2J(Hapex melhyl,B1) = 6 Hz and 5J(Hapex methyl, H7) or 4J(apex melhyl,H3) = 0.4 Hz.
| Original language | English |
|---|---|
| Pages (from-to) | 399-405 |
| Number of pages | 7 |
| Journal | Journal of Magnetic Resonance (1969) |
| Volume | 59 |
| Issue number | 3 |
| DOIs | |
| State | Published - 1 Oct 1984 |
Bibliographical note
Funding Information:The authors thank the National Science Foundation and the National Institutes of Health, MBRS program (C.G. and S.L.) for partial support of this study. Some of the equipment modifications on the Bruker WP-60 instrument required to carry out the triple-resonance studies were made by R. Penigan. The “B NMR data were obtained using a Bruker WM-500 instrument at the Southern California Regional NMR facility at the California Institute of Technology, funded by NSF Grant CHE-7916324. The NMRENIT program was provided by D. Manatt and S. Manatt.