Application of line narrowing to boron-11 nuclear magnetic resonance spectra

Boranes. XLV. Crystal and molecular structure, improved synthesis, and reactions of tridecaborane(19)

“…No triplets due to -BH2 groups are observed in the 1 'B NMR 5)-H spectrum (see Figure la); however, this is not uncommon for cases where "unique terminals" ("pseudo bridges") are present. 22 The 220-MHz NMR spectrum of B13H19 is not sufficiently resolved to enable the location of a resonance for a "unique terminal", if present, nor can a ratio of terminal to bridge hydrogens be obtained. 23 Thus with the theoretical and experimental data available, we conclude the H(9-11) probably contains appreciable terminal hydrogen character (toward B(11)), but at this time we cannot unequivocally prove this supposition.…”

“…The mass spectral analysis of the recovered 10 2 indicated that no appreciable boron exchange had taken place with the KB13H18. A 6) 198 ( 13) 15 (1) 25 (7) 3( 2) 13 (3) B( 2) 68 ( 6) 339 ( 23) 23(1) 14 (8) -6(2) 20(4) B(3) 86 ( 6) 169 ( 12) 22 (1) -9( 7) 15 (2) 2(3) B( 4)…”

Spectra and structure of phosphorus-boron compounds. 13. A multinuclear magnetic resonance study of cyclic boron-phosphorus compounds

“…Boron-11 resolution-enchanced spectra were obtained by employing previously published methods. [16][17] All chemical shifts are referenced to internal TMS. Boron-11 chemical shifts are referenced to external BFs-O^Hsh and 31P chemical shifts are referenced to external 85% H3PO4.…”

Boranes. XLVI. Nuclear magnetic resonance studies of octaborane(14) and isononaborane(15)

“…A recent nB NMR study utilizing the exponential line-narrowing technique has, however, established the 4212 topological formulation as the most likely structure for BeHiz. 2 The success of this technique in the nB NMR studies of BsHn and other boron hydrides has suggested its application to the extremely unstable hydrides BsHm and Z-B9H15. The structures of these compounds have been uncertain since early UB NMR studies suggested that they both contain six bridging hydrogens.3~5 These proposed structures fail to reconcile the expected nonbonded H-H interactions associated with placing six bridging hydrogens around the open face of a Bs or B9 cage.…”