Spin-state-selective excitation in gradient-selected heteronuclear cross-polarization NMR experiments

Synthesis and Characterization of Spirosilanes – 1,2‐Hydroboration and 1,1‐Carboboration

“…Contour plot of (part of the aliphatic region) the 2D 1 H- 13 C correlated spectrum of spirosilane 3a [recorded by the gradientselected heteronuclear single quantum coherence (gs)HSQC method]. [27] a heteroaryl group (1c), and a potentially coordinating Lewis base (1d).…”

Synthesis, Characterization and Reactivity of Dinuclear and Trinuclear Aluminum‐Bridged Ferrocenophanes

“…The formation of 4 is the result of complex rearrangements in the equilibrated mixtures in order to reduce electron deficiency and coordinative unsaturation of the aluminum atoms. The presence of slow dynamic equilib- Table 1. 13 C NMR spectroscopic data [a,b, [a] The assignment of the NMR signals is based on 1 H{ 1 H} NOESY [9] and 2D 1 H-13 C gHSQC [10] ria is illustrated in Figure 1 by 1 H-1 H NOE difference spectra, which, in addition to NOE, also give rise to numerous intensities caused by inter-and intramolecular exchange processes. In contrast, as shown in Figure 2, for pure compound 4b (isolated and redissolved crystalline sample), the analogous experiments reveal solely intramolecular exchange between the AlEt(a,b) groups.…”

“…[a] The assignment of the NMR signals is based on 1 H{ 1 H} NOESY [9] and 2D 1 H-13 C gHSQC [10] must be considered as intermediates prior to the formation of 4. Schemes 2, 4 and 5 emphasize the complex behaviour of 1,1Ј-aluminum-substituted ferrocene derivatives.…”

Fused Silacarbacycles Containing a Silole Unit: 1,2‐Hydroboration and 1,1‐Organoboration of Alkynyl(vinyl)silanes

“…The synthesis of the alkynylsilanes 1-5 is described elsewhere. [15] [26] and in some cases by gradient-enhanced 1 H-1 H NOE difference experiments. [27] EI-MS spectra: Finnigan MAT 8500 spectrometer (ionisation energy 70 eV) with direct inlet, the m/z data refer to the isotopes 1 H, 12 C, 11 B, 14 N, 28 Si.…”