The origin of broadening of 13C(carborane) NMR signals of 1,2‐, 1,7‐ and 1,12‐dicarba‐closo‐dodecaboranes(12) and several diphenylsilyl derivatives has been examined in detail and could be traced only partially to unresolved 13C–11B spin‐spin coupling. Other contributions to the line widths arise from 13C–1H dipole‐dipole interactions and, in particular, from isotope‐induced chemical shifts 1Δ10/11B(13C), observed here for carboranes for the first time. In the case of 1‐diphenylsilyl‐1,2‐dicarba‐closo‐dodecaborane(12), the coupling constant 1J(13C,13C) = 9.3 Hz was measured in natural abundance of 13C. The small value of this coupling constant and its negative sign is predicted by calculations based on optimised structures [B3LYP/6‐311+G(d,p) level of theory] of the parent carboranes and 1‐silyl‐1,2‐dicarba‐closo‐dodecaborane(12) as a model compound [calcd. 1J(13C,13C) = –10.5 Hz]. Calculated coupling constants 1J(13C,11B) are small (<7 Hz), in contrast to published assumptions, and of either sign, whereas 1J(11B,11B) are all positive and range up to 15 Hz.
We report the covalent support of functionalized nickel complexes on magnetic core–shell hybrid particles γ‐Fe2O3/SiO2. Two completely different ways of connecting the particle with these nickel complexes were carried out. The first approach used the hydrosilylation method between the alkene‐substituted nickel complex and a silane. In a second approach, the particles were connected with the complexes by means of click chemistry (copper‐catalyzed Huisgen 1,3‐dipolar cycloaddition). For this purpose, the nickel complexes were substituted with an alkyne moiety. Transmission and scanning electron microscopies, energy‐dispersive X‐ray diffraction, and FTIR spectroscopy were the methods employed to characterize the successful heterogenization of the nickel complexes.
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