H-1 AND B-11 NMR OF MONO-, BIS- AND TRISC YCLOPENTADIENYLURANIUMBOROHYDRIDES - A CORRELATION BETWEEN CHEMICAL-SHIFT AND ELECTRONIC DENSITY AROUND URANIUM

H-1 and B-11 NMR of mono-, bis- and triscyclopentadienyluraniumborohyd rides. A correlation between chemical shift and electronic density aro und uranium. In the same sample in a pyrex NMR tube, it is possible to record both H-1 and B-11 NMR spectra; simple data processing removes the broad B-11 pyrex signal. A correlation between the electronic dens ity around the uranium atom, which depends on the electronic effects o f the ring substituents, and the chemical shifts of the nuclei directl y bound to the paramagnetic center is established for mono-, bis-arid triscyclopentadienyluranium borohydride complexes.