f-block-element-f-block-element NMR spin-spin coupling

This is a report on the synthesis and structure of novel dinuclear Yb-II complexes. In one of the described compounds, the two Ybn(II) centres are in close proximity and chemically different. Thus, an f-block-element-f-block-element coupling pattern was observed. The low-field Yb-171 signal consists of a central singlet and two satellites with integral intensities of about 7 % each. This 14 % approximately corresponds to the natural abundance of the 17 Yb-171 isotope and was assigned as a doublet arising from (1)J(Yb-171, Yb-171) spin-spin coupling with a magnitude of 76.1 Hz. Furthermore, the relevance of such studies in understanding dimer equilibria and the rearrangement chemistry of rather bulky structural ensembles is discussed.