The solvent-free Yb(II) 'ate' complex 2-Yb (Figure and Table ) is a 1D coordination polymer in the solid state that is held together by electrostatic interactions between Yb and K cations, and Pʹʹ anions. The structure can be viewed as a block copolymer with alternating {KYb(Pʹʹ)3} and {K2(Pʹʹ)2} units, or alternatively as {K2Yb(Pʹʹ)4} fragments bridged by {K(Pʹʹ)}. ). The solid-state structures of 1-Ln do not appear to be fully maintained in d6benzene solutions, with three broad signals observed in the H NMR spectra of each complex due to a combination of paramagnetic broadening and dynamic aggregation processes. These resonances did not give reliable integrations for silyl groups or the α-and β-H of THF and so these spectra could not be interpreted; similarly, no signals arising from 1-Ln could be assigned in their C{ 1 H}, Si DEPT90 and 31 P{ 1 H} NMR spectra.