FLUCTUATION OF BE2+ BETWEEN 4 N-OXIDE ACCEPTORS AND THE POLARIZABILITY CAUSED BY THE BE2+ MOTION

We studied 0.2 mol dm-3 acetonitrile solutions of 1:1 Be(AuCl4)2 complexes of cis-1,2-bis-(2-naphthiridine di-N-oxide) ethylene and 1:2 Be(AuCl4)2 complexes of 1,2-bis-(dimethylaminomethyl N-oxide) benzene by FTIR spectroscopy. One Be2+ ion interacts with four O-atoms of the N-oxide groups as indicated by complete vanishing of the nu(NO) bands. Intense continua indicate that the Be2+ ions fluctuate between these four acceptor groups in a four-minima Be2+ potential with relatively steep slopes at the acceptor groups. The Be2+ ions can relatively easily be shifted within these complexes. They show large "Be2+ polarizability".