A novel dimanganese complex linked by an unusually strong hydrogen bond. X-ray structure of the hydrogen-bonded complex and ab initio calculations

In an attempt to prepare the fluoro complex (CO)(3)(dppe)MnF (3) by treating a CH(2)Cl(2) solution of the aqua complex [(CO)(3)(dppe)Mn(OH(2))]BF(4) (1) with NaF((aq)), we isolated instead, the dimanganese complex, [(CO)(3)(dppe)Mn(OH(2))(...)FMn(dppe)(CO)(3)]BF(4) (2). The two moieties, 1 and 3, are held together by an unusually strong O-H(...)F hydrogen bond (O(...)F = 2.458(3) Angstrom, H(...)F = 1.52 Angstrom) between the aqua ligand on one manganese and the fluoro atom on the other manganese. Using as a simple model the interaction between (+)Li(H(2)O) and FLi, the hydrogen bonding distance O-H(...)F was calculated to be; O(...)F = 2.443 Angstrom. Authentic 3 was prepared in a homogeneous system using CH(2)Cl(2)-soluble [Et(4)N]F. (C) 2001 Elsevier Science B.V. All rights reserved.