The fluorine has a lone pair, and the oxygen has a lone pair. Both are donate-able, so they should both act as ligands. I know fluorine is more electronegative, but oxygen is quite electronegative itself, so the reason must lie somewhere else.

  • $\begingroup$ Can (...) not behave? Could you correct your grammar to clarify? $\endgroup$ – Mithoron May 13 '17 at 22:55
  • $\begingroup$ Also they both can coordinate. $\endgroup$ – Mithoron May 13 '17 at 22:56
  • $\begingroup$ How in the world could $\ce{BF3}$ act as a ligand? Its the opposite of a Lewis base, a Lewis acid for that matter. $\endgroup$ – Pritt says Reinstate Monica May 14 '17 at 3:12
  • $\begingroup$ @Mithoron The definition of a ligand given to us is 'a species which tends to form dative bonds with transition metal ions', which is an L-type ligand ( I literally just read this off wikipedia, so not sure ). Can they both act as L-type ligands? The official answer disagrees. $\endgroup$ – Saad May 14 '17 at 8:47
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    $\begingroup$ Not bad searching @PrittBalagopal If BF3 coordinates to metal center accepting electrons it is also a ligand but "Z-type". $\endgroup$ – Mithoron May 14 '17 at 17:11