# Why can the anion NO3- behave as a L-type ligand while BF3 can not? [closed]

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.

• Can (...) not behave? Could you correct your grammar to clarify? – Mithoron May 13 '17 at 22:55
• Also they both can coordinate. – Mithoron May 13 '17 at 22:56
• How in the world could $\ce{BF3}$ act as a ligand? Its the opposite of a Lewis base, a Lewis acid for that matter. – Pritt says Reinstate Monica May 14 '17 at 3:12
• @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. – Saad May 14 '17 at 8:47
• Not bad searching @PrittBalagopal If BF3 coordinates to metal center accepting electrons it is also a ligand but "Z-type". – Mithoron May 14 '17 at 17:11