Ligands electropositive

Spiro-oxyphosphoranes (101), with the highly electropositive ligand hydrogen have been made from the reaction of trialkyl phosphites (or of riaminophosphines) with glycols.122... 

The Mutterties rule which states that the more electronegative ligands occupy the axial position, while electropositive ligands must be at the equatorial position lone pair electrons should be located at the equatorial position. 

We conclude that a core which has both electron pairs and holes can be polarized by electronegative and electropositive ligands, with the former "opening holes"... 

The more electropositive ligands tend to occupy equatorial positions, while the more electronegative ligands tend to occupy apical positions. 

---