Are there positively charged ligands which can bind to a central metal atom to form coordination compounds?
I know that ligands are Lewis bases which donate a pair of electrons, and the central metal atom is usually a Lewis acid.
However, a positive charge on a species usually means it is electron-deficient. In that case, there would be no suitable electrons for it to bond to the central metal atom. So, even if positively charged ligands do exist, I think there would be very few. In such cases, it might bond with central atom which is electron rich forming the coordinate bond in the opposite way. Is that possible?