(iv) Prefixes mono, di, tri, etc , are used to indicate the number of the
individual ligands in the coordination entity When the names of
the ligands include a numerical prefix, then the terms, bis, tris,
tetrakis are used, the ligand to which they refer being placed in
parentheses For example, [NiCl2(PPh3)2] is named as
dichloridobis(triphenylphosphine)nickel(II)