Block Inner Transition Metals Lanthanoids and Actinoids

4 f Block Inner Transition Metals (Lanthanoids and Actinoids) 

However, it is not entirely time to despair, since at least one family of metals show a remarkable consistency in their chemistry. This occurs in the oft-ignored f block of the 

High coordination numbers are common in the f block. The didentate chelate ligand 2,4-dioxopentan-3-ido (acac ) forms six-coordinate octahedral complexes with first-row d-block metal ions (like Cr(III), shown at left), but eight or nine coordinate complexes with f-block lanthanide ions (like Eu(III), shown at right). 

---