[Mo₁₅₄(NO)₁₄O₄₂₀(OH)₂₈(H₂O)₇₀](25 ± 5)−: A Water‐Soluble Big Wheel with More than 700 Atoms and a Relative Molecular Mass of About 24000

Complex clusters the size of small proteins can be generated in reduced molybdate solutions by linking defined fragments. An example of this is the giant cluster (NH 4 ) 25±5 [Mo 154 (NO) 14 O 420 (OH) 28 (H 2 O) 70 ]·ca. 350 H 2 O with a molar mass of more than 30000 gmol −1 , the anion of which is shaped like a tire with a nanodimensional cavity more than 20 Å in diameter and has an extremely large inner and outer surface as well as a large number of mobile electrons.