Inorganic Chemistry, Vol.42, No.21, 6601-6603, 2003
A novel undecametallic iron(III) cluster with an S=11/2 spin ground state
The reaction of [NEt4](2)[Fe2OCl6] with sodium benzoate, 4,6-dimethyl-2-hydroxypyrimidine (dmhp), and 1,1,1-tris(hydroxymethyl)ethane (H(3)thme) gives the undecametallic compound [NEt4]-[Fe11O4(O2CPh)(10)(thme)(4)(dmhP)(2)Cl-4]. X-ray crystallography, EPR spectroscopy, bulk magnetic susceptibility studies, and low-temperature single-crystal magnetic measurements were used to characterize the compound. Magnetic measurements indicate an S = 11/2 ground state with the parameters g = 2.03 and D = -0.46 cm(-1). Single-crystal magnetic studies show hysteresis of molecular origin at T < 1.2 K with fast quantum mechanical tunneling at zero field.