The reaction of Fe(ClO4)(2)center dot 6H(2)O with t-BuPO3H2 or Cl3CPO3H2 in the presence of an ancillary pyrazole phenolate as a coligand, H(2)phpzH=[H(2)phpzH = 3(5)-(2-hydroxyphenyl)pyrazole], afforded tetra- and pentanuclear Fe(III) phosphonate complexes [Fe-4(t-BuPO3)(4)(HphpzH)(4)]center dot 5CH(3)CN center dot 5CH(2)Cl(2) (1) and [HNEt3](2)[Fe-5(mu(3)-O)(mu-OH)(2) (Cl3CPO3)(3)(HphpzH)(5)(mu-phpzH]center dot 3CH(3)CN center dot 2H(2)O (2). Single-crystal X-ray structural analysis reveals that 1 possesses a cubic double-4-ring (D4R) core similar to what is found in zeolites. The molecular structure of 2 reveals it to be pentanuclear. It crystallizes in the chiral PI space group. Magnetic on 1 and 2 have also been carried out, which reveal that the bridging phosphonate ligands mediate weak antiferromagnetic interactions between the Fe(III) ions. Magnetization dynamics of 1 and 2 have been corroborated by a Mossbauer spectroscopy analysis.