Reactions of the elements with PrI3 in sealed Nb containers at 860-920-degrees-C yields Pr12I17Z2 for Z = Fe and Re. The new structure type was characterized for the former (P1BAR, Z = 1, a = 11.798 (4) angstrom, b = 11.791 (2) angstrom, c = 9.830 (2) angstrom, alpha = 114.87(2)degrees, beta = 104.82(4)degrees, gamma = 93.19(2)degrees, R/R(w) = 3.2/3.8% for 2967 data, 143 variables). The unusually low I:Pr ratio for a phase with isolated clusters is achieved by seven I(i-i) bridges per cluster in which iodine simultaneously bridges metal edges in two clusters. The Z-centered Pr6I12-type clusters are joined into layers by three pairs of centric I(i-i) and (I(i-a)) bridges. The layers are further joined in the third direction by a unique planar I(i-i) plus other types of iodine bridges. The 2.75-angstrom Pr-Fe bonds appear to be particularly short.