Syntheses of SnZr(OR)(6) (R = Pr-i, (t)Bu) and PbZr(O(t)Bu)(6) are described. With Pb and the smaller ligand (OPr)-Pr-i, no 1:1 compound forms, but instead Pb4Zr2((OPr)-Pr-i)(16) and Pb2Zr4((OPr)-Pr-i)(20) are isolated. The latter two compounds are shown to have serpentine (not close) structures with six-coordinate Zr and three- and four-coordinate Pb. Spectroscopic studies show fluxionality (including Pb site exchange) and retention of structure in aromatic solvents. Synthetic interconversions are effected with addition of the appropriate alkoxide (Pb((OPr)-Pr-i)(2) or Zr((OPr)-Pr-i)4) with the correct stoichiometry. Titanium forms no analogous compounds. Crystallographic data (both P2(1)/c at -174 degrees C) for Pb4Zr2((OPr)-Pr-i)(16), a = 12.190(6) Angstrom, b = 14.701(7) Angstrom, c = 19.978(13) Angstrom, and beta = 105.57(3)degrees with Z = 2; for Pb2Zr4((OPr)-Pr-i)(20), a = 16.996(6) Angstrom, b = 10.014(3) Angstrom, c = 24.924(9) Angstrom, and beta = 105.86(1)degrees with Z = 2.