The syntheses and structural details of tetraisopropoxyaluminates and tetra-tert-butoxyaluminates of nickel(II), copper-(I), and copper(II) are reported. Within the nickel series, either Ni[Al((OPr)-Pr-i)(4)](2)center dot 2HO(i)Pr, with nickel(II) in a distorted octahedral oxygen environment, or Ni[Al((OPr)-Pr-i)(4)](2)center dot py, with nickel(II) in a square-pyramidal O4N coordination sphere, or Ni[((PrO)-Pr-i)((BUO)-B-t)(3)Al](2), with Ni(II) in a quasi-tetrahedral oxygen coordination, has been obtained. Another isolated complex is Ni[((PrO)-Pr-i)(3)AlOAl((OPr)-Pr-i)(3)]center dot 3py (with nickel(II) being sixfold-coordinated), which may also be described as a "NiO" species trapped by two Al((OPr)-Pr-i)(3) Lewis acid-base systems stabilized at nickel by three pyridine donors. Copper(l) compounds have been isolated in three forms: [((PrO)-Pr-i)(4)Al]Cu center dot 2py, [((BUO)-B-t)(4)Al]Cu center dot 2py, and CU2[((BuO)-Bu-t)(4)Al](2), In all of these compounds, the aluminate moiety behaves as a bidentate unit, creating a tetrahedrally distorted N2O2 copper environment in the pyridine adducts. In the base-free copper(I) tert-butoxyaluminate, a dicopper dumbbell [Cu-Cu 2.687(1) angstrom] is present with two oxygen contacts on each of the copper atoms. Copper(II) alkoxyaluminates have been characterized either as Cu[((BuO)-Bu-t)(4)Al](2), {Cu((PrO)-Pr-i)[((PrO)-Pr-i)4(A)l]}(2), and Cu[((BuO)-Bu-t)(3)((PrO)-Pr-i)Al](2) (copper being tetracoordinated by oxygen) or as [((PrO)-Pr-i)(4)Al](2)Cu center dot py (pentacoordinated copper similar to the nickel derivative). Finally, a copper(II) hydroxyaluminate has been isolated, displaying pentacoordinate copper (O4N coordination sphere) by dimerization, with the formula {[((BuO)-Bu-t)(4)Al]Cu(OH)center dot py}(2). The formation of all of these isolated products is not always straightforward because some of these compounds in solution are subject to decomposition or are involved in equilibria. Besides NMR [copper(I) compounds], UV absorptions and magnetic moments are used to characterize the compounds.