The syntheses of the aliphatic tripodal tetramine ligands N(CH2CH2CH2NH2)(3) (1), N[(CH2CH2CH2NH2)(2)(CH2CH2NH2)] (2), and N[(CH2CH2CH2NH2)(CH2CH2NH2)(2)] (3) are reported. The tripodal N-4-ligands 1-3 react with Cu(OH)(2) in water to give blue copper(II) complexes. Addition of NH4PF6 to such solutions yields complexes of the type [Cu(N-4)(NH3](PF6)(2) [4; N-4 = 1, 4a; N-4 = 2, 4b; N-4 = 3, 4c]. The molecular structures of complexes 4a-c have been determined by X-ray diffraction, All three complexes can be crystallized from water. Selected crystallographic details are as follows 4a [4b] (4c) : formula C9H27CuF12N5P2 [C8H25CuF12N5P2] {C7H23 CuF12N5P2}, M = 558.82 [544.79] {530.76} amu, monoclinic [monoclinic] {orthorhombic}, P2(1)/c [C2/c] {P2(1)2(1)2}, 8.9519(14) [30.181(6)] {15.075(5)} Angstrom, b = 16.803(3) [8.914(3)] {12.2939(14)} Angstrom, c = 13.834(2) [14.253(4)] {10.064(2)} Angstrom, alpha = 90.0 [90.0] {90.0}degrees, beta = 94.183(12) [93.76(2)] {90.0}degrees, gamma = 90.0 [90.0] {90.0}degrees, V = 2075.3(10) [3826(3)] {1865.2(12)} Angstrom(3), Z = 4 [8] {4}, R = 5.10 [3.42] {4.32}%, R(w) = 6.67 [5.12] {5.23}% for 2480 [2137] {1533} absorption corrected structure factors F-o(2) greater than or equal to 3 sigma(F-o(2)) and 262 [255] {245} refined parameters. The complex dications in 4a-c exhibit a trigonal-bipyramidal geometry with the tertiary nitrogen of the tripodal Ligand and the ammonia nitrogen in the axial positions. Complexes with the unsymmetric ligands 2 and 3 possess both five and six membered chelate rings. Depending on the ligand, the size of the cavity for the ammonia ligand increases from 4a to 4c. This leads to a shortening of the Cu-NH3 bond length with the shortest bond of this type observed for 4c.