Self-Assembled Supramolecular M9 (Mn(II), Fe(III), Zn(II)), M5 (Fe(III)), and [M3]2 (Pb(II)) Complexes: Structural, Magnetic, and Mössbauer Properties

The tritopic ligand 2poap self-assembles in the presence of Zn(NO 3 ) 2 and Fe(NO 3 ) 3 to form homoleptic [3 x 3] nonanuclear M 9 (M = Zn(II), Fe(III)) square grid structures and with Pb(ClO 4 ) 2 to form a dimerized lineartrinuclear [Pb 3 ] 2 structure. Cl2poap and Cl2poapz form self-assembled homoleptic [3 x 3] Mn(II) 9 square grids with Mn(ClO 4 ) 2 and Mn(NO 3 ) 2 , respectively, but an unusual incompletely metalated Fe(III) 5 square grid is formed on reaction of Cl2poap with Fe(ClO 4 ) 3 . X-ray structures are reported for [Mn 9 (Cl2poap-2H) 6 ](ClO 4 ) 6 .10H 2 O (3), [Mn 9 (Cl2poapz-2H) 6 ] (NO 3 ) 6 .22H 2 O (4), [Zn 9 (2poap-2H) 3 (2poap-H) 3 ](NO 3 ) 9 .24H 2 O (5), [Pb 3 (2poap-2H) (ClO 4 ) 4 ] 2 .8H 2 O (6), and [Fe 5 -(Cl2poap-H) 6 ](ClO 4 ) 9 .34.5H 2 O (7). Compound 3 crystallized in the monoclinic system, space group P1, with a = 18.179(1) A, b = 18.857(1) A, c = 25.871(2) A, α = 70.506(2)°, β = 86.440(1)°, y = 75.175(2)°, and z = 2. Compound 4 crystallized in the monoclinic system, space group P1, with a = 16.900(2) A, b = 20.02393) A, c = 25.663() A, α = 84.743(3)°, β = 84.885(2)°, y = 67.081(2)°, and z = 2. Compound 5 crystallized in the monoclinic system, space group P1, with a = 18.482(1) A, b = 18.774(1) A, c = 28.112(2) A, a = 104.020(1)°, β = 97.791(1)°, γ = I17.036(1)°, and z = 2. Compound 6 crystallized in the monoclinic system, space group P1, with a = 10.0513(6) A, b = 11.0958(6) A, c = 17.334(1) A, α = 100.932(1)°, β = 100.387(1)°, γ = 94.565(1)°, and z = 2. Compound 7 crystallized in the monoclinic system, space group P1, with a = 19.164(1) A, b = 19.587(2) A, c = 26.673(2) A, a = 76.430(2)°, β = 78.834(2)°, y = 64.973(1)°, and z = 2. Compound 3 exhibits intramolecular antiferromagnetic exchange within the nonanuclear [Mn 9 (μ-O) 1 2 ] grid structure (J = -4.6 cm - 1 ), while the analogous nonanuclear complex [Fe 9 (2poap-2H) 6 ](NO 3 ) 1 5 .18H 2 0 (8) is dominated by intramolecular antiferromagnetic coupling at high temperatures but exhibits a low-temperature feature indicative of additional ferromagnetic interactions. The isolated pentanuclear Fe 5 [4 + 1] square grid in 7, with distant Fe-Fe bridging, exhibits very weak antiferromagnetic coupling (J = -0.2 cm - 1 ). Mossbauer spectroscopy data are consistent with high-spin Fe(III) 9 and Fe(III) 5 structures.