HEXANUCLEAR AND DODECANUCLEAR MACROCYCLIC COPPER(II) AND NICKEL(II) COMPLEXES WITH ALMOST PLANAR BENZENE-LIKE METAL ARRAYS

Template condensation of 2,6-diformyl-4-(R)phenol (R = methyl, tert-bu tyl) with 1,3-diamino-2-hydroxypropane in the presence of copper(lI) a nd nickel(II) salts and base results in the formation of novel hexacop per(II) and hexanickel(II) complexes of the 30-membered, 3:3 macrocycl ic ligands (H(6)MME, H(6)MTB). The macrocyclic rings contain pseudohex agonal ''benzene-like'' arrangements of metal centers, which are linke d by alternating double (mu(2)-phenoxide, mu(2)-hydroxide) and single (mu(2)-alkoxide) bridges within each ring: [Cu-6(L)(mu(2)-OH)(3)](2)X( 6) . yH(2)O (L = MME: X = NO3, y = 10 (1); X = ClO4, y = 6 (2); X = BF 4, y = 8 (3). L = MTB: X = ClO4, y = 8 (4); X = BF4, y = 14 (5)), [Ni- 6(MME)(mu(2)-OH)(3)(H2O)(6)](2)X(6) . yH(2)O (X = ClO4, y = 4 (7); X = NO3, y = 16 (8)). Two complexes (1 and 4) are dimers, with the hexago nal fragments linked by axial interactions, forming dodecanuclear spec ies. 1 crystallized in the triclinic system, space group P ($) over ba r 1, with a = 14.482(7) Angstrom, b = 14.72(1) Angstrom, c = 12.193(4) Angstrom, alpha = 95.64(5)degrees, beta = 92.32(4)degrees, gamma = 11 4.85(4)degrees, and Z = 2 (R = 0.103, R(w) = 0.077). Addition of NCS t o the mother liquor from the preparation of 4 led to the formation of a 2:2 macrocyclic complex [Cu(H(2)MTB)(NCS)(2)](n) (6). 6 crystallized in the monoclinic system, space group P2(1)/c, with a = 12.207(2) Ang strom, b = 14.254(3) Angstrom, c = 9.550(3) Angstrom, beta = 95.42(2)d egrees, and Z = 2 (R = 0.041, R(w) = 0.035). The magnetic susceptibili ties of 1, 2, 4, 6, 7, and 8 were measured in the temperature range 4- 305 K. The data for 1, 2, and 4 were analyzed and reproduced by using appropriate six-spin and twelve-spin models. For the copper derivative s, the presence of intra-ring and inter-ring antiferromagnetic interac tions was determined with -2J(1) = -2J(2) = 318.4 cm(-1) (1), -2J(1) = -2J(2) = 485.2 cm(-1) (2), and -2J(1) = -2J(2) = 598.8 cm(-1) (4) (si x-spin model) and with -2J(1) = 303.8 cm(-1), -2J(2) = 262.8 cm(-1), - 2J(3) = 20.0 cm(-1) (1), -2J(1) = 484.5 cm(-1), -2J(2) = 479.0 cm(-1), -2J(3) = 16.4 cm(-1) (2), and -2J(1) = 494.2 cm(-1), -2J(2) = 412.8 c m(-1), -2J(3) = 16.4 cm(-1) (4) (twelve-spin model), while for the nic kel complexes the presence of alternating ferro- and antiferromagnetic coupling was established using a sixspin model.