Milway Victoria A, Niel Virginie, Abedin Tareque S M, Xu Zhiqiang, Thompson Laurence K, Grove Hilde, Miller David O, Parsons Stewart R
Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X7, Canada.
Inorg Chem. 2004 Mar 22;43(6):1874-84. doi: 10.1021/ic030113u.
The structures and magnetic properties of self-assembled copper(II) clusters and grids with the "tritopic" ligands 2poap (a), Cl2poap (b), m2poap (c), Cl2pomp (d), and 2pomp (e) are described [ligands derived by reaction of 4-R-2,6-pyridinedicarboxylic hydrazide (R = H, Cl, MeO) with 2-pyridinemethylimidate (a-c, respectively) or 2-acetylpyridine (d, R = Cl; e, R = H)]. Cl2poap and Cl2pomp self-assemble with Cu(NO(3))(2) to form octanuclear "pinwheel" cluster complexes [Cu(8)(Cl2poap-2H)(4)(NO(3))(8)].20H(2)O (1) and [Cu(8)(Cl2pomp-2H)(4)(NO(3))(8)].15H(2)O (2), built on a square [2 x 2] grid with four pendant copper arms, using "mild" reaction conditions. Similar reactions of Cl2pomp and 2pomp with Cu(ClO(4))(2) produce pinwheel clusters Cu(8)(Cl2pomp-2H)(4)(H(2)O)(8)(8).7H(2)O (3) and Cu(8)(2pomp-2H)(4)(H(2)O)(8)(8) (4), respectively. Heating a solution of 1 in MeOH/H(2)O produces a [3 x 3] nonanuclear square grid complex, Cu(9)(Cl2poap-H)(3)(Cl2poap-2H)(3)(9).18H(2)O (5), which is also produced by direct reaction of the ligand and metal salt under similar conditions. Reaction of m2poap with Cu(NO(3))(2) produces only the [3 x 3] grid Cu(9)(m2poap-H)(2)(m2poap-2H)(4)(8).17H(2)O (6) under similar conditions. Mixing the tritopic ligand 2poap with pyridine-2,6-dicarboxylic acid (picd) in the presence of Cu(NO(3))(2) produces a remarkable mixed ligand, nonanuclear grid complex Cu(9)(2poap-H)(4)(picd-H)(3)(picd-2H)(9).9H(2)O (7), in which aromatic pi-stacking interactions are important in stabilizing the structure. Complexes 1-3 and 5-7 involve single oxygen atom (alkoxide) bridging connections between adjacent copper centers, while complex 4 has an unprecedented mixed micro-(N-N) and micro-O metal ion connectivity. Compound 1 (C(76)H(92)N(44)Cu(8)O(50)Cl(4)) crystallizes in the tetragonal system, space group I, with a = 21.645(1) A, c = 12.950(1) A, and Z = 2. Compound 2 (C(84)H(88)N(36)O(44)Cl(4)Cu(8)) crystallizes in the tetragonal system, space group I, with a = 21.2562(8) A, c = 12.7583(9) A, and Z = 2. Compound 4 (C(84)H(120)N(28)O(66)Cl(8)Cu(8)) crystallizes in the tetragonal system, space group I4(1)/a, with a = 20.7790(4) A, c = 32.561(1) A, and Z = 4. Compound 7(C(104)H(104)N(46)O(56)Cu(9)) crystallizes in the triclinic system, space group P, with a = 15.473(1) A, b = 19.869(2) A, c = 23.083(2) A, alpha = 88.890(2) degrees, beta = 81.511(2) degrees, gamma = 68.607(1) degrees, and Z = 2. All complexes exhibit dominant intramolecular ferromagnetic exchange coupling, resulting from an orthogonal bridging arrangement within each polynuclear structure.
描述了具有“三齿”配体2poap(a)、Cl2poap(b)、m2poap(c)、Cl2pomp(d)和2pomp(e)的自组装铜(II)簇和网格的结构及磁性性质[这些配体是通过4 - R - 2,6 - 吡啶二甲酰肼(R = H、Cl、MeO)分别与2 - 吡啶甲基亚氨酸酯(a - c)或2 - 乙酰吡啶(d,R = Cl;e,R = H)反应得到的]。Cl2poap和Cl2pomp与Cu(NO(3))(2)自组装形成八核“风车”簇配合物[Cu(8)(Cl2poap - 2H)(4)(NO(3))(8)].20H(2)O(1)和[Cu(8)(Cl2pomp - 2H)(4)(NO(3))(8)].15H(2)O(2),它们基于具有四个悬垂铜臂的方形[2×2]网格构建,采用“温和”反应条件。Cl2pomp和2pomp与Cu(ClO(4))(2)的类似反应分别生成风车簇Cu(8)(Cl2pomp - 2H)(4)(H(2)O)(8)(8).7H(2)O(3)和Cu(8)(2pomp - 2H)(4)(H(2)O)(8)(8)(4)。在甲醇/水混合溶液中加热1的溶液会生成[3×3]九核方形网格配合物Cu(9)(Cl2poap - H)(3)(Cl2poap - 2H)(3)(9).18H(2)O(5),在类似条件下配体与金属盐直接反应也可生成该配合物。在类似条件下,m2poap与Cu(NO(3))(2)反应仅生成[3×3]网格Cu(9)(m2poap - H)(2)(m2poap - 2H)(4)(8).17H(2)O(6)。在Cu(NO(3))(2)存在下,将三齿配体2poap与吡啶 - 2,6 - 二甲酸(picd)混合会生成一种显著的混合配体九核网格配合物Cu(9)(2poap - H)(4)(picd - H)(3)(picd - 2H)(9).9H(2)O(7),其中芳香π - 堆积相互作用对稳定结构很重要。配合物1 - 3和5 - 7在相邻铜中心之间涉及单氧原子(醇盐)桥连连接,而配合物4具有前所未有的混合微观(N - N)和微观 - O金属离子连接性。化合物1(C(76)H(92)N(44)Cu(8)O(50)Cl(4))在四方晶系,空间群I中结晶,a = 21.645(1) Å,c = 12.950(1) Å,Z = 2。化合物2(C(84)H(88)N(36)O(44)Cl(4)Cu(8))在四方晶系,空间群I中结晶,a = 21.2562(8) Å,c = 12.7583(9) Å,Z = 2。化合物4(C(84)H(120)N(28)O(66)Cl(8)Cu(8))在四方晶系,空间群I4(1)/a中结晶,a = 20.7790(4) Å,c = 32.561(1) Å,Z = 4。化合物7(C(104)H(104)N(46)O(56)Cu(9))在三斜晶系,空间群P中结晶,a = 15.473(1) Å,b = 19.869(2) Å,c = 23.083(2) Å,α = 88.890(2)°,β = 81.511(2)°,γ = 68.607(1)°,Z = 2。所有配合物都表现出主要的分子内铁磁交换耦合,这是由每个多核结构内的正交桥连排列导致的。