Inorganic Chemistry 2001-01-01

Synthesis and Characterization of a Series of Edge-Sharing Octahedral-Tetrahedral-Octahedral Linear Trinuclear Complexes [M(3)(L1O)(4)](2+), Where M = Mn(2+), Co(2+), Ni(2+), Cu(2+), and Zn(2+) and L1OH Is the Heteroscorpionate Ligand (2-Hydroxyphenyl)bis(pyrazolyl)methane.

TimothyC. Higgs, K. Spartalian, CharlesJ. O'Connor, BertholdF. Matzanke, CarlJ. Carrano

Index: Inorg. Chem. 37 , 2263, (1998)

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Abstract

The mixed functionality pyrazole/phenol ligand (2-hydroxyphenyl)bis(pyrazolyl)methane, L1OH, has been used to prepare a series of linear trimetallic systems with the general structural motif [M(3)(L1O)(4)](2+), where M = Mn(2+), Co(2+), Ni(2+), Cu(2+), and Zn(2+). Each of these complexes has been structurally characterized by X-ray crystallography giving the following structural parameters: [Zn(3)(L1O)(4)][BF(4)](2).H(2)O, C(52)H(44)N(16)B(2)F(8)O(5)Zn(3), monoclinic, a = 18.572(4) _, b = 22.400(5) _, c = 15.921(3), beta = 112.439(8) degrees, space group C2/c, Z = 4; [Cu(3)(L1O)(4)] [BF(4)](2).2MeCN, C(56)H(44)N(18)B(2)Cu(3)F(8)O(4), monoclinic, a = 40.574(2) _, b = 16.701(1) _, c = 19.841(2) _, beta = 111.388(5) degrees, space group C2/c, Z = 8; [Ni(3)(L1O)(4)][ClO(4)](2).MeCN.0.5H(2)O, C(54)H(44)N(17)Cl(2)Ni(3)O(12.5), monoclinic, a = 12.324(4) _, b = 26.537(2) _, c = 18.829(3) _, beta = 102.78(1) degrees, space group C2/c, Z = 4; [Co(3)(L1O)(4)][BF(4)](2).MeCN, C(54)H(44)N(17)B(2)Co(3)F(8)O(4), monoclinic, a = 12.395(2) _, b = 26.483(3) _, c = 18.703(4) _, beta = 103.22(2) degrees, space group C2/c, Z = 4; [Mn(3)(L1O)(4)(MeCN)][ClO(4)](2).1.4MeCN, C(56.68)H(44)N(18.34)Cl(2)Mn(3)O(12), orthorhombic, a = 15.471(2) _, b = 17.364(2) _, c = 24.216(2) _, space group Pbcn, Z = 4. For Zn(2+), Cu(2+), Ni(2+), and Co(2+) the central metal atom of the linear trimetallic [M(3)(L1O)(4)](2+) unit is four coordinate and has a pseudotetrahedral geometry with a dihedral angle, omega, between the two M(central)O(2)M(terminal) planes of 79.9 degrees (Zn), 61.2 degrees (Co), 60.4 degrees (Ni), and 46.8 degrees (Cu). The central Mn(2+) atom of [Mn(3)(L1O)(4)(MeCN)][ClO(4)](2).1.4MeCN is five-coordinate, with a trigonal bipyramidal stereochemistry, the result of an equatorially coordinated MeCN solvent molecule. Variable-temperature magnetic data indicate that the Ni, Cu, and Mn complexes display modest antiferromagnetic coupling between the metal centers, while the Co derivative is strongly ferromagnetically coupled.