Supramolecular Mn(II) and Mn(II)/Mn(III) grid complexes with [Mn-9(mu(2)-O)(12)] core structures. Structural, magnetic, and redox properties and surface studies

Zhao L; Xu ZQ; Grove H; Milway VA; Dawe LN; Abedin TSM; Thompson LK; Kelly TL; Harvey RG; Miller DO; Weeks L; Shapter JG; Pope KJ

Inorganic Chemistry, Vol.43, No.13, 3812-3824, 2004

Zhao L, Xu ZQ, Grove H, Milway VA, Dawe LN, Abedin TSM, Thompson LK, Kelly TL, Harvey RG, Miller DO, Weeks L, Shapter JG, Pope KJ

A series of [3 x 31 Mn(11)(9), antiferromagnetically coupled, alkoxide-bridged, square grid complexes, derived from a group of "tritopic" dihydrazide ligands, is described, The outer ring of eight Mn(II) centers in the grids is isolated magnetically from the central Mn(II) ion, leading to an S = 0 ground state for the ring, and an S = 5/2 ground state overall in each case. Exchange in the Mn(11)8 ring can be represented by a 1D chain exchange model. Rich electrochemistry displayed by these systems has led to the production of Mn(II)Mn(III) mixed-oxidation-state grids by both electrochemical and chemical means. Structures are reported for [Mn-9(2poaP)(6)](C2N3)(6).1OH(2)O (1), [Mn-9(2poaP)(6)](2)Mn(NCS)(4)(H2O)](2)(NCS)(8).10H(2)O (2), [Mn-9(2poapz)(6)](NO3)(6).14.5H(2)O (3), [Mn-9(2popp)(6)](NO3)(6).12H(2)O (4), [Mn-9(2pomp)(6)](MnCl4)(2)Cl-2.2CH(3)OH.7H(2)O (5), and [Mn-9(Cl2poap)(6)](ClO4)(9).7H(2)O (6). Compound 1 crystallized in the tetragonal system, space group P4(2)/n, with a = 21.568(l) Angstrom, c = 16.275(1) Angstrom, and Z = 2. Compound 2 crystallized in the triclinic system, space group P (1) over bar, with a = 25.043(l) Angstrom, b = 27.413(l) Angstrom, c = 27.538(2) Angstrom, alpha = 91.586(2)degrees, beta = 113.9200(9)degrees, gamma = 111,9470(8)degrees, and Z = 2. Compound 3 crystallized in the triclinic system, space group P (1) over bar, with a = 18.1578(12) Angstrom, b = 18.2887(12) Angstrom, c = 26.764(2) Angstrom, alpha = 105.7880(12)degrees, beta = 101.547(2)degrees, gamma = 91,1250(11)degrees, and Z = 2. Compound 4 crystallized in the tetragonal system, space group P4(1)2(1)2, with a = 20.279(l) Angstrom, c = 54.873(6) Angstrom, and Z = 4. Compound 5 crystallized in the tetragonal system, space group (14) over barA, with a = 18.2700(2) Angstrom, c = 26.753(2) Angstrom, and Z = 2. Compound 6 crystallized in the triclinic system, space group P (1) over bar, with a = 19.044(2) Angstrom, b = 19.457(2) Angstrom, c = 23.978(3) Angstrom, alpha = 84.518(3)degrees, beta = 81.227(3)degrees, gamma = 60.954(2)degrees, and Z= 2. Preliminary surface studies on Au(111), with a Mn(II) grid complex derived from a sulfur-derivatized ligand, indicate monolayer coverage via gold-sulfur interactions, and the potential for information storage at high-density levels.