Synthetic, structural, spectroscopic and theoretical study of a Mn(III)-Cu(II) dimer containing a Jahn-Teller compressed Mn ion

TY - JOUR

T1 - Synthetic, structural, spectroscopic and theoretical study of a Mn(III)-Cu(II) dimer containing a Jahn-Teller compressed Mn ion

AU - Berg, Nelly

AU - Hooper, Thomas N.

AU - Liu, Junjie

AU - Beedle, Christopher C.

AU - Singh, Saurabh Kumar

AU - Rajaraman, Gopalan

AU - Piligkos, Stergios

AU - Hill, Stephen

AU - Brechin, Euan K.

AU - Jones, Leigh F.

PY - 2013/1/7

Y1 - 2013/1/7

N2 - The heterobimetallic complex [Cu(II)Mn(III)(L)(2)(py)(4)](ClO(4))·EtOH (1) built using the pro-ligand 2,2'-biphenol (LH(2)), contains a rare example of a Jahn-Teller compressed Mn(III) centre. Dc magnetic susceptibility measurements on 1 reveal a strong antiferromagnetic exchange between the Cu(II) and Mn(III) ions mediated through the phenolate O-atoms (J = -33.4 cm(-1)), with magnetisation measurements at low temperatures and high fields suggesting significant anisotropy. Simulations of high-field and high frequency powder EPR data suggest a single-ion anisotropy D(Mn(III)) = +4.45 cm(-1). DFT calculations also yield an antiferromagnetic exchange for 1, though the magnitude is overestimated (J(DFT) = -71 cm(-1)). Calculations reveal that the antiferromagnetic interaction essentially stems from the Mn(d(x(2)-y(2)))-Cu(d(x(2)-y(2))) interaction. The computed single-ion anisotropy and cluster anisotropy also correlates well with experiment. A larger cluster anisotropy for the S = 3/2 state compared to the single-ion anisotropy of Mn(III) is rationalised on the basis of orbital mixing and various contributions that arise due to the spin-orbit interaction.

AB - The heterobimetallic complex [Cu(II)Mn(III)(L)(2)(py)(4)](ClO(4))·EtOH (1) built using the pro-ligand 2,2'-biphenol (LH(2)), contains a rare example of a Jahn-Teller compressed Mn(III) centre. Dc magnetic susceptibility measurements on 1 reveal a strong antiferromagnetic exchange between the Cu(II) and Mn(III) ions mediated through the phenolate O-atoms (J = -33.4 cm(-1)), with magnetisation measurements at low temperatures and high fields suggesting significant anisotropy. Simulations of high-field and high frequency powder EPR data suggest a single-ion anisotropy D(Mn(III)) = +4.45 cm(-1). DFT calculations also yield an antiferromagnetic exchange for 1, though the magnitude is overestimated (J(DFT) = -71 cm(-1)). Calculations reveal that the antiferromagnetic interaction essentially stems from the Mn(d(x(2)-y(2)))-Cu(d(x(2)-y(2))) interaction. The computed single-ion anisotropy and cluster anisotropy also correlates well with experiment. A larger cluster anisotropy for the S = 3/2 state compared to the single-ion anisotropy of Mn(III) is rationalised on the basis of orbital mixing and various contributions that arise due to the spin-orbit interaction.

U2 - 10.1039/c2dt31995k

DO - 10.1039/c2dt31995k

M3 - Journal article

C2 - 23108057

SN - 1477-9226

VL - 42

SP - 207

EP - 216

JO - Acta chemica Scandinavica. Series A: Physical and inorganic chemistry

JF - Acta chemica Scandinavica. Series A: Physical and inorganic chemistry

IS - 1

ER -