TY - JOUR
T1 - Syntheses, structures, magnetic properties, and density functional theory magneto-structural correlations of bis(μ-phenoxo) and bis(μ-phenoxo)-μ- acetate/bis(μ-phenoxo)-bis(μ-acetate) dinuclear FeIIINi II compounds
AU - Hazra, Susanta
AU - Bhattacharya, Sagarika
AU - Singh, Mukesh Kumar
AU - Carrella, Luca
AU - Rentschler, Eva
AU - Weyhermueller, Thomas
AU - Rajaraman, Gopalan
AU - Mohanta, Sasankasekhar
PY - 2013/11/18
Y1 - 2013/11/18
N2 - The bis(μ-phenoxo) FeIIINiII compound [Fe III(N3)2LNiII(H2O) (CH3CN)](ClO4) (1) and the bis(μ-phenoxo)-μ-acetate/ bis(μ-phenoxo)-bis(μ-acetate) FeIIINiII compound {[FeIII(OAc)LNiII(H2O)(μ-OAc)] 0.6·[FeIIILNiII(μ-OAc) 2]0.4}(ClO4)·1.1H2O (2) have been synthesized from the Robson type tetraiminodiphenol macrocyclic ligand H2L, which is the [2 + 2] condensation product of 4-methyl-2,6-diformylphenol and 2,2′-dimethyl-1,3-diaminopropane. Single-crystal X-ray structures of both compounds have been determined. The cationic part of the dinuclear compound 2 is a cocrystal of the two species [FeIII(OAc)LNiII(H2O)(μ-OAc)]+ (2A) and [FeIIILNiII(μ-OAc)2]+ (2B) with weights of 60% of the former and 40% of the latter. While 2A is a triply bridged bis(μ-phenoxo)-μ-acetate system, 2B is a quadruply bridged bis(μ-phenoxo)-bis(μ-acetate) system. Variable-temperature (2-300 K) magnetic studies reveal antiferromagnetic interaction in 1 and ferromagnetic interaction in 2 with J values of -3.14 and 7.36 cm-1, respectively (H = -2JS1·S2). Broken-symmetry density functional calculations of exchange interaction have been performed on complexes 1 and 2 and also on previously published related compounds, providing good numerical estimates of J values in comparison to experiments. The electronic origin of the difference in magnetic behavior of 1 and 2 has been well understood from MO analyses and computed overlap integrals of BS empty orbitals. The role of acetate and thus its complementarity/countercomplementarity effect on the magnetic properties of diphenoxo-bridged FeIIINiII compounds have been determined on computing J values of model compounds by replacing bridging acetate and nonbridging acetate ligand(s) by water ligands in the model compounds derived from 2A,B. The DFT calculations have also been extended to develop several magneto-structural correlations in these types of complexes, and the correlations focus on the role of Fe-O-Ni bridge angle, average Fe/Ni-O bridge distance, Fe-O-Ni-O dihedral angle, and out-of-plane shift of the phenoxo group.
AB - The bis(μ-phenoxo) FeIIINiII compound [Fe III(N3)2LNiII(H2O) (CH3CN)](ClO4) (1) and the bis(μ-phenoxo)-μ-acetate/ bis(μ-phenoxo)-bis(μ-acetate) FeIIINiII compound {[FeIII(OAc)LNiII(H2O)(μ-OAc)] 0.6·[FeIIILNiII(μ-OAc) 2]0.4}(ClO4)·1.1H2O (2) have been synthesized from the Robson type tetraiminodiphenol macrocyclic ligand H2L, which is the [2 + 2] condensation product of 4-methyl-2,6-diformylphenol and 2,2′-dimethyl-1,3-diaminopropane. Single-crystal X-ray structures of both compounds have been determined. The cationic part of the dinuclear compound 2 is a cocrystal of the two species [FeIII(OAc)LNiII(H2O)(μ-OAc)]+ (2A) and [FeIIILNiII(μ-OAc)2]+ (2B) with weights of 60% of the former and 40% of the latter. While 2A is a triply bridged bis(μ-phenoxo)-μ-acetate system, 2B is a quadruply bridged bis(μ-phenoxo)-bis(μ-acetate) system. Variable-temperature (2-300 K) magnetic studies reveal antiferromagnetic interaction in 1 and ferromagnetic interaction in 2 with J values of -3.14 and 7.36 cm-1, respectively (H = -2JS1·S2). Broken-symmetry density functional calculations of exchange interaction have been performed on complexes 1 and 2 and also on previously published related compounds, providing good numerical estimates of J values in comparison to experiments. The electronic origin of the difference in magnetic behavior of 1 and 2 has been well understood from MO analyses and computed overlap integrals of BS empty orbitals. The role of acetate and thus its complementarity/countercomplementarity effect on the magnetic properties of diphenoxo-bridged FeIIINiII compounds have been determined on computing J values of model compounds by replacing bridging acetate and nonbridging acetate ligand(s) by water ligands in the model compounds derived from 2A,B. The DFT calculations have also been extended to develop several magneto-structural correlations in these types of complexes, and the correlations focus on the role of Fe-O-Ni bridge angle, average Fe/Ni-O bridge distance, Fe-O-Ni-O dihedral angle, and out-of-plane shift of the phenoxo group.
UR - http://www.scopus.com/inward/record.url?scp=84888104654&partnerID=8YFLogxK
U2 - 10.1021/ic400345w
DO - 10.1021/ic400345w
M3 - Article
AN - SCOPUS:84888104654
SN - 0020-1669
VL - 52
SP - 12881
EP - 12892
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 22
ER -