TY - JOUR
T1 - Synthesis and spectroscopic and magnetic characterization of tris(3,5-dimethylpyrazol-1-yl)borate iron tricyanide building blocks, a cluster, and a one-dimensional chain of squares
AU - Li, Dongfeng
AU - Parkin, Sean
AU - Wang, Guangbin
AU - Yee, Gordon T.
AU - Holmes, Stephen M.
PY - 2006/3/6
Y1 - 2006/3/6
N2 - The synthesis and spectroscopic and magnetic characterization of several hydridotris(3,5-dimethylpyrazol-1yl)-borate (Tp*) iron(II) and iron(III) tricyanide complexes, a rectangular cluster, and a one-dimensional chain of squares are described. Treatment of [NEt4][(Tp*)Fe III(CN)3] (3) with manganese(II) triflate in dimethylformamide (DMF) affords rectangular clusters (6, {[(Tp*)Fe(CN) 2(μ-CN)Mn(DMF)4]2[OTf]2} ·2DMF), while tosylate salts afford one-dimensional networks (5, {Mn II(DMF)2(μ-OTs)(μ-NC)2(NC)Fe III(Tp*)}n) containing embedded [(Tp*) 2FeIII2MnII2(CN) 6]2+ clusters via in situ trapping; the cluster and network crystallize in the monoclinic (6, P21/n) and triclinic (5, P1) space groups, respectively. The 1-D network (5) appears to be derived from {cis-(μ-O3SC6H4Me)2Mn II(DMF)4}n (4, P21/n), which is obtained via crystallization of Mn(OTs)2 from DMF/Et2O mixtures. For 4, magnetic studies indicate that the MnII centers are magnetically isolated, with calculated J, g, and θ constants of 6.7 × 10-3 cm-1, 2.03, and -0.52 K. Additional magnetic studies of 5 and 6 indicate that the [(Tp*)FeIII(CN) 3]- centers are highly anisotropic (g = 2.9) and are antiferromagnetically coupled to adjacent MnII centers. For 5 and 6, fitting of the χT vs T data via the Curie-Weiss expression affords Curie (6.25 and 10.8 cm3 K mol-1) and Weiss (-14.37 and -8.80 K) constants that are consistent with antiferromagnetically coupled low-spin FeIII and high-spin MnII centers; least-squares fitting of the χT vs T data using molecular field theory affords gavg., J1, J2, and J′ values of 2.25, -1.72, -0.58, and -0.12 cm-1 for 5. Overall, bridging tosylates appear to be poor communicators of spin information. For 6, the g, J1, and J 2 (2.15, -2.02, and -0.78 cm-1) values were obtained via least-squares fitting of the χT vs T data using an expression derived using the Kambe vector coupling method; simulations of the data via MAGPACK afford gavg. and Jiso values of 2.1 and -2.1 cm-1.
AB - The synthesis and spectroscopic and magnetic characterization of several hydridotris(3,5-dimethylpyrazol-1yl)-borate (Tp*) iron(II) and iron(III) tricyanide complexes, a rectangular cluster, and a one-dimensional chain of squares are described. Treatment of [NEt4][(Tp*)Fe III(CN)3] (3) with manganese(II) triflate in dimethylformamide (DMF) affords rectangular clusters (6, {[(Tp*)Fe(CN) 2(μ-CN)Mn(DMF)4]2[OTf]2} ·2DMF), while tosylate salts afford one-dimensional networks (5, {Mn II(DMF)2(μ-OTs)(μ-NC)2(NC)Fe III(Tp*)}n) containing embedded [(Tp*) 2FeIII2MnII2(CN) 6]2+ clusters via in situ trapping; the cluster and network crystallize in the monoclinic (6, P21/n) and triclinic (5, P1) space groups, respectively. The 1-D network (5) appears to be derived from {cis-(μ-O3SC6H4Me)2Mn II(DMF)4}n (4, P21/n), which is obtained via crystallization of Mn(OTs)2 from DMF/Et2O mixtures. For 4, magnetic studies indicate that the MnII centers are magnetically isolated, with calculated J, g, and θ constants of 6.7 × 10-3 cm-1, 2.03, and -0.52 K. Additional magnetic studies of 5 and 6 indicate that the [(Tp*)FeIII(CN) 3]- centers are highly anisotropic (g = 2.9) and are antiferromagnetically coupled to adjacent MnII centers. For 5 and 6, fitting of the χT vs T data via the Curie-Weiss expression affords Curie (6.25 and 10.8 cm3 K mol-1) and Weiss (-14.37 and -8.80 K) constants that are consistent with antiferromagnetically coupled low-spin FeIII and high-spin MnII centers; least-squares fitting of the χT vs T data using molecular field theory affords gavg., J1, J2, and J′ values of 2.25, -1.72, -0.58, and -0.12 cm-1 for 5. Overall, bridging tosylates appear to be poor communicators of spin information. For 6, the g, J1, and J 2 (2.15, -2.02, and -0.78 cm-1) values were obtained via least-squares fitting of the χT vs T data using an expression derived using the Kambe vector coupling method; simulations of the data via MAGPACK afford gavg. and Jiso values of 2.1 and -2.1 cm-1.
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U2 - 10.1021/ic051044h
DO - 10.1021/ic051044h
M3 - Article
C2 - 16499356
AN - SCOPUS:33645106401
SN - 0020-1669
VL - 45
SP - 1951
EP - 1959
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 5
ER -