Much attention has been focused on the tetranuclear manganese clusters in the past few decades because of thei...
Jin-Ying Liu~(1,2) Cheng-Bing Ma~1,Hui Chen~1,Chang-Neng Chen~(1,*) 1 State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,The Chinese Academy of Sciences,Fuzhou,Fujian350002,China 2 Graduate School of the Chinese Academy of Sciences,Beijing 100039,China
A new mixed-ligand Mn（II）complex,namely [Mn（bipy）2（Huca）]·5H2O（1,bipy = 2,2＇-bipyridine,and H3uca = uracil-5-carboxylic acid）has been prepared and characterized by single-crystal X-ray diffraction,FT-IR spectroscopy and thermogravimetric analysis.It crystallizes in monoclinic,space group C2/c with a = 23.597（8）,b = 16.434（5）,c = 15.531（6）,β = 112.785（6）o,C25H28MnN6O9,Mr = 611.47,V = 5553（3）3,Z = 8,μ = 0.538,Dc = 1.463 g/cm3,F（000）= 2536,R = 0.0441 and wR = 0.1230 for all 5227 observed reflections（I 2σ（I））.The manganese（II）center is surrounded by three bidentate chelating ligands,and it displays a severely distorted octahedral geometry,with cis angles ranging from 72.14（6）to 109.78（6）o.Extensive intermolecular hydrogen bonds link the [Mn（bipy）2（Huca）] monomers and lattice water molecules to yield a three-dimensional supramolecular framework.TGA shows complete removal of all lattice water molecules above 270 ℃.
Two diiron dithiolate complexes, （μ-pdt）Fe2（CO）5（C7H10N2） 3 and （μ-edt）-Fe2（CO）5（C7H10N2） 4 （pdt = -S（CH2）3S-, edt = -S（CH2）2S-）, have been synthesized and characterized by single-crystal X-ray diffraction. Complex 3 crystallizes in the monoclinic system, space group P21/c with a = 10.168（4）, b = 11.816（4）, c = 16.595（7） and β = 95.195（6）o; and complex 4 crystallizes in the orthorhombic system, space group P212121 with a = 9.317（3）, b = 11.898（4）, c = 34.006（10） .The distances of Fe（1）–Fe（2） are 2.5058（9） in 3 and 2.4942（10） in 4, falling in the normal range of Fe–Fe bond length （2.49～2.57 ）. The cyclic voltammograms show that 3 and 4 display irreversible reduction peaks （FeIFeI/ FeIFe0） at –1.717 V and –1.673 V vs. Ag/AgCl, respectively. With different acids, complex 3 has distinguishable behavior, two protonations in addition of HBF4-Et2O and single protonation besides HOAc-CH3CN, and complex 4 has a similar action to 3 with HOAc-CH3CN for a semblable structure.
