Wang Mei, Ma Cheng-Bing, Yuan Da-Qiang, Wang Hui-Sheng, Chen Chang-Neng, Liu Qiu-Tian
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
Inorg Chem. 2008 Jul 7;47(13):5580-90. doi: 10.1021/ic701343s. Epub 2008 Jun 10.
A family of manganese complexes, [Mn 5O 3( t-BuPO 3) 2(MeCOO) 5(H 2O)(phen) 2] ( 1), [Mn 5O 3( t-BuPO 3) 2(PhCOO) 5(phen) 2] ( 2), [Mn 4O 2( t-BuPO 3) 2(RCOO) 4(bpy) 2] (R = Me, ( 3); R = Ph, ( 4)), NBu (n) 4[Mn 4O 2(EtCOO) 3(MeCOO) 4(pic) 2] ( 5), NR' 4[Mn 4O 2( i-PrCOO) 7(pic) 2] (R' = Bu (n) , ( 6); R' = Et, ( 7)), were synthesized and characterized. The seven manganese clusters were all prepared from a reaction system containing tert-butylphosphonic acid, Mn(O 2CR) 2 (R = Me, Ph) and NR' 4MnO 4 (R' = Bu (n) , Et) with similar procedures except for using different N-containing ligands (1,10-phenanthroline (phen), 2,2'-bipyridine (bpy) and picolinic acid (picH)) as coligands. The structures of these complexes vary with the N-containing donors. Both the cores of complexes 1 and 2 feature three mu 3-O and two capping t-BuPO 3 (2-) groups bridging five Mn (III) atoms to form a basket-like cage structure. Complexes 3 and 4 both have one [Mn 4(mu 3-O) 2] (8+) core with four coplanar Mn (III) atoms disposed in an extended "butterfly-like" arrangement and two capping mu 3- t-BuPO 3 (2-) binding to three manganese centers above and below the Mn 4 plane. Complexes 5, 6, and 7 all possess one [Mn 4(mu 3-O) 2] (8+) core just as complexes 3 and 4, but they display a folded "butterfly-like" conformation with the four Mn (III) atoms nonplanar. Thus, the seven compounds are classified into three types, and three representative compounds 1.2H 2O.MeOH.MeCN , 3.6H 2O.2MeCOOH , and 5.0.5H 2O have been characterized by IR spectroscopy, ESI-MS spectroscopy, magnetic measurements and in situ UV-vis-NIR spectroelectrochemical analysis. Magnetic susceptibility measurements reveal the existence of both ferromagnetic and antiferromagnetic interactions between the adjacent Mn (III) ions in compound 1.2H 2O.MeOH.MeCN , and antiferromagnetic interactions in 3.6H 2O.2MeCOOH and 5.0.5H 2O. Fitting the experimental data led to the following parameters: J 1 = -2.18 cm (-1), J 2 = 6.93 cm (-1), J 3 = -13.94 cm (-1), J 4 = -9.62 cm (-1), J 5 = -11.17 cm (-1), g = 2.00 ( 1.2H 2O.MeOH.MeCN ), J 1 = -5.41 cm (-1), J 2 = -35.44 cm (-1), g = 2.13, zJ' = -1.55 cm (-1) ( 3.6H 2O.2MeCOOH ) and J 1 = -2.29 cm (-1), J 2 = -35.21 cm (-1), g = 2.02, zJ' = -0.86 cm (-1) ( 5.0.5H 2O ).
合成并表征了一系列锰配合物，[Mn₅O₃(t-BuPO₃)₂(MeCOO)₅(H₂O)(phen)₂] (1)、[Mn₅O₃(t-BuPO₃)₂(PhCOO)₅(phen)₂] (2)、[Mn₄O₂(t-BuPO₃)₂(RCOO)₄(bpy)₂] (R = Me, (3); R = Ph, (4))、NBu₄[Mn₄O₂(EtCOO)₃(MeCOO)₄(pic)₂] (5)、NR₄[Mn₄O₂(i-PrCOO)₇(pic)₂] (R = Bu₄, (6); R = Et, (7))。这七个锰簇合物均由包含叔丁基膦酸、Mn(O₂CR)₂ (R = Me, Ph) 和NR₄MnO₄ (R = Bu₄, Et) 的反应体系通过相似的步骤制备，只是使用了不同的含氮配体（1,10-菲咯啉 (phen)、2,2'-联吡啶 (bpy) 和吡啶甲酸 (picH)）作为共配体。这些配合物的结构随含氮供体的不同而变化。配合物1和2的核心均具有三个μ₃-O和两个盖帽的t-BuPO₃²⁻基团，它们桥连五个Mn(III)原子形成篮状笼状结构。配合物3和4均具有一个[Mn₄(μ₃-O)₂]⁸⁺核心，四个共面的Mn(III)原子呈伸展的“蝴蝶状”排列，两个盖帽的μ₃-t-BuPO₃²⁻与Mn₄平面上方和下方的三个锰中心结合。配合物5、6和7与配合物3和4一样，均具有一个[Mn₄(μ₃-O)₂]⁸⁺核心，但它们呈现出折叠的“蝴蝶状”构象，四个Mn(III)原子不共面。因此，这七个化合物分为三种类型，并且通过红外光谱、电喷雾电离质谱、磁性测量和原位紫外-可见-近红外光谱电化学分析对三种代表性化合物1·2H₂O·MeOH·MeCN、3·6H₂O·2MeCOOH和5·0·5H₂O进行了表征。磁化率测量表明，化合物1·2H₂O·MeOH·MeCN中相邻的Mn(III)离子之间同时存在铁磁和反铁磁相互作用，而在3·6H₂O·2MeCOOH和5·0·5H₂O中存在反铁磁相互作用。对实验数据进行拟合得到以下参数：J₁ = -2.18 cm⁻¹，J₂ = 6.93 cm⁻¹，J₃ = -13.94 cm⁻¹，J₄ = -9.62 cm⁻¹，J₅ = -11.17 cm⁻¹，g = 2.00 (1·2H₂O·MeOH·MeCN)，J₁ = -5.41 cm⁻¹，J₂ = -35.44 cm⁻¹，g = 2.13，zJ' = -1.55 cm⁻¹ (3·6H₂O·2MeCOOH) 以及J₁ = -2.29 cm⁻¹，J₂ = -35.21 cm⁻¹，g = 2.02，zJ' = -0.86 cm⁻¹ (5·0·5H₂O)。
