State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences, Fuzhou, Fujian, 350002 (P. R. China), Fax: Int. code +(591)371-4946.
Chemistry. 1997 Feb;3(2):226-31. doi: 10.1002/chem.19970030210.
A mixture of Na2 MO4 , M(CO)6 , FeCl3 ·6H2 O, and (EtCO)2 O was heated at 120°C to produce the heterooctanuclear clusters Na2 Fe2 [M3 O4 -(O2 CEt)8 ]2 (M = Mo, 1; W, 2). The bioxo-capped clusters Na[M3 O2 (O2 CEt)9 ] (M3 = MoW2 , W3 ) were treated with Fe-(CO)5 , Cr(CO)6 , and Mo(CO)6 in (EtCO)2 O at 120°C to afford Na2 M'2 -[MoW2 O4 (O2 CEt)8 ]2 (M' = Fe, 3; Cr, 4; Mo, 5) and Na2 Mo2 [W3 O4 (O2 CEt)8 ]2 (6), respectively. The isomorphous clusters 1, 2, 5, and 6 were characterized by X-ray crystallography. The structures, similar to those of the analogues Na2 Cr2 [M3 O4 -(O2 CEt)8 ] (M = Mo, 7; W, 8) and Na2 V2 [M3 O4 (O2 CEt)8 ]2 (M = Mo, 9; W, 10), consist of two incomplete cubane-type M3 O4 (O2 Et)8 units centrosymmetrically bridged by two M'(III) metal ions through μ-oxo and propionate groups; the resulting cluster dianions are linked by Na(+) ions into infinite chains. Clusters 1-10 do not dissolve in water and common organic solvents at room temperature. Unlike the chromium(III) clusters 7 and 8, the iron(III) and vanadium(III) clusters 1 and 9 are soluble in aqueous acid solution, as a result of their decomposition into isolated Mo3 O4 cluster units. Temperature-dependent magnetic susceptibilities of 1, 2, and 7-10 were measured over the range 2-200 K and modeled by means of the spin-Hamiltonian H = - 2JS1 S2 to give spin exchange coupling constants J/k of -0.60, -0.72, -1.76, -1.31, -4.80, and -1.46 K, respectively. These figures show that antiferromagnetic spin exchange coupling interactions between the magnetic, bridging M'(III) ions are very weak. These species show characteristic bands in the IR spectra at 740-820 cm(-1) , which can probably be assigned to ṽ(M-μ-O).
一种由 Na2 MO4、M(CO)6、FeCl3·6H2O 和(EtCO)2O 组成的混合物在 120°C 下加热，生成异核十八核簇 Na2 Fe2[M3 O4-(O2CEt)8]2（M=Mo，1；W，2）。生物氧封端的簇 Na[M3 O2(O2CEt)9]（M3=MoW2，W3）与 Fe-(CO)5、Cr(CO)6 和 Mo(CO)6 在（EtCO)2O 中于 120°C 反应，得到 Na2 M'2-[MoW2O4(O2CEt)8]2（M'=Fe，3；Cr，4；Mo，5）和 Na2 Mo2[W3 O4(O2CEt)8]2（6）。1、2、5 和 6 这些同构簇通过 X 射线晶体学进行了表征。这些结构与类似物 Na2 Cr2[M3 O4-(O2CEt)8]（M=Mo，7；W，8）和 Na2 V2[M3 O4(O2CEt)8]2（M=Mo，9；W，10）相似，由两个通过μ-氧和丙酸盐基团桥连的两个不完全笼型M3 O4(O2Et)8单元通过两个 M'（III）金属离子中心对称构成；所得的簇二阴离子通过 Na(+)离子连接成无限链。1-10 簇在室温下不溶解于水和常见有机溶剂。与三价铬簇 7 和 8 不同，三价铁和三价钒簇 1 和 9可溶解于酸性水溶液中，这是由于它们分解为孤立的Mo3 O4簇单元。在 2-200 K 的范围内测量了 1、2 和 7-10 的温度相关磁化率，并通过自旋哈密顿量 H=-2JS1S2 进行了建模，得到了自旋交换耦合常数 J/k 分别为-0.60、-0.72、-1.76、-1.31、-4.80 和-1.46 K。这些数据表明，磁性桥连 M'（III）离子之间的反铁磁自旋交换耦合相互作用非常弱。这些物质在 IR 光谱中在 740-820 cm(-1)处显示出特征带，可能归因于 ṽ（M-μ-O）。
