Synthesis and characterization of high-spin [(CO)3FeII(CO2R)3]2FeII complexes formed by thermolysis of cis-(CO)4Fe(CO2R)2 (R = Me, t-Bu, allyl, 1,1′-dimethylallyl).: X-ray crystal structure of the allyl derivative
Synthesis and characterization of high-spin [(CO)3FeII(CO2R)3]2FeII complexes formed by thermolysis of cis-(CO)4Fe(CO2R)2 (R = Me, t-Bu, allyl, 1,1′-dimethylallyl).: X-ray crystal structure of the allyl derivative
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DOI：
10.1021/om011097g
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发表时间：
2002-04-29
期刊：
影响因子：
2.8
通讯作者：
Varret, F
中科院分区：
文献类型：
--
作者：
Le Gall, N;Luart, D;Varret, F
顺式双(烷氧基羰基)单体(CO)(4)Fe(CO2R)(2)(1)在30℃下热分解得到新的三金属化合物[(CO)(3)Fe(Mu，ETA(2)-CO2R)(3)](2)Fe(R=Me(2a)，t-Bu(2b)，Alyl(2c)，1，1‘-二甲基烯丙基(2d))，而不是预期的碳-碳偶联成草酸盐。H-1和C-13核磁共振谱表明，这些配合物2是由两个[(CO)(3)Fe(CO2R)(3)](-)配体包围的中心Fe(II)，是顺磁性的。2a和2d的穆斯堡尔研究表明，这些络合物的中心铁原子具有高自旋组态，而两个侧面铁原子的自旋组态较低。FeC-[(CO)(3)Fe(CO2R)(3)](-)阴离子与FeCl2反应容易形成这些配合物2，表明I的热析出可通过缔合机制形成2，形成[(CO)(3)Fe(CO2R)(3)]模式。2在50℃下进一步热分解得到醇、Fe(CO)(5)、一氧化碳和双(烷基碳酸盐)。
Instead of the expected carbon-carbon coupling into oxalates, thermolysis at 30 degreesC of the cis-bis(alkoxycarbonyl) monomers (CO)(4)Fe(CO2R)(2) (1) affords the novel trimetallic compounds [(CO)(3)Fe(mu,eta(2)-CO2R)(3)](2)Fe (R = Me (2a), t-Bu (2b), allyl (2c), 1,1'-dimethylallyl (2d)). As-shown by H-1 and C-13 NMR, these complexes 2, which can be described as a central Fe(II) surrounded by two [(CO)(3)Fe(CO2R)(3)](-) ligands, are paramagnetic. A Mossbauer study of 2a and 2d revealed that these complexes display a high-spin configuration of their central iron atom and a low-spin configuration of the two lateral iron atoms. The easy formation of these complexes 2 by reacting fac-[(CO)(3)Fe(CO2R)(3)](-) anions with FeCl2 suggests that formation of 2 by thermal evolution of I could occur via an associative mechanism, giving rise to the [(CO)(3)Fe(CO2R)(3)] pattern. Further thermolysis of 2 at 50 degreesC affords alcohols, Fe(CO)(5), carbon monoxide, and bis(alkyl carbonates).