Hemilabile and reversible carbon monoxide binding properties of iron(II), cobalt(II) and nickel(II) complexes containing a new tridentate P-S-N ligand.
Hemilabile and reversible carbon monoxide binding properties of iron(II), cobalt(II) and nickel(II) complexes containing a new tridentate P-S-N ligand.
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DOI：
10.1039/c1dt11248a
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发表时间：
2012-01
影响因子：
4
通讯作者：
Christopher W. Tate;A. deMello;A. Gee;S. Kealey;R. Vilar;Andrew J. P. White;N. Long
中科院分区：
文献类型：
--
作者：
Christopher W. Tate;A. deMello;A. Gee;S. Kealey;R. Vilar;Andrew J. P. White;N. Long
几种第一行过渡金属配合物[M(1)(2)](X)(2){其中1 = Ph(2)PCH(2)CH(2)S(2- c (6)H(4)NH(2))；M = Fe(II), X = BF(4)(-) (2)；M = Co（II）、X = BF(4)(-)(3)、Ni（II）、X = ClO(4)(-)(4)}用两种当量的新P-S-N配体Ph(2)PCH(2)CH(2)S(2- c (6)H(4)NH(2)) 1与一种当量的合适的[M(OH(2))(6)](X)(2)前驱体在乙腈中反应制备了M = Co（II）、X = BF(4)(3)、Ni（II）、X = ClO(4)(4)}。在固体状态下，配合物2-4以扭曲的中心对称八面体结构存在，具有全反式排列的面盖配体。2和3与一氧化碳流（1atm）在乙腈中反应5min，生成铁（II）单羰基络合物[Fe(CO)(1)(2)](BF(4))(2)2a和钴（II）二羰基络合物[CO (CO)(2)(1)(2)](BF(4))(2)3a，可在固体状态下分离。通过在乙腈中加热回流2a样品5分钟或在真空中120°C加热3a固体样品4小时，可以完全去除CO。一氧化碳的结合在2和3中是完全可逆的，并且可以在多个循环中重复。当同样的捕获反应在非常低的放射性化学（11）CO浓度下进行时，金属羰基物种不再形成。很可能是（11）CO加合物形成的动力学太慢，无法在应用的放射化学条件下有效捕获。
Several first-row transition metal complexes of the formulation [M(1)(2)](X)(2) {where 1 = Ph(2)PCH(2)CH(2)S(2-C(6)H(4)NH(2)); M = Fe(II), X = BF(4)(-) (2); M = Co(II), X = BF(4)(-) (3), Ni(II), X = ClO(4)(-) (4)} have been prepared by reaction of two equivalents of the new P-S-N ligand Ph(2)PCH(2)CH(2)S(2-C(6)H(4)NH(2)) 1 with one equivalent of the appropriate [M(OH(2))(6)](X)(2) precursor in acetonitrile. In the solid state, complexes 2-4 exist as distorted centrosymmetric octahedral structures featuring facially capping ligands in an all-trans arrangement. Reaction of 2 and 3 with a stream of carbon monoxide (1 atm.) for 5 min in acetonitrile generates iron(II) monocarbonyl species of formulation [Fe(CO)(1)(2)](BF(4))(2)2a, and a cobalt(II) dicarbonyl complex, [Co(CO)(2)(1)(2)](BF(4))(2)3a, which can be isolated in the solid state. Complete removal of CO is achieved by either heating to reflux samples of 2a in acetonitrile for 5 min or by heating solid samples of 3a at 120 °C in vacuo over a period of 4 h. The binding of carbon monoxide is fully reversible for 2 and 3 and can be repeated over multiple cycles. When the same trapping reactions were carried out with very low radiochemical (11)CO concentrations, metal carbonyl species were no longer formed. It is likely that the kinetics of (11)CO adduct formation are too slow to allow for effective trapping under the applied radiochemical conditions.