BIFUNCTIONAL MODEL COMPLEXES ACTIVE IN CARBON-DIOXIDE FIXATION - SYNTHESIS AND X-RAY STRUCTURE OF BIMETALLIC COBALT(I) ALKALI CATION SCHIFF BASE COMPLEXES
BIFUNCTIONAL MODEL COMPLEXES ACTIVE IN CARBON-DIOXIDE FIXATION - SYNTHESIS AND X-RAY STRUCTURE OF BIMETALLIC COBALT(I) ALKALI CATION SCHIFF BASE COMPLEXES
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DOI：
10.1021/ic50202a035
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发表时间：
1979-01-01
影响因子：
4.6
通讯作者：
ZANZARI, AR
中科院分区：
文献类型：
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作者：
FACHINETTI, G;FLORIANI, C;ZANZARI, AR
在四氢呋喃（THF）中，Ar，Ar-亚乙基双（亚水杨基亚氨基））钴（Ⅱ）Co（salen）与锂和钠金属还原，得到具有二氧化碳固定活性的双金属体系[（Co（salen））NaTHF]和[（Co（sal-en））Li（THF）15]。用单晶X-射线衍射方法确定了配合物的结构。它们都含有一个抗磁性钴（I）在一个稍微扭曲的正方形平面的配位几何由于salen配体，通过氧原子协调的碱金属阳离子。[(Co（salen））NaTHF]在正交晶系空间群P2 {2 {1}中结晶，晶格参数a = 7.416（2）π，B= 21.848（9）π，c= 11.639（5）π，和Z= 4。用1579个反射函数解出了结构，并修正到R= 0.030。其晶体结构由无限长链组成，其单体单元为[（Co（salen））2Na 2（THF）2]。它们可以用Na+周围的扭曲八面体共享相反的面来描述。THF和Co（salen）通过氧原子作为两个相邻钠阳离子之间的桥接配体。[(Co（salen））Li（THF）15]为三斜晶系，空间群Pi，晶格参数a= 16.892（3）<$，B= 14.310（3）<$，c= 10.899（3）<$，a= 94.6（2），<$= 99.5（2），= 122.3（2），和Z= 2。结构用直接法解出，用最小二乘法修正，R= 0.089，共2680个反射。在[（Co（salen））Li（THF）15]的结构中，存在两种不同的分子络合物，[（Co（salen））Li（THF）2]和[（Co（salen））2Li 2（THF）2]，比例为2：1。在两种配合物中，L：+均为畸变四面体配位。在第一个配合物中，锂配位的四个氧由Co（salen）和两个THF分子提供，Co（salen）充当双齿螯合配体。在中心对称的四核配合物[（Co（salen））2Li 2（THF）2]中，[（Co（salen））Li（THF）2]中的一个THF氧被一个Co（salen）氧原子取代，该氧原子桥接两个锂阳离子。
Reduction of (Ar, Ar-ethylenebis (salicylideniminato)) cobalt (II), Co (salen), with lithium and sodium metals in tetrahydrofuran, THF, affords the bimetallic systems, which are active in carbon dioxide fixation,[(Co (salen)) NaTHF] and [(Co (sal-en)) Li (THF) 15]. The structures of these complexes have been solved by single-crystal X-ray diffraction methods. Both of them contain a diamagnetic cobalt (I) in a slightly distorted square-planar coordination geometrydue to a salen ligand which coordinates the alkali cation through the oxygen atoms.[(Co (salen)) NaTHF] crystallizes in the orthorhombic space group P2 {2 {1 with lattice parameters a- 7.416 (2) Á, b= 21.848 (9) Á, c= 11.639 (5) Á, and Z= 4. The structure has been solved by using 1579 observedreflections and refined to R= 0.030. The crystal structure consists of infinite chains, whose monomeric unit is [(Co (salen)) 2Na2 (THF) 2]. They can be described by distorted octahedra around Na+ sharing the opposite faces. Both THF and Co (salen) act, through the oxygen atoms, as bridging ligands between two adjacent sodium cations.[(Co (salen)) Li (THF) 15] is triclinic, space group Pi, with lattice parameters a= 16.892 (3) Á, b= 14.310 (3) Á, c= 10.899 (3) Á, a= 94.6 (2), ß= 99.5 (2),= 122.3 (2), and Z= 2. The structure has been solvedby direct methods and refined by least-squares methods to R= 0.089, for 2680 reflections. In the structure of [(Co (sal-en)) Li (THF) 15] there are two different molecular complexes,[(Co (salen)) Li (THF) 2] and [(Co (salen)) 2Li2 (THF) 2], in a 2: 1 ratio. In bothcomplexes, L:+ is in a distorted tetrahedral coordination. In the first complex, the four oxygens for the lithium coordination are provided by Co (salen), acting as a bidentate chelating ligand, and two THF molecules. In the centrosymmetric tetranuclear complex [(Co (salen)) 2Li2 (THF) 2] one of the THF oxygens of [(Co (salen)) Li (THF) 2j is replaced by a Co (salen) oxygen atom which bridges two lithium cations.