Mechanism of the low-energy fluxional process in[Fe3(CO)12-nLn] (n = 0–2): aperspective
Mechanism of the low-energy fluxional process in[Fe3(CO)12-nLn] (n = 0–2): aperspective
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[Fe3(CO)12-nLn] (n = 0–2) 中低能流变过程的机制：视角
DOI：
10.1039/a606981i
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
B. Mann
中科院分区：
文献类型：
--
作者：
B. Mann
Burgi和Dunitz的方法，使用晶体结构来映射
羰基化合物的交换途径，已被应用于
[Fe
3
（CO）
12
及其衍生物。已经表明
交换路径遵循协调一致的预测，
开闭桥机构。数据不一致
其他拟议机制。它还表明，
协调的桥打开和桥关闭机构同样可以
被描述为铁的旋转
3
三角形或
羰基二十面体
10
轴线
二十面体通过赤道配体。该机制已被用于
来解释最低能量的流动机制，
[Fe
3
（CO）
12
]，在溶液和固体中均为
状态，以[Fe
3
（CO）
11
L]
[L = PMe
2
Ph、P（OR）
3
,
CNBu
不
、CNCF
3
在溶液中，在
[Fe
3
（CO）
10
L
2
]
[L = P（OR）
3
（R = Me、Et或
PR
我
）]溶液和[Fe
2
Os（CO）
12
]
在固体状态下。审查的其他机制是
C
2
由于约翰逊的振动机制，旋转
或者是铁
3
三角形或羰基二十面体
a S
10
二十面体的轴通过桥
配体和轴向配体上的非桥铁由于伦茨，和
60°旋转
3
轴线
Fe
3
三角形由于汉森。有人认为，配体
多面体模型，虽然非常优雅，但具有误导性，并导致
不可能的机制使用原始局部键合的方法
模型推荐。
The methods of Burgi and Dunitz, using crystal structures to map
out an exchange pathway for the carbonyls, have been applied to
[Fe
3
(CO)
12
] and its derivatives. It has been shown
that the exchange pathway follows that predicted by the concerted
bridge-opening and bridge-closing mechanism. The data are inconsistent
with other proposed mechanisms. It has also been shown that the
concerted bridge-opening and bridge-closing mechanism can equally be
described as a rotation of either the Fe
3
triangle or the
carbonyl icosahedron about a S
10
axis of the
icosahedron through the equatorial ligands. This mechanism has been used
to explain the lowest-energy fluxional mechanism in
[Fe
3
(CO)
12
], both in solution and in the solid
state, in [Fe
3
(CO)
11
L]
[L = PMe
2
Ph, P(OR)
3
,
CNBu
t
, CNCF
3
] in solution, in
[Fe
3
(CO)
10
L
2
]
[L = P(OR)
3
(R = Me, Et or
Pr
i
)] in solution and in [Fe
2
Os(CO)
12
]
in the solid state. The other mechanisms examined are the
C
2
libration mechanism due to Johnson, the rotation
of either the Fe
3
triangle or the carbonyl icosahedron about
a S
10
axis of the icosahedron through a bridging
ligand and an axial ligand on the unbridged iron due to Lentz, and the
60° rotation about the C
3
axis of the
Fe
3
triangle due to Hanson. It is argued that the Ligand
Polyhedral Model, albeit very elegant, is misleading and has led to
improbable mechanisms. The approach using the original Local Bonding
Model is recommended.