Heptacoordinate Structures of Organotin Halides with Three Phosphine Donors: Halogen-Substituent Effect on Geometry
Heptacoordinate Structures of Organotin Halides with Three Phosphine Donors: Halogen-Substituent Effect on Geometry
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具有三个膦供体的有机锡卤化物的七配位结构：卤素取代基对几何的影响
DOI：
10.1002/ejic.201900524
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发表时间：
2019
影响因子：
2.3
通讯作者：
Nakazawa Hiroshi
中科院分区：
文献类型：
--
作者：
Kameo Hajime;Kawamoto Tatsuya;Sakaki Shigeyoshi;Bourissou Didier;Nakazawa Hiroshi
研究了卤代锡烷{（o-Ph_2 P）C_6H_4}_3SnX（X = F（1），Cl（3），Br（4），I（5））与三个膦配体的七配位化合物的结构。氟锡烷（1）有一个新的七配位几何结构，其中三个膦供体与Sn中心在Sn−F键的反式位置相互作用（a型）。相比之下，氯（3）和溴（4）类似物具有高度扭曲的五边形-双锥几何形状（B形式），碘类似物（5）具有三帽四面体几何形状（c形式）。虽然B和c形式都包括两个与Sn中心反式配位到Cipso原子的膦供体和一个与Sn原子在卤素原子反式位置配位的膦供体，但在B形式中Sn中心周围的几何形状比在c形式中的四面体几何形状扭曲得多。密度泛函理论计算表明，Sn中心卤素原子的存在，由于强的静电和电荷转移（CT）作用，促进了在卤素反式位置的配位，而通过改变卤素取代基的结构修饰是由于卤素原子电负性的差异，因为强电负性的卤素使四面体几何结构形成高度扭曲的结构（Bent's Rule）。
Structural studies were performed on heptacoordinate compounds of halostannanes {(o-Ph2P)C6H4}3SnX (X = F (1), Cl (3), Br (4), I (5)) with three phosphine donors. The fluorostannane (1) has a novel heptacoordinate geometry, in which three phosphine donors interact with the Sn center at the position trans to the Sn−F bond (a form). In contrast, the chloro (3) and bromo (4) analogues have a highly distorted pentagonal-bipyramidal geometry (b form), and the iodo analogue (5) has a tricapped tetrahedral geometry (c form). Although both b and c forms include two phosphine donors coordinating to the Sn center trans to the Cipso atoms and one phosphine donor coordinating to the Sn atom at the position trans to the halogen atom, the geometry around the Sn center is much more distorted from tetrahedral geometry in b form than in c form. DFT calculations showed that the presence of the halogen atom at the Sn center facilitated the coordination at the position trans to the halogen due to strong electrostatic and charge transfer (CT) interactions and the structural modification by changing the halogen substituent arose from the difference in electronegativity of halogen atom because strongly electronegative halogen enabled the formation of highly distorted structure from tetrahedral geometry (Bent's rule).