Chiral Self-Recognition between Stereogenic Tetrapalladium Units Affording Pd8 Chains Supported by Homochiral Tetraphosphines
Chiral Self-Recognition between Stereogenic Tetrapalladium Units Affording Pd8 Chains Supported by Homochiral Tetraphosphines
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同手性四膦支持的立体四钯单元之间的手性自我识别，提供 Pd8 链
DOI：
10.1002/chem.201605146
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Takayuki
中科院分区：
文献类型：
--
作者：
Tanase;Tomoaki; Morita;Konomi; Otaki;Risa; Yamamoto;Kana; Kaneko;Yukino; Nakamae;Kanako; Kure;Bunsho; Nakajima;Takayuki
以手性四膦盐rac‐bis[(diphenylphosphinomethyl)phenylphosphino]methane(rac-dpmppm)为原料，合成了[Pd8(μ-rac-dpmppm)4L2](BF4)4(L=CH3CN，DMF，XylNC)，[Pd8(μ-rac-dpmppm)4](BF4)4，[Pd8(μ-rac-dpmppm)4(Cl)2](BF4)2等在溶液中稳定存在的线型八钯链，并用光谱学和结晶学方法表征了它们的结构。变温核磁共振研究表明，在[D7]DMF中，[Pd8(μ-rac-dpmppm)4(μ-rac-dpmppm)4(Dmf)2](Bf4)4和[pd8(μ-Meso-dpmppm)4(Dmf)2]-(Bf4)4的1：1混合物的变温核磁共振研究表明，Pd8链在较高的温度(T=140 °C)下解离成{Pd4(μ-rac-dpmppm)2}2+和{Pd4(μ-Meso-dpmppm)2}2+的Pd4单元，它们在较低的温度(T<；60 °C)，通过立体生成的四钯单元之间完美的手性自识别。
By using a chiral tetraphosphine,rac‐bis[(diphenylphosphinomethyl)phenylphosphino]methane (rac‐dpmppm), linear octapalladium chains were synthesized as discrete molecules of [Pd8(μ‐rac‐dpmppm)4L2](BF4)4(L=CH3CN, dmf, XylNC), [Pd8(μ‐rac‐dpmppm)4](BF4)4, and [Pd8(μ‐rac‐dpmppm)4(Cl)2](BF4)2, which are stable in the solution states and characterized by spectroscopic and crystallographic methods to reveal the octapalladium chains supported by homochiral four tetraphosphines. Variable‐temperature NMR studies for a 1:1 mixture of [Pd8(μ‐rac‐dpmppm)4(dmf)2](BF4)4and [Pd8(μ‐meso‐dpmppm)4(dmf)2]‐(BF4)4in [D7]DMF revealed that the Pd8chains were dissociated at higher temperature (T≈140 °C) into the Pd4units of {Pd4(μ‐rac‐dpmppm)2}2+and {Pd4(μ‐meso‐dpmppm)2}2+, and they were thermodynamically self‐aligned to restore the Pd8chains at lower temperature (T<60 °C), through perfect chiral self‐recognition between the stereogenic tetrapalladium units.