Stereoselective Photoreactions With New Coppe (1) Complexes Possessing A Chiral Conjugate Ligand

具有手性共轭配体的 New Coppe (1) 配合物的立体选择性光反应

基本信息

批准号：
06640729
负责人：
SAKAKI Shigeyoshi
金额：
$ 1.15万
依托单位：
KUMAMOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640729/
关键词：
Chiral Copper (I) Complex Photo-asymmetric reduction Cobalt (III) Complex Photo-asymmetric synthesis Excited state lifetime Solvent effects Photoinduced electron transfer Reaction mechanism

项目摘要

We synthesized a new chiral 2,2'-bipyridine ligand possessing R (+) -alpha-methylbenzyeamine, 5,5'-di (-) -methylbenzylamido-4,4'-6,6'-tetramethyl-2,2'-bipyridine (-) -tmdcbpy, and its Cu (I) complexes, [Cu ( (-) -tmdcbpy) (PPh_3) _2] 1, [Cu ( (-) -tmdcbpy) (P (C_6H_4-SO_3-m) Ph_2) _2] ^-2, [Cu ( (-) -tmdcbpy) ( (+) -diop) ] ^+3, and [Cu ( (-) -tmdcbpy) ( (-) -diop) ] ^+ 4. Using these Cu (I) complexes, stereoselective photoreduction of [Cu (edta) ] ^-was successfully carried out upon irradiation of near UV light corresponding to the MLCT absorption band of these Cu (I) complexes. The best stereoselectivity was 44%e.e. when 1 was used in ethanol-water (75 : 25 v/v). On the other hand, the stereoselectivity decreases to about 17%e.e. when 2 was used. The quenching experiments with [Co (edta) ] ^-indicated clearly that the reaction of 1 proceeds through dynamic and static quenching mechanism but the reaction of 2 takes place only through static quenching mechanism. These interesting diff … More erences between 1 and 2 are interpreted in terms of the electrostatic interaction : because 1 is positively charged, 1 can easily form an adduct with negatively charged [Co (edta) ] ^-and the interaction of [Cu^<11> ( (-) -tmdcbpy) (PPh_3) _2] ^<2+> with [Co^<11> (edta) ] ^<2->is strong due to the electrostatic attraction. On the other hand, the negatively charge 2 can not form a stable adduct in the ground state, and also the interaction of [Cu^<11> ( (-) -tmdcbpy) (P (C_6H_4SO_3-m) Ph) _2] ^0with [Co (edta) ] ^<2->is weak because of the lack of electrostatic attraction.Then, photo-asymmetric synthesis of [Co (edta) ] ^-was successfully carried out from Co (OAc) _2and H_4edta or Na_4edta, using these Cu (I) complexes with oxygen gas under upon irradiation of near UV light., In this photosynthetic reaction, DELTA- [Co (edta) ] ^-was produced in the excess when H_4edta was used. This reaction was possible only in DMSO,and the selectivity significantly depends on the kind of edta source, counter anion of Co salt. Less

我们合成了一种新型手性2,2'-双吡啶配体，具有R（+）-Alpha-甲基苯甲胺，5,5'-di（ - ）-Methylbenzylbenzylamido-4,4,4,4,4,4,6,6'-四甲基 - 四甲基-2,2'-二吡啶胺（ -tmdcbpy）（pph_3）_2] 1，[cu（（ - ）-tmdcbpy）（p（c_6h_4-so_3-m）ph_2）_2] _2] ^-2，[cu（（ - ）-tmdcbpy）（tmdcbpy）（（+）-diop）（（（+）-diop） - （（+）-diop）+3，和[CU 3，和（） ^+ 4。使用这些Cu（i）复合物，[Cu（edta）] ^的立体选择性光导导在对应于这些Cu（I）复合物的MLCT抽象带的近紫外光线后成功地进行了。最好的立体选择性为44％E.E。当1用于乙醇水（75：25 V/V）时。另一方面，立体选择性降低到约17％。当使用2时。使用[CO（EDTA）] ^的淬灭实验清楚地表明，1的反应通过动态和静态淬灭机制进行，但2的反应仅通过静态淬灭机制进行。这些有趣的差异……通过静电相互作用来解释1和2之间的更多效果：由于1是积极充电，因此很容易形成带有负电荷的[CO（edta）] ^ - [Cu ^<11>（（ - TMDCBPY）-TMDCBPY）（PPH_3）_2] _2] _2] _2] ^<2- <11 ^<11> [CU ^<11>（（ - TMDCBPY）的相互作用）与[Cu ^<11>（（ - tmdcbpy）的相互作用）。静电吸引力。另一方面，负电荷2无法在基态下形成稳定的加合物，并且[Cu ^<11>（（（ - ）-TMDCBPY）的相互作用也很弱，因为缺乏静电吸引力，因此很弱。然后，使用这些Cu（i）或Na_4Edta进行的[CO（EDTA）] ^ - 使用这些Cu（i）复合物在近UV光照射后，在这种光合作用反应中，使用这些Cu（i）复合物，在hyta frof。被使用。该反应仅在DMSO中才有可能，并且选择性显着取决于EDTA源的类型，即Co盐的反阴离子。较少的