摘要
分别用绝对不对称合成和改进的拆分方法制备标题配合物!-(+)D-cis-[CoBr(NH3)(en)2]Br2(1)和'-(-)D-cis-[CoBr(NH3)(en)2]Br2(2),以及制备了cis-[CoBr(NH3)(en)2]Br·22H2O(3)(en=1,2-乙二胺).用元素分析、差热-热重、旋光度、UV-Vis、CD光谱等对产物进行了表征.通过CD光谱法获得了绝对不对称合成Co(III)配合物的产物ee值分布图.当利用绝对不对称合成得到的手性Co(III)配合物去“逆向拆分”外消旋溴代樟脑磺酸铵[NH4(dl-BCS)]时只获得部分拆分,初步认为这与交互拆分过程中阴阳离子之间的有效手性识别有关,对于手性Co(III)配合物的绝对不对称合成还提出了一个新的反应机理,即“催化-结晶诱导”机理.
The absolute asymmetric synthesis of the title complexes ∧-（＋）D-cis-[CoBr（NH3）（en）2]Br2（1） and △-（-）D-cis- [CoBr（NH3）（en）2]Br2（2）（en=1,2-ethylenediamine） as well as the improved optical resolution of cis-[CoBr（NH3）（en）2]Br2·2H2O（3） are described in detail. The products were characterized by means of elemental analysis, TG-DTA, optical rotation, UV-Vis, and CD spectra. The distribution of enantiomeric excess（ee） of cis-[CoBr（NH3）（en）2]Br2 in the absolute asymmetric synthesis was obtained by the measurements of their CD spectra. It was found that the complete resolution of rac-cis-[CoBr（NH3）（en）2]Br2·2H2O was achieved by use of NH4（d-BCS） （ammonium d-ot-bromocamphor-π- sulfonate） or NH4（l-BCS） while NH4（dl-BCS） could only be partially resolved by chiral cis-[CoBr（NH3）（en）2]Br2·2H2O at the same condition. It is deduced that there are notable differences in the chiral discrimination of the reciprocal resolution between cis-[CoBr（NH3）（en）2]Br2. Moreover, a new ＂catalysis-crystal induction＂ mechanism in the preparation of the chiral Co（Ⅲ） complex is put forward.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2006年第5期608-615,共8页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(20171037
20373056)
福建省自然科学基金(C0020001)资助项目
