stablize the structures of [Ln(d/l-hfc)4]− or the dissociated tris(d/l-hfc)Ln(III) species in solution for a longer time than that of the Na+ cation, and it is important that the Cs+ ion successfully lock the configurational chirality around the Yb3+ center of the complex species in solution. This is reasoned by the short Cs+⋯FC, Cs+⋯O–Yb and Cs+⋯Yb3+ interactions observed in the crystalstructure of α-5 and
Novel Configurational Structures of Sodium Tetrakis(3-heptafluorobutylryl-(+)-camphorato) Ln(III) Complexes with a Trapped Na<sup>+</sup> by Na<sup>+</sup>···FC Interactions in the Solid State and in Solution
作者:Dai Shirotani、Takayoshi Suzuki、Sumio Kaizaki
DOI:10.1021/ic0606633
日期:2006.8.1
For newly prepared sodium tetrakis( 3-heptafluorobutylryl-( +)-camphorato) Ln( III) complexes, the X-ray crystal analysis revealed an unprecedented pseudo-achiral dodecahedron ( DD-8 ( D-2d)), whereas in CHCl3 solution, the exciton CD and F-19 NMR spectra showed a novel chiral Delta-SAPR-8 ( C-4) configuration which is stereospecifically formed by a trapped Na+ ion with Na+center dot center dot center dot FC ( fluorocarbon) interactions.
Chiral Polysiloxane‐Fixed Metal 1,3‐Diketonates (Chirasil‐Metals) as Catalytic Lewis Acids for a Hetero Diels‐Alder Reaction ‐Inversion of Enantioselectivity Upon Catalyst ‐Polymer Binding
作者:Fritz Keller、Hilmar Weinmann、Volker Schurig
DOI:10.1002/cber.19971300711
日期:1997.7
Lewis acid catalyst (1R)-(+)-oxovanadium(1V) bis[3- heptafluorobutanoylcamphorate] [(+)-5a] at the C-10 position of the camphor moiety yielding the novel chiral polymeric (1S)-( +)-oxovanadium(1V) bis[3-heptafluorobutanoylcamphorate] -dimethylpolysiloxane [( +)-6a][1]. The Lewis acid promoted hetero Diels-Alder reaction of trans-l-methoxy-3-(trimethylsilyloxy)- 1,3-butadiene (1) and benzaldehyde (2) is
ethynyl)benzene), were prepared for elucidating the relationship between their structural distortions, ligand-to-metal charge transfer (LMCT), and circularlypolarizedluminescence (CPL) properties. Their strain factors in the ligands were evaluated using crystallographic data obtained by single-crystal X-ray structural analyses. The characteristics of the LMCT excited states were estimated from theoretical
三种具有不同扭曲手性配体的 Eu( III ) 配位聚合物,[Eu(+tfc) 3 ( p -dpeb)] n、[Eu(+pfc) 3 ( p -dpeb)] n和 [Eu(+ ) hfc) 3 ( p -dpeb)] n (+tfc: (+)-3-(trifluoroacetyl)camphorate, +pfc: (+)-3-(pentafluorpropionyl)camphorate, +hfc: (+)-3-(heptafluorutyryl) ) 樟脑酸, p-dpeb:1,4-双(二苯基磷酸乙炔基)苯),用于阐明其结构扭曲、配体到金属电荷转移 (LMCT) 和圆偏振发光 (CPL) 特性之间的关系。使用通过单晶 X 射线结构分析获得的晶体学数据评估它们在配体中的应变因子。LMCT 激发态的特征是从理论计算中估计出来的。在手性配体中引入庞大的取代基,使 β-二酮化合物的结构发生扭曲,并改变了跃迁电偶极矩的方向,这与