Casanova David, Alemany Pere, Bofill Josep M, Alvarez Santiago
Departament de Química Inorgànica, Centre de Recerca en Química Teòrica (CeRQT), Universitat de Barcelona, Diagonal 647, 08028 Barcelona, Spain.
Chemistry. 2003 Mar 17;9(6):1281-95. doi: 10.1002/chem.200390145.
The stereochemistries of heptacoordinate transition-metal complexes are analyzed by using continuous symmetry and shape measures of their coordination spheres. The distribution of heptacoordination through the transition-metal series is presented based on structural database searches including organometallic and Werner-type molecular complexes, metalloproteins, and extended solids. The most common polyhedron seems to be the pentagonal bipyramid, while different preferences are found for specific families of compounds, as in the complexes with three or four carbonyl or phosphine ligands, which prefer the capped octahedron or the capped trigonal prism rather than the pentagonal bipyramid. The symmetry maps for heptacoordination are presented and shown to be helpful for detecting stereochemical trends. The maximal symmetry interconversion pathways between the three most common polyhedra are defined in terms of symmetry constants and a large number of experimental structures are seen to fall along those paths.
通过使用七配位过渡金属配合物配位球的连续对称性和形状度量来分析其立体化学。基于包括有机金属和维尔纳型分子配合物、金属蛋白以及扩展固体在内的结构数据库搜索，呈现了整个过渡金属系列中七配位的分布情况。最常见的多面体似乎是五角双锥，而对于特定类别的化合物则发现了不同的偏好，例如在具有三个或四个羰基或膦配体的配合物中，它们更倾向于盖帽八面体或盖帽三棱柱而非五角双锥。给出了七配位的对称图，并表明其有助于检测立体化学趋势。根据对称常数定义了三种最常见多面体之间的最大对称相互转化途径，并且发现大量实验结构沿着这些途径分布。
