Todorov Iliya, Sevov Slavi C
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Inorg Chem. 2005 Jul 25;44(15):5361-9. doi: 10.1021/ic050803t.
The title compounds were synthesized from the elements by heating the corresponding mixtures at high temperature. Their structures were determined from single-crystal X-ray diffraction. Li(9)(-)(x)()EuSn(6+)(x)(), Li(9)(-)(x)()CaSn(6+)(x)(), Li(5)Ca(7)Sn(11), and Li(6)Eu(5)Sn(9) contain columns of stacked aromatic pentagons of Sn(5)(6)(-) that are analogous to the cyclopentadienyl anion C(5)H(5)(-). The pentagons are separated with Ca(2+) or Eu(2+) in the columns and resemble a polymeric metallocene. In addition to the columns, the isostructural Li(9)(-)(x)()EuSn(6+)(x)() and Li(9)(-)(x)()CaSn(6+)(x)() contain isolated tin atoms and bent tin trimers while Li(5)Ca(7)Sn(11) and Li(6)Eu(5)Sn(9) contain flat zigzag hexamers and flat zigzag infinite chains of tin, respectively. The isostructural LiMgEu(2)Sn(3) and LiMgSr(2)Sn(3) do not contain columns of pentagons but only flat zigzag infinite chains of tin. The aromaticity of the pentagons and the conjugation of the pi-systems of the hexamers and the infinite chains are discussed. The title compounds are also characterized by magnetic and conductivity measurements.
通过在高温下加热相应的混合物，由元素合成了标题化合物。它们的结构通过单晶X射线衍射确定。Li(9)(-)(x)()EuSn(6+)(x)()、Li(9)(-)(x)()CaSn(6+)(x)()、Li(5)Ca(7)Sn(11)和Li(6)Eu(5)Sn(9)包含由Sn(5)(6)(-)堆叠的芳香五边形柱，类似于环戊二烯基阴离子C(5)H(5)(-)。五边形在柱中被Ca(2+)或Eu(2+)隔开，类似于聚合金属茂。除了柱之外，同构的Li(9)(-)(x)()EuSn(6+)(x)()和Li(9)(-)(x)()CaSn(6+)(x)()还包含孤立的锡原子和弯曲的锡三聚体，而Li(5)Ca(7)Sn(11)和Li(6)Eu(5)Sn(9)分别包含扁平的锯齿形六聚体和扁平的锯齿形锡无限链。同构的LiMgEu(2)Sn(3)和LiMgSr(2)Sn(3)不包含五边形柱，只包含扁平的锯齿形锡无限链。讨论了五边形的芳香性以及六聚体和无限链的π体系的共轭。标题化合物还通过磁性和电导率测量进行了表征。
