研究和评论:材料科学杂雷竞技苹果下载志》上
菜单ISSN: 2321 - 6212
ISSN: 2321 - 6212
乔治窝
康科迪亚大学,加拿大
主题:启J垫。Sci >
DOI:10.4172 / 2321 - 6212 c8 - 034
晶体学无疑是最强大的方法获得结构数据结晶固体。然而,有些情况下,即使是最强大的方法,也可以受益于技术的帮助不用于结构的决心。在当前工作,119 sn穆斯堡尔谱学是用来帮助晶体学,寻找锡(II)位置在单位细胞并确定锡(II)与衍射数据的协调一致和锡电子结构。第一种情况将显示,即使是高质量的单晶数据并不总是保证正确的解决方案。第一次尝试的结构α−SnF2产生锡位置很合理R和Rw残差,0.23 - -0.25。然而,氟原子的位置不能被发现。经过很多努力,完整的晶体结构终于解决了14年后。锡的位置之间的差异两个解决方案是,在后者中,一半的锡原子是特殊的网站;然而,锡亚点阵是相同的。因为锡网站在最初的解决方案给了非常合理的残差,14年的努力都白费了。 The presentation will show that this could have been avoided using 119Sn Mossbauer spectroscopy. This was possible since the spectrum had already been recorded. It will also be shown how Mossbauer spectroscopy can help determine the tin coordination, when combined with powder diffraction data, in the case of disordered structures. The presence of tin(II), disordered with a metal ion in cubic coordination, when diffraction shows there is no lattice distortion and no superstructure, suggests that tin has also a cubic coordination. This would require the tin lone pair to be non-stereo active; however, Mossbauer spectroscopy shows it is stereo active. The same technique helps to suggest an alternate disordered structure in agreement with the X-ray powder diffraction data. Furthermore, 119Sn Mossbauer spectroscopy was also used to assist diffraction for solving the crystal structure of a compound suffering from an extreme case of preferred orientation. The presentation will show the hurdles faced by diffraction methods alone and how we designed the use of Mossbauer spectroscopy in order to rescue crystallography.
乔治窝是一个部门的化学和生物化学教授康科迪亚大学,加拿大。他已经完成了他的博士学位在大学德雷恩1。他的研究兴趣是固体无机化学。他一直教学普通化学、无机化学(主要组)和他在各种期刊上发表文章。
电子邮件:(电子邮件保护)
