Ståhl Kenny, Andersen Jens E T, Shim Irene, Christgau Stephan
Chemistry Department, Technical University of Denmark, Building 207, DK-2800 Lyngby, Denmark.
Acta Crystallogr B. 2009 Aug;65(Pt 4):481-7. doi: 10.1107/S0108768109023489. Epub 2009 Jul 16.
The crystal structures of strontium diformate in space groups P2(1)2(1)2(1) (alpha form, 295 K), P4(1)2(1)2 (beta form, 334 and 540 K) and I4(1)/amd (delta form, 605 K), and strontium fumarate in space groups Fddd (beta form, 105 K) and I4(1)/amd (alpha form, 293 K) have been determined from synchrotron X-ray powder diffraction data. Except for the alpha-strontium diformate, all the structures are based on a diamond-like Sr-ion arrangement, as in strontium acetylene dicarboxylate. The formate ions are disordered in the delta phase owing to steric hindrance. The fumarate ions are disordered over four (alpha) or two (beta) symmetry-equivalent orientations. alpha-Strontium fumarate crystallizes with a unique 90 degree carboxylate dihedral angle, and is stable up to 773 K.
已根据同步加速器X射线粉末衍射数据确定了甲酸锶在空间群P2(1)2(1)2(1)（α型，295K）、P4(1)2(1)2（β型，334和540K）和I4(1)/amd（δ型，605K）中的晶体结构，以及富马酸锶在空间群Fddd（β型，105K）和I4(1)/amd（α型，293K）中的晶体结构。除α-甲酸锶外，所有结构均基于类似金刚石的锶离子排列，如乙炔二羧酸锶中的排列。由于空间位阻，甲酸根离子在δ相中无序排列。富马酸根离子在四个（α型）或两个（β型）对称等效取向上无序排列。α-富马酸锶以独特的90度羧基二面角结晶，并且在高达773K时稳定。
