More Like this

1. The Synthesis and Crystal Structure of Six Quaternary Lithium-Alkaline Earth Metal Alumo-Silicides and Alumo-Germanides, A2LiAlTt2 (A = Mg, Ca, Sr, Ba; Tt = Si, Ge)

   https://doi.org/10.3390/inorganics11090351  

   Kontomaris, Paraskevi ; Darone, Gregory M. ; Paredes-Quevedo, Laura C. ; Bobev, Svilen ( September 2023 , Inorganics)

   Reported are the synthesis and structural characterization of a series of quaternary lithium-alkaline earth metal alumo-silicides and alumo-germanides with the base formula A2LiAlTt2 (A = Ca, Sr, Ba; Tt = Si, Ge). To synthesize each compound, a mixture of the elements with the desired stoichiometric ratio was loaded into a niobium tube, arc welded shut, enclosed in a silica tube under vacuum, and heated in a tube furnace. Each sample was analyzed by powder and single-crystal X-ray diffraction, and the crystal structure of each compound was confirmed and refined from single-crystal X-ray diffraction data. The structures, despite the identical chemical formulae, are different, largely dependent on the nature of the alkaline earth metal. The differing cation determines the structure type—the calcium compounds are part of the TiNiSi family with the Pnma space group, the strontium compounds are isostructural with Na2LiAlP2 with the Cmce space group, and the barium compounds crystallize with the PbFCl structure type in the P4/nmm space group. The anion (silicon or germanium) only impacts the size of the unit cell, with the silicides having smaller unit cell volumes than the germanides.

    

   more » « less
2. Dibridged, Monobridged, Vinylidene-Like, and Linear Structures for the Alkaline Earth Dihydrides Be 2 H 2 , Mg 2 H 2 , Ca 2 H 2 , Sr 2 H 2 , and Ba 2 H 2 . Proposals for Observations

   https://doi.org/10.1021/acs.inorgchem.0c01651  

   Narendrapurapu, Beulah S. ; Bowman, Michael C. ; Xie, Yaoming ; Schaefer, Henry F. ; Tkachenko, Nikolay V. ; Boldyrev, Alexander I. ; Li, Guoliang ( August 2020 , Inorganic Chemistry)
3. Layered Quaternary Germanides—Synthesis and Crystal and Electronic Structures of AE Li 2 In 2 Ge 2 ( AE = Sr, Ba, Eu)

   https://doi.org/10.1021/acs.inorgchem.9b00588  

   Ovchinnikov, Alexander ; Bobev, Svilen ( May 2019 , Inorganic Chemistry)
4. Lithium metal atoms fill vacancies in the germanium network of a type-I clathrate: synthesis and structural characterization of Ba 8 Li 5 Ge 41

   https://doi.org/10.1039/D3DT01168B  

   Ghosh, Kowsik ; Ovchinnikov, Alexander ; Baitinger, Michael ; Krnel, Mitja ; Burkhardt, Ulrich ; Grin, Yuri ; Bobev, Svilen ( August 2023 , Dalton Transactions)

   Clathrate phases with crystal structures exhibiting complex disorder have been the subject of many prior studies. Here we report syntheses, crystal and electronic structure, and chemical bonding analysis of a Li-substituted Ge-based clathrate phase with the refined chemical formula Ba8Li5.0(1)Ge41.0, which is a rare example of ternary clathrate-I where alkali metal atoms substitute framework Ge atoms. Two different synthesis methods to grow single crystals of the new clathrate phase are presented, in addition to the classical approach towards polycrystalline materials by combining pure elements in desired stoichiometric ratios. Structure elucidations for samples from different batches were carried out by single-crystal and powder X-ray diffraction methods. The ternary Ba8Li5.0(1)Ge41.0 phase crystallizes in the cubic type-I clathrate structure (space group no. 223, a  10.80 Å), with the unit cell being substantially larger compared to the binary phase Ba8Ge43 (Ba8□3Ge43, a  10.63 Å). The expansion of the unit cell is the result of the Li atoms filling vacancies and substituting atoms in the Ge framework, with Li and Ge co-occupying one crystallographic (6c) site. As such, the Li atoms are situated in four-fold coordination environment surrounded by equidistant Ge atoms. Analysis of chemical bonding applying the electron density/ electron localizability approach reveals ionic interaction of barium with the Li–Ge framework, while the lithium-germanium bonds are strongly polar covalent. 

   more » « less
5. Mechanochemical Synthesis of Ca- and Mg-Double Salt Crystalline Materials Using Insoluble Alkaline Earth Metal Bearing Minerals

   https://doi.org/10.1021/acssuschemeng.8b06129  

   Sharma, Lohit ; Kiani, Daniyal ; Honer, Kenneth ; Baltrusaitis, Jonas ( March 2019 , ACS Sustainable Chemistry & Engineering)