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1. A comparison of the chemical bonding and reactivity of Si 8 H 8 O 12 and Ge 8 H 8 O 12 : A theoretical study

   https://doi.org/10.1063/5.0046059  

   Muya, Jules Tshishimbi ; Donald, Kelling J. ; Ceulemans, Arnout ; Parish, Carol ( April 2021 , The Journal of Chemical Physics)
2. Structure and Bonding in [Sb@In 8 Sb 12 ] 3− and [Sb@In 8 Sb 12 ] 5−

   https://doi.org/10.1002/anie.201904109  

   Liu, Chao ; Tkachenko, Nikolay V. ; Popov, Ivan A. ; Fedik, Nikita ; Min, Xue ; Xu, Cong-Qiao ; Li, Jun ; McGrady, John E. ; Boldyrev, Alexander I. ; Sun, Zhong-Ming ( June 2019 , Angewandte Chemie International Edition)
3. Hydride Synthesis and Thermoelectric Properties of Type-I Clathrate K 8 E 8 Ge 38 (E = Al, Ga, In)

   https://doi.org/10.1021/acs.inorgchem.8b02977  

   Perez, Christopher J. ; Bates, Victor J. ; Kauzlarich, Susan M. ( January 2019 , Inorganic Chemistry)
4. Solvothermal Synthesis of [Cr 7 S 8 (en) 8 Cl 2 ]Cl 3  ⋅ 2H 2 O with Magnetically Frustrated [Cr 7 S 8 ] 5+ Double‐Cubes**

   https://doi.org/10.1002/chem.202103761  

   Gamage, Eranga H. ; Clark, Judith K. ; Yazback, Maher ; Cheng, Hai‐Ping ; Shatruk, Michael ; Kovnir, Kirill ( December 2021 , Chemistry – A European Journal)

   A novel transition metal chalcohalide [Cr₇S₈(en)₈Cl₂]Cl₃ ⋅ 2H₂O, with [Cr₇S₈]⁵⁺dicubane cationic clusters, has been synthesized by a low temperature solvothermal method, using dimethyl sulfoxide (DMSO) and ethylenediamine (en) solvents. Ethylenediamine ligand exhibits bi‐ and monodentate coordination modes; in the latter case ethylenediamine coordinates to Cr atoms of adjacent clusters, giving rise to a 2D polymeric structure. Although magnetic susceptibility shows no magnetic ordering down to 1.8 K, a highly negative Weiss constant,θ=−224(2) K, obtained from Curie‐Weiss fit of inverse susceptibility, suggests strong antiferromagnetic (AFM) interactions betweenS=3/2 Cr(III) centers. Due to the complexity of the system with (2S+1)⁷=16384 microstates from seven Cr³⁺centers, a simplified model with only two exchange constants was used for simulations. Density‐functional theory (DFT) calculations yielded the two exchange constants to beJ₁=−21.4 cm⁻¹andJ₂=−30.2 cm⁻¹, confirming competing AFM coupling between the shared Cr³⁺center and the peripheral Cr³⁺ions of the dicubane cluster. The best simulation of the experimental data was obtained withJ₁=−20.0 cm⁻¹andJ₂=−21.0 cm⁻¹, in agreement with the slightly stronger AFM exchange within the triangles of the peripheral Cr³⁺ions as compared to the AFM exchange between the central and peripheral Cr³⁺ions. This compound is proposed as a synthon towards magnetically frustrated systems assembled by linking dicubane transition metal‐chalcogenide clusters into polymeric networks.

    

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5. Chemically driven superstructural ordering leading to giant unit cells in unconventional clathrates Cs 8 Zn 18 Sb 28 and Cs 8 Cd 18 Sb 28

   https://doi.org/10.1039/D0SC03846F  

   Owens-Baird, Bryan ; Yox, Philip ; Lee, Shannon ; Carroll, Xian B. ; Grass Wang, Suyin ; Chen, Yu-Sheng ; Lebedev, Oleg I. ; Kovnir, Kirill ( September 2020 , Chemical Science)

   null (Ed.)

   The unconventional clathrates, Cs 8 Zn 18 Sb 28 and Cs 8 Cd 18 Sb 28 , were synthesized and reinvestigated. These clathrates exhibit unique and extensive superstructural ordering of the clathrate-I structure that was not initially reported. Cs 8 Cd 18 Sb 28 orders in the Ia 3̄ d space group (no. 230) with 8 times larger volume of the unit cell in which most framework atoms segregate into distinct Cd and Sb sites. The structure of Cs 8 Zn 18 Sb 28 is much more complicated, with an 18-fold increase of unit cell volume accompanied by significant reduction of symmetry down to P 2 (no. 3) monoclinic space group. This structure was revealed by a combination of synchrotron X-ray diffraction and electron microscopy techniques. A full solid solution, Cs 8 Zn 18−x Cd x Sb 28 , was also synthesized and characterized. These compounds follow Vegard's law in regard to their primitive unit cell sizes and melting points. Variable temperature in situ synchrotron powder X-ray diffraction was used to study the formation and melting of Cs 8 Zn 18 Sb 28 . Due to the heavy elements comprising clathrate framework and the complex structural ordering, the synthesized clathrates exhibit ultralow thermal conductivities, all under 0.8 W m −1 K −1 at room temperature. Cs 8 Zn 9 Cd 9 Sb 28 and Cs 8 Zn 4.5 Cd 13.5 Sb 28 both have total thermal conductivities of 0.49 W m −1 K −1 at room temperature, among the lowest reported for any clathrate. Cs 8 Zn 18 Sb 28 has typical p-type semiconducting charge transport properties, while the remaining clathrates show unusual n–p transitions or sharp increases of thermopower at low temperatures. Estimations of the bandgaps as activation energy for resistivity dependences show an anomalous widening and then shrinking of the bandgap with increasing Cd-content. 

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