Metal borides¹ are inorganic solids that often show refractory properties, like super-­hardness² and very high-­melting points. They may also prove to be exciting concerning their electronic structure, as  shown for super-‐conducting magnesium diboride,  MgB₂,³ or samarium hexaboride,  SmB₆,⁴ which was recently described to be a topological insulator.

New investigations on nanoscale and bulk mono‐, di-tetra-­, and hexaborides will be  presented. Examples  are  MnB₄,  crystallizing  similar  to  hypothetical  tetragonal  diamond  but  exhibiting  an unexpected Peierls distortion,^5,6 solid solutions of (M,M')B₆ with good  thermoelectric  properties,⁷ and nanoscale metal borides that can be (ferro)magnetic.⁸ Synthesis,  characterization, structures, and properties will be discussed. 

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  Seshadri, B. Albert, Angew. Chem. 126 (2014) 1710-­1714, Int. Ed. Engl. 53 (2014) 1684-­1688

6 A. Knappschneider, C. Litterscheid, J. Brgoch, N. C. George, S. Henke, A. K. Cheetham, J. G. Hu, R. 

  Seshadri, B. Albert, Chem. Eur. J. 21 (2015), 8177-­8181 

7 M. Gürsoy, M. Takeda, and B. Albert, J. Solid State Chem. 221 (2015) 191-­195

8 S. Rades, S. Kraemer, R. Seshadri, B. Albert, Chem. Mater. (2014) 1549-­1552