Borreiche Boride als Modellstrukturen für die Elementmodifikationen des Bors

LiB12PC, the First Boron‐Rich Metal Boride with Phosphorus—Synthesis, Crystal Structure, Hardness, Spectroscopic Investigations

“…Exohedral BÀB bonds are between 1.689(4) and 1.749(3) (average 1.729 ), similar to those in LiB 12 PC. Exohedral B À C bond lengths are between 1.723(3) and 1.728 (3) , and the B À P distances are also nearly the same with 1.840(2) and www.chemeurj.org 1.859 (2) . Endohedral B À B bond lengths are between 1.759(2) and 1.847(3) , with a slightly higher average of 1.792 .…”

“…Colourless LiB 12 PC crystallizes orthorhombic in the space group Imma (No. 74) with a = 10.188(2) , b = 5.7689(11) , c = 8.127 (2) and Z = 4. Brown LiB 12 P 0.89 C 1.11 is very similar, but with a lower P content.…”

“…[3] A closer view on the structures of boron and boron-rich borides shows that there are three ways to solve the "problem of missing electrons"; that is, the formation of (condensed) boron polyhedra, additional electropositive metal atoms that are incorporated as cations and the uptake of more electronegative non-metal atoms with more valence electrons. [1,2] Little is known about phosphorous as an electron-donating non-metal in boron-rich borides. The only boron-rich phosphide known so far is the binary boron subphosphide with the ideal composition B 6 P, which has been well investigated due to its interesting properties for optoelectronic applications and as a refractory thermoelectric material.…”

“…[1] Boron-rich borides can serve as model compounds for elemental boron. [2] Furthermore they have interesting properties by themselves. [3] A closer view on the structures of boron and boron-rich borides shows that there are three ways to solve the "problem of missing electrons"; that is, the formation of (condensed) boron polyhedra, additional electropositive metal atoms that are incorporated as cations and the uptake of more electronegative non-metal atoms with more valence electrons.…”