Tetraphenylphosphonium octahydrotriborate

Abstract

The structure of the title salt, C24H20P+·H8B3 −, at 120 (2) K has triclinic (P1) symmetry with an unusual Z = 5, although there is pseudosymmetry observed with the tetraphenylphosphonium cations exhibiting I symmetry. One of the anions is disordered over two sets of sites with refined occupancies of 0.478 (11) and 0.522 (11).

Synthesis and Single Crystal Structure of Sodium Octahydrotriborate, NaB3H8

“…The B 3 H 8 anion (Figure ) straddles a crystallographic mirror plane that is perpendicular to the a -axis; the sodium atom and boron atom B2 (and the H atoms attached to B2) reside in this plane. As seen for other B 3 H 8 compounds, ,,− the three boron atoms form almost a perfect equilateral triangle with B(1)–B(2) = 1.790(1) Å and B(1)–B(1A) = 1.798(2) Å. Each boron bears two terminal hydrogen atoms with B(1)–H(11) = 1.08(2) Å, B(1)–H(12) = 1.10(1) Å, and B(2)–H(21) = 1.06(2) Å.…”

Identifying and characterizing translationally modulated molecular crystal structures

“…A structure that seems to have a too-high Z 0 value may still have a real pseudotranslation. Consider KUTCUY (Beckett et al, 2010). PLATON (Spek, 2009) recommends a change from P1, Z 0 = 5 to I 4 4, Z 0 = 1.25 but in the tetragonal cell there would still be an n = 5 pseudotranslation consisting of four symmetryrelated molecules on general positions and one molecule on a 4 4 site (n_ind = 2).…”