The reversible hydrogenation of BiPd3 followed by in situ methods and the crystal structure of PbPd3D0.13(1)

From Metallic LnTt (Ln = La, Nd; Tt = Si, Ge, Sn) to Electron‐precise Zintl Phase Hydrides LnTtH

“…It plays an important role in compounds A 5 Pn 3 ( A = Ca, Yb, Sm, Eu; Pn = Sb, Bi), some of which are in fact ternary hydrides A 5 Pn 3 H . Further examples include structural change upon hydrogenation like (i) from cubic to hexagonal close packing for heavier lanthanides for the reaction Ln H 2 + ½H 2 → Ln H 3 , (ii) from a crystal structure related to the double‐hexagonal close packing to one related to a cubic close packing (ccp) or between different ccp related structures in palladium‐rich intermetallics, or (iii) from a TiNiSi to the ZrNiAl or to the ZrBeSi type of structure in compounds Ln NiSn , . The structure‐directing effect of hydrogen is also at work in order‐disorder transitions in complex transition metal hydrides and Laves phase hydrides, where the driving force for the transition is the minimization of repulsive H–H interactions …”

Synthesis and Crystal Structure of SnPd3D0.138(7) by Neutron Powder Diffraction

“…The crystal structure was refined based on neutron powder diffraction, yielding the composition SnPd 3 D 0.138(7) (Figure and Table ). The hydrogen content of SnPd 3 is comparable to PbPd 3 (0.13 hydrogen per formula unit) . The interatomic Pd–D distances of both deuterides are also similar [SnPd 3 D 0.138(7) : d (Pd–D) = 199.169(6) pm, PbPd 3 D 0.13(1) : d (Pd–D) = 202.016(3) pm], and in the typical range of metallic palladium‐rich deuterides .…”

“…Hydrogen atoms occupy 13 % of octahedral holes in a statistical manner, resulting in a composition PbPd 3 H 0.13 , . This behavior is typical for M Pd 3 compounds, which form hydrides structurally related to the cubic close packing ( M = Mg, In, Tl, Pb, Bi). Often, hydrogen‐induced rearrangements take place, from one superstructure of the cubic close packing, e.g.…”

“…In the case of PbPd 3 , the volume increase is slightly larger, at 0.6 %, and the crystal structure is of the cubic anti‐perovskite type [ Pm 3 m, a = 404.033(6) pm for the deuteride]. Hydrogen atoms occupy 13 % of octahedral holes in a statistical manner, resulting in a composition PbPd 3 H 0.13 , . This behavior is typical for M Pd 3 compounds, which form hydrides structurally related to the cubic close packing ( M = Mg, In, Tl, Pb, Bi).…”

In Situ Hydrogenation and Crystal Chemistry Studies of Co2Si Type Compounds MgPd2 and Pd2Zn

“…This is caused by the incorporation of deuterium and its space requirements. The D–Mg distances [ d = 2.226(8)–2.271(5) Å] are comparable to 1.901(8)–2.29(2) Å in MgPd 3 D x and the D–Pd distances [ d = 1.837(5)–2.106(5) Å] are typical for palladium‐rich hydrides, like 1.97(2)–1.999(1) Å in MgPd 3 D 0.79 , 2.0113(1) Å in InPd 3 D 0.89 , or 2.000(3)–2.02363(6) Å in BiPd 3 D 0.23 . The interatomic deuterium–deuterium distances are greater than 3 Å and also somewhat greater than those in neighboring [MgPd 5 ] octahedral voids in MgPd 3 D 0.94 (2.858 Å) …”