DOE OSTI2020
CrH6(NBr2)2CrH12(N2Br)2 is Protactinium-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one CrH12(N2Br)2 cluster and one CrH6(NBr2)2 cluster. In the CrH12(N2Br)2 cluster, Cr3+ is bonded in an octahedral geometry to four N3- and two equivalent Br1- atoms. There are two shorter (2.13 Å) and two longer (2.14 Å) Cr–N bond lengths. Both Cr–Br bond lengths are 2.49 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Cr3+ and three H1+ atoms. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. In the second N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Cr3+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. Br1- is bonded in a single-bond geometry to one Cr3+ atom. In the CrH6(NBr2)2 cluster, Cr3+ is bonded in an octahedral geometry to two equivalent N3- and four Br1- atoms. Both Cr–N bond lengths are 2.12 Å. There are two shorter (2.51 Å) and two longer (2.53 Å) Cr–Br bond lengths. N3- is bonded to one Cr3+ and three H1+ atoms to form distorted corner-sharing NCrH3 tetrahedra. There is one shorter (1.02 Å) and two longer (1.03 Å) N–H bond length. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a single-bond geometry to one Cr3+ atom. In the second Br1- site, Br1- is bonded in a single-bond geometry to one Cr3+ atom.