DOE OSTI2020
Cr(Na2C3N3O5)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of two chromium molecules and one Na2C3N3O5 framework. In the Na2C3N3O5 framework, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to two equivalent N+1.67- and four O2- atoms to form distorted edge-sharing NaN2O4 octahedra. There are one shorter (2.57 Å) and one longer (2.63 Å) Na–N bond lengths. There are a spread of Na–O bond distances ranging from 2.34–2.83 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to two N+1.67- and four O2- atoms. There are one shorter (2.37 Å) and one longer (2.58 Å) Na–N bond lengths. There are a spread of Na–O bond distances ranging from 2.37–2.81 Å. There are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a single-bond geometry to one N+1.67- atom. The C–N bond length is 1.18 Å. In the second C4+ site, C4+ is bonded in a single-bond geometry to one N+1.67- atom. The C–N bond length is 1.18 Å. In the third C4+ site, C4+ is bonded in a single-bond geometry to one N+1.67- atom. The C–N bond length is 1.17 Å. There are three inequivalent N+1.67- sites. In the first N+1.67- site, N+1.67- is bonded in a distorted single-bond geometry to one C4+ and one O2- atom. The N–O bond length is 2.34 Å. In the second N+1.67- site, N+1.67- is bonded in a distorted trigonal planar geometry to one Na1+, one C4+, and one O2- atom. The N–O bond length is 2.13 Å. In the third N+1.67- site, N+1.67- is bonded in a 1-coordinate geometry to three Na1+ and one C4+ atom. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Na1+ and one N+1.67- atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and one O2- atom. The O–O bond length is 1.24 Å. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Na1+ and one O2- atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and one N+1.67- atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ atoms.