Room temperature X-ray diffraction pattern of the [N(CH3)4]2-
CoCl2Br2 compound is shown in Fig. 1. All the reflection peaks were
indexed in the orthorhombic symmetry with Pnma space group. The
lattice parameters of the selected unit cell were refined using the
least-squares sub-routine of a standard computer program. These
refined lattice parameters are a = 12.384(2) Å, b = 9.058(2) Å,
c = 15.647(3) Å and V = 1755.190(4) Å3 with estimated standard
deviation in parenthesis. The compound structure is isotype to
[N(CH3)4]2CoCl4, and [N(CH3)4]2CoBr4 [13,14]. In the [N(CH3)4]2-
CoCl4xBrx series (x = 0, 2 and 4), we can correlate the volume per
unit molecular formula of these materials with x (Table 1). The
volume v is found to augment with increasing x.
The crystal structure consists of alternate organic–inorganic
½ðNðCH3Þ4Þþ=CoX2
4 (X = Cl or Br) layers and organic sheets
(N(CH3)4)+. Organic and inorganic groups are not disordered. Its
main geometrical features are those commonly observed in the
atomic arrangements of [N(CH3)4]2CoCl4 and [N(CH3)4]2CoBr4