Barium Thiocyanate Trihydrate

Article abstract of DOI:10.1107/S0567740882003033

Ba(SCN)2*3H2O, M_r = 307.55, is monoclinic, C2/m, with a = 15.981(1), b = 4.441(1), c = 13.333(1) Angstroem, β = 104.65(1)^o, V = 915.5 Angstroem³, Z = 4, D_c = 2.23 Mg m^-3, μ(Mo Kα) = 4.74 mm^-1.The salt, which was reported in a previous structural study as a dihydrate , is actually a trihydrate.The third water molecule has been located and the structure has been refined to R = 0.032 for 1059 observed reflections.Ba has a tricapped trigonal prismatic coordination: four N, four O and one S (Ba-N = 2.90-2.91, Ba-O = 2.71-2.90, Ba-S = 3.39 Angstroem).Bond lengths within the two independent thiocyanate groups are N-C = 1.15 and C-S = 1.65-1.66 Angstroem.The water molecules are involved in O-H...S hydrogen bonds with O...S = 3.36-3.77 Angstroem.E.s.d.'s for distances involving nonhydrogen atoms are A reversible phase transition was found to occur at about 135 K by Raman spectroscopy.