Refinement of the crystal structure of potassium octacyanomolybdate(IV) dihydrate

Abstract

X-ray diffraction on single crystal was used to refine the crystal structure of K 4 [Mo(CN) 8 ]⋅ ⋅ ⋅ ⋅2H 2 O. For the first time the positions of all hydrogen atoms in the complex were localized, the crystal structure being determined at temperature 173 K. The compound crystallizes in the orthorhombic system, space group Pnma, cell parameters a = 16.6959(10), b = 11.6090(6) and c = 8.6796(6) Å, V = 1682.30(18) Å 3 , Z = 4, D X = 1.961 g•cm-3 , number of independent reflections 2365, reliability factors R = 0.0329, wR = 0.0590. The coordination polyhedron of the molybdenum atoms is a dodecahedron [Mo(CN) 8 ]. The potassium atoms have three different deformed polyhedra: trigonal bipyramid [K1N 4 OH 2 ], tetragonal pyramid [K2N 5 ] and trigonal prism with one additional atom [K3N 5 (OH 2) 2 ]. All cyanogroups in the complex are terminal.

Structural and Vibrational Studies of Sr2[W(CN)8]·10H2O

“…The influence of the nature of outer cation in the rangeH + –Na + –K + –NH 4 + –Rb + –Sr 2+ on the structure of octacyanometallates [ M (CN) 8 ] 4– ( M = W, Mo) is strong. The complex anion [ M (CN) 8 ] 4– in the structure of H 4 [W(CN) 8 ] · 6H 2 O2 has trigonal anti ‐prismatic coordination, in the structure of Na 3 H 3 O[W(CN) 8 ] · 4H 2 O,3 K 4 [W(CN) 8 ] · 2H 2 O,4 K 4 [Mo(CN) 8 ] · 2H 2 O,5,6 Rb 4 [W(CN) 8 ] · 2H 2 O,7 Rb 4 [Mo(CN) 8 ] · 3H 2 O8 – dodecahedral. In the structure of (NH 4 ) 4 [Mo(CN) 8 ] · 0.5H 2 O8 one anion has trigonal anti ‐prismatic coordination, second one – dodecahedral.…”