The square antiprismatic configuration for the octacyanotungstate(IV) ion. The crystal structure of H₄W(CN)₈.6H₂O

Abstract

The crystal structure of the compound C8HI6N806W has been determined by means of a three-dimensional X-ray analysis. The space group is Pmma, and the cell demensions are a=14.30, b=9.881, c= 6-267/~, with 2 molecules per unit cell. The corresponding Mo compound is isomorphous with the W compound. The W(CN)~-anion has only mm symmetry and an approximate square antiprismatic

Vertical Ionization Energies and Electron Affinities of Ions in Solution from Outer-Sphere Charge Transfer Transition Energies

“…The internuclear distance, R, between two ion centers, r A + r D , is a variable parameter from one ion pair to another, but in most ion pairs considered here the close contact distance between the donor and acceptor centers is approximately the same (∼5.5-6 Å for ion pairs with two transition metal complexes, and ∼4.3-5 Å for [metal complex]X n (X -) halogen or pseudohalogen). [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] The exchange interaction term K AD falls off exponentially 30 and at the distance of an ion pair can be neglected; hence K AD ) 0 at large internuclear distances. In summary, both J AD and K AD can be neglected in the aqueous phase and (neglecting W) …”

Phase situation in solid tetramethylammonium octacyanotungstate

“…Octacyanometalates (IV,V) (M = Mo o r W) are known to show at least three defi?ite stereochemical arrangements: dodecahedra1 (HOARD et al;CORDEN et al;BASSON et al 1980 b), square antiprismatic (CHOJNACKI et al; BASSON et al 1970; and bicapped trigonal prismatic (BASSON et ale 1980 a ) . Recent studies on solid tetrabutylammonium octacyanotungstate (V) (CZERWONKA et al 1988) and tetrabutylammonium octacyanomolybdate (V) (CZERWONKA et al 1985) have revealed the existence of first-order phase transitions.…”

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.…”