The Transition Products in Substitutional Photochemistry of [Mo(CN)8]4− – Theoretical Approach. X-ray Crystal Structure of (AsPh4)[W(bpy)(CN)6]

Abstract

The single crystal X-ray structure of (AsPh 4 )[W(bpy)(CN) 6 ] is described. The structure of octa-and hepta-coordinated intermediates of substitutional photolysis of [Mo(CN) 8 ] 4) ion in aqueous media were determined by performing semi-empirical calculations. On the basis of obtained results as well as on empirical data the photolysis scheme has been postulated.

Heptacoordinated W(IV) Cyanido Supramolecular Complex Trapped by Photolysis of a [W(CN)6(bpy)]2–/Zn2+ System

“…After bpy release, it is believed that the sequence of processes occur, depending on pH. This sequence is identical to that found in substitutional photolysis of octacyanidotungstate or, generally speaking, octacyanidometallates [M­(CN) 8 ] 4– (M = Mo or W) and leads to formation of penta- and tetra-cyanides of general formula [M­(CN) 5 O] 3– and [M­(CN) 4 O­(L)] n − (where L = O 2– , OH – or H 2 O depending on pH, n = 4, 3 or 2, respectively). − Only hexacoordinated complexes as penta- and tetra-cyanido complexes of Mo­(IV) and W­(IV) were isolated and characterized, including X-ray crystal structure determination. − The process of coordination number decrease from 8 to 6 is only postulated, and thus a theoretical approach was used to predict the formulas of formed intermediates . Both heptacyanido complexes of formula [M­(CN) 7 L] n − (where L = OH – , O 2– , n = 4, 5 respectively) and hexacyanido complexes of formula [M­(CN) 6 OL] n − (L = H 2 O, OH – or O 2– , n = 3–5) were postulated on the basis of spectral changes during photolysis.…”

“…In the case of [W­(CN) 6 (bpy)] 2– , the [W­(CN) 6 (OH) 2 ] 4– intermediate was postulated prior to pentacyanido complex formation . On the other hand, on the basis of theoretical calculations, the octacoordinated W­(IV) was excluded, and heptacoordinated hexacyanides were postulated . However, these calculations were based on the assumption that the reverse process, cyanation of [W­(CN) 5 O] 3– (cyanation product of [W­(CN) 4 OL] n − systems) to [W­(CN) 8 ] 4– , is a stepwise process through hexa- and hepta-cyanido intermediates with also a stepwise increase of the coordination number from 6 to 8.…”

Molecular magnetic materials based on 4d and 5d transition metals

“…106 The anion [W V (2,2 0 -bipy)(CN) 6 ] À , which contains six cyanide ligands but is eight coordinate due to the additional 2,2 0 -bipy ligand, was first reported and characterized as the (Ph 4 As)[W V (2,2 0 -bipy)(CN) 6 ] salt. 107,108 The W V center is in a d 1 configuration with a spin S = 1 2 . Since 2005, the Hong group has used the anion building unit for mixed metal magnetic assemblies.…”

Magnetism in Heterobimetallic and Heterotrimetallic Chains Based on the Use of [WV(bipy)(CN)6]– as a Metalloligand

“…Materials: The chemicals and solvents used were of reagent grade and they were purchased from commercial sources. The starting compounds [Cu II Mn II L](ClO 4 ) 2 · H 2 O · MeOH,, and AsPh 4 [W(bipy)(CN) 6 ], were synthesized by following the literature procedures (AsPh 4 + = tetraphenylarsonium cation).…”

“…Materials: The chemicals and solvents used were of reagent grade and they were purchased from commercial sources. The starting compounds [Cu II Mn II L](ClO 4 ) 2 ·H 2 O·MeOH, [81,82] and AsPh 4 [W(bipy)-(CN) 6 ] [99,100] were synthesized by following the literature procedures (AsPh 4 + = tetraphenylarsonium cation Physical Measurements: Elemental analyses (C, H, N) were performed with a Perkin-Elmer 2400 analyzer. IR spectra were recorded with a FTIR Bruker Tensor V-37 spectrophotometer using KBr pellets in the range 4000-400 cm -1 .…”