Neutral and cationic tungsten(vi) fluoride complexes with tertiary phosphine and arsine coordination

Abstract

Reaction of WF6 with AsR3 (R = Me or Et) in anhydrous CH2Cl2 at low temperature forms the neutral seven-coordinate, [WF6(AsR3)] (R = Me, Et), the first arsine complexes of WF6, whilst o-C6H4(EMe2)2 (E = P, As) produces [WF4{o-C6H4(EMe2)2}2][WF7]2. Crystal structures show the latter contain dodecahedral cations, and present the highest oxidation state metal fluoride complexes known (and the highest possible for tungsten) with soft neutral phosphine and arsine coordination.

Synthesis, properties and structural features of molybdenum(v) oxide trichloride complexes with neutral chalcogenoether ligands

“…[30][31][32] The behaviour contrasts with that of o-C 6 H 4based group 15 ligands, where o-C 6 H 4 (PMe 2 ) 2 or o-C 6 H 4 (AsMe 2 ) 2 can produce seven-or eight-coordination in tungsten(VI) complexes, such as [WOCl 4 {o-C 6 H 4 (PMe 2 ) 2 }] or [WF 4 {o-C 6 H 4 (PMe 2 ) 2 } 2 ] 2+ . 45,46 The present work has also reported the first examples of Mo(V) telluroether complexes.…”

Stabilization of [WF5]+ by Bidentate N‐Donor Ligands

“…[6] There are few examples of cationic derivatives of transition-metal hexafluorides,which are prepared by the ligandinduced autoionization of WF 6 in the presence of bidentate Lewis bases (B')toform [WF 4 (B') 2 ] 2+ salts. [7][8][9] Similar Lewisacid behaviour towards bidentate Lewis bases is well documented for NbF 5 and TaF 5 . [10,11] Amonocationic derivative of at ransition-metal hexafluoride,[ MF 5 ] + ,o ri ts donor-stabilized derivatives have not been previously reported.…”

Stabilization of [WF5]+ by Bidentate N‐Donor Ligands

“…Communications tungsten centre and increased steric repulsion with respect to WF 6 .C omparisons to [WF 4 (2,2'-bipy) 2 ] 2+ (1.836(4) ) [8] and [WF 4 (P 2 Ar) 2 ] 2+ (1.91(4)-1.93(4) ;P 2 Ar = 1,2-bis(dimethylphosphino)benzene) reveal no appreciable differences in WÀFb ond lengths, [9] although these bonds are significantly elongated in the arsenic analogue [WF 4 (As 2 Ar) 2 ] 2+ (2.114(6) ). [9] TheW ÀNb onds,m eanwhile,a re similar to those of WF 6 (NC 5 H 5 )a nd its derivatives (ca. 2.25 ) [18] and [WF 4 (2,2'-bipy) 2 ] 2+ (2.263(7) ), [8] but much shorter than in WF 6 (NC 5 H 5 ) 2 (2.344(6) ).…”