Tertiary phosphine and arsine complexes of tungsten(IV)

Synthesis and Characterization of a Stable trans-Dioxo Tungsten(IV) Complex and Series of Mono-Oxo Molybdenum(IV) and Tungsten(IV) Complexes. Structural and Electronic Effects of π-Bonding in trans-[M(O)(X)(dppe)2]+/0 Systems

“…Trimethylsilyl azide was purchased (Fluka) and used as received. trans -W(PPh 3 ) 2 Cl 4 and Na 3 [Mo(HCOO) 6 ] were prepared by literature procedures. The syntheses of trans -[Mo(O)(F)(dppe) 2 ](BF 4 ) ( 1 ), trans -[Mo(O) 2 (dppe) 2 ]·2CH 3 OH ( 2 ), and trans -[Mo(O)(OH)(dppe) 2 ](ClO 4 ) ( 3 ) have been outlined in a previous communication; the details are given here.…”

A tungsten-mediated closed cycle of reactivity for the reduction of CO2 to CO

“…53 Treatment of [W IV OCl 2 (PMePh 2 ) 3 ] with anhydrous HCl(g) does indeed effect chloride-for-oxo exchange (Scheme 1) and remove the oxo ligand as H 2 O to produce the known compound trans-[WCl 4 (PMePh 2 ) 2 ], a species that is easily identified by its distinctive NMR spectrum. 27b, 28 We have also identified trans-[WCl 4 (PMePh 2 ) 2 ] by X-ray crystallography since its structure has a Data are for the P2 1 /n polymorph. b Average of two P-C aryl bond lengths.…”

Oxygen, sulphur, and selenium abstraction from WCl4Y (Y = O, S, or Se) by triphenylphosphine. Crystal and molecular structure of tetrachlorobis(triphenylphosphine)tungsten(IV)

“…This complex has been prepared previously by ligandexchange reactions on WC14*2NCPrn l3 and by reduction of WCI6 by zinc in the presence of PPh3.l4#l5 Attempts to prepare the complex directly from WCl, without reducing agents other than the phosphine were unsuccessfu1. 14 The i.r. spectra of the products were in accordance with that expected from the formulation WCI4*2PPh3 obtained by elemental analysis and showed no signs of unreacted WC14Y.…”