The synthesis and reactions of the novel bis(diphenylacetylene) complex [WI 2(NCMe) 2(η 2-PhC 2Ph) 2

Abstract

The mono(acetonitrile) compound [WI 2(CO)(NCMe)(η 2-PhC 2Ph) 2] reacts in refluxing acetonitrile for 5 h in the presence of PhC 2Ph to give the bis(acetonitrile) compound [WI 2(NCMe) 2(η 2-PhC 2Ph) 2] ( 1) in high yield. Refluxing 1 in CHCl 3 for 3 h affords the iodobridged dimer [W(μ-I)I(NCMe)(η 2-PhC 2Ph) 2] 2 ( 2). Compound 1 reacts with one equivalent and three equivalents of PPh 3 to give [WI 2(NCMe)(PPh 3)(η 2-PhC 2Ph) 2] ( 3) and [WI 2(PPh 3) 3 (η 2-PhC 2Ph)] ( 4), respectively. Equimolar quantities of 1 and Ph 2P(CH 2) n PPh 2 ( n = 1–3) react in CH 2Cl 2 at room temperature to give the acetonitrile displaced products [WI 2{Ph 2P(CH 2) n PPh 2}(η 2-PhC 2Ph) 2] ( 5–7). Reaction of 1 with an equimolar amount of Na[S 2CX] (X = NMe 2 or NEt 2) in CH 2Cl 2/MeOH 50:50 gives the iodo-bridged dimers [W(μ-I)(S 2CX)(η 2-PhC 2Ph) 2] 2 ( 8 and 9). Two equivalents of Na[S 2CX] (X = NMe 2 or NEt 2) react in CH 2Cl 2/MeOH 50:50 at room temperature to afford the bis(dithiocarbamate) compounds [W(S 2CX) 2(η 2-PhC 2Ph) 2] ( 10 and 11). 13C NMR spectroscopy suggests that the two diphenylacetylene ligands in [W(S 2CX) 2(η 2-PhC 2Ph) 2] are donating a total of six electrons to the metal.