The synthesis and reactions of the novel bis(diphenylacetylene) complex [WI2(NCMe)2(η2-PhC2Ph)2]

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