Synthesis and reactions of the dichloro bis(3-hexyne) complex [WCl2(CO)(NCMe)(η2-EtC2Et)2]

Reaction of [WCl2(CO)3(NCMe)2] (prepared in situ by reacting [WI2(CO)3(NCMe)2] with two equivalents of NaCl in acetone) with an excess of EtC2Et in CH2Cl2 gives the bis(3-hexyne) complex [WCl2(CO)(NCMe)(η2-EtC2Et)2] (1). Equimolar quantities of 1 and L {L=NPh3, PPh3, LMo or LW [MI2(CO)3{MeC(CH2PPh2)3-P,P′}] (M=Mo, LMo; W, LW)} react in CH2Cl2 to give the acetonitrile replaced products, [WCl2(CO)L(η2-EtC2Et)2] (2→5), in good yield. Reaction of 1 with L2 {L=PPh3, LMo, LW, L2=Ph2P(CH2)nPPh2 (1,3,4,6), cis-Ph2PCHCHPPh2} in CH2Cl2 at room temperature afforded the mono(3-hexyne) complexes, [WCl2(CO)L2(η2-EtC2Et)] (6–13). Treatment of 1 with two equivalents of P(OR)3 {R=Et, iPr} in diethyl ether gives [WCl2(CO){P(OR)3}2(η2-EtC2Et)] (14 and 15), respectively. Equimolar amounts of 1 and 2,2′- bipyridyl (bipy) yields the cationic complex [WCl(CO)(bipy)(η2-EtC2Et)2]Cl (16). Reaction of equimolar quantities of 1 and NaS2CNR2·3H2O (R=Me, Et) in CH2Cl2 at room temperature affords the mono-chloro complexes [WCl(CO)(S2CNR2)(η2-EtC2Et)2] (17 and 18).