Monodentately coordinated o-phenylenediacetonitrile seven-coordinate complexes of molybdenum(II) and tungsten(II): X-ray crystal structure of [WI 2(CO) 3{1,2-C 6H 4(CH 2CN) 2- N} 2

Abstract

Treatment of [MI 2(CO) 3(NCMe) 2] (M=Mo or W) with 2 equiv. of o-phenylenediacetonitrile (1,2-C 6H 4(CH 2CN) 2) gives the complexes [MI 2(CO) 3{1,2-C 6H 4(CH 2CN) 2- N} 2] ( 1 and 2) via displacement of the acetonitrile ligands. The tungsten complex [WI 2(CO) 3{1,2-C 6H 4(CH 2CN) 2- N} 2] ( 2) has been characterised crystallographically. The geometry surrounding the coordination sphere is capped octahedral with a carbonyl group in the unique capping position, an iodide and two carbonyls in the capped face and an iodide and two nitrogen atoms from nitrile groups in the uncapped face. Reactions of 1 and 2 with equimolar amounts of L (L=PPh 3, AsPh 3, SbPh 3, P(OPh) 3) affords [MI 2(CO) 3(NCMe)L], which followed by an in situ reaction with 1 equiv. of 1,2-C 6H 4(CH 2CN) 2 gives the new mixed ligand complexes [MI 2(CO) 3{1,2-C 6H 4(CH 2CN) 2- N}L] ( 3– 10) in high yield. Reaction of [MI 2(CO) 3(NCMe) 2] and [MI 2(CO) 3(NCMe)(PPh 3)] with 2 and 1 equiv. of L 1 (L 1=[WI 2(CO) 3{1,2-C 6H 4(CH 2CN) 2- N} 2] ( 2)) gives the first trimetallic [MI 2(CO) 3L 1 2] ( 11 and 12) and bimetallic [MI 2(CO) 3L 1(PPh 3)] ( 13 and 14) o-phenylene diacetonitrile bridged complexes in high yield.