2,2′:6′,2"-terpyridine complexes of molybdenum(II) and tungsten(II).: X-ray crystal structures of [MoI(CO)(terpy)(η2-PhC2Ph)]I and [WI(terpy)(η2-PhC2Ph)2]I•CDCl3

Equimolar quantities of [MI2(CO)(3)(NCMe)(2)] (M = Mo or W) and terpy (terpy = 2,2':6',2 "-terpyridine) react in CH2Cl2 at room temperature to give the cationic complexes [MI(CO)(3)(terpy)]I (1 and 2) in high yield. Treatment of [MoCl(GeCl3)(CO)(3)(NCMe)(PPh3)] with one equivalent of terpy affords [Mo(GeCl3)(CO)(2)(PPh3)(terpy)]Cl (3) in good yield. Reaction of [MI2(CO)(NCMe)(eta(2)-RC2R)(2)](M = Mo, W; R = fh; for M = W only, R = Me) with an equimolar quantity of terpy in CH,CI, at room temperature gives the cationic complexes [MI(CO)(terpy)(eta(2)-RC2R)]I (4 and 5) or the crystallographically characterised cationic complex [WI(terpy)(eta(2)-PhC2Ph2)]I (6). Equimolar quantities of [WI(CO)(terpy)(eta(2)-MeC2Me)]I(5) and Na[BPh4] react to give the anion-exchanged product, [WI(CO)(terpy)(eta(2)-MeC2Me)][BPh4] (7). The X-ray crystal structure of [MoI(Co)(terpy)(eta(2)-PhC2Ph)]I shows the three nitrogen atoms of the terpy bonded in the equatorial plane of an octahedron together with the carbonyl group. The iodo and diphenylacetylene ligands are mutually trans- to each other in the axial positions. The structure of [WI(terpy)(eta(2)-PhC2Ph2)(2)]I . CDCl3 (6) has a distorted octahedral geometry, with the three nitrogen atoms of the terpy ligand in a mer-configuration, with two cis-and parallel diphenylacetylene ligands and an iodo group occupying the other three mer-sites. (C) 2000 Elsevier Science S.A. All rights reserved.