SYNTHESES AND NMR-SPECTRA OF CO3(CO)9[MU-3-CCHAR2] CLUSTERS DERIVED FROM DDT AND RELATED MOLECULES - X-RAY CRYSTAL-STRUCTURES OF [[BIS(4-CHLOROPHENYL)METHYL]CARBYNYL]TRICOBALT NONACARBONYL AND OF ITS BIS(4-CHLORONAPHTHYL) ANALOG

The reaction of Co2(CO)8 with a series of l,l,l-trichloro-2,2-bis(aryl)ethanes yields the corresponding Co3(CO)9[μ3-CCHAr2] tetrahedral clusters, where Ar = 4-chlorophenyl (3), 4-methoxyphenyl (4), or 4-chloronaphthyl (6). CO3(CO)9[μ3-CCH(P-C6H4Cl)2] (3) crystallizes in the monoclinic space group P21/n with α = 13.0834 (27) Å, b = 14.2224 (16) Å, c = 14.1649 (24) Å, β = 95.871 (15)°, V = 2621.9 (8) Å3, and Z = 4; treatment of all 3434 unique data led to final values of RF = 3.7% and RwF = 3.3%. (RF = 2.5% and RwF = 3.0% for those 2781 data with |F0| > 6σ(|F0|).) The chloronaphthyl cluster of Co3(CO)9 μ3-CCH(C10H6Cl)2] (6) crystallizes in the triclinic space group PI with α = 8.839 (3) Å, b = 12.156 (4) Å, c = 16.513 (5) Å, α = 105.974 (25)°, β = 92.280 (25)°, γ = 115.512 (22)°, V = 1513.57 (84) Å3, and Z = 2; treatment of the 3620 unique data led to final values of RF = 4.8% and RWF = 5.3%. At -120 °C, the cobalt carbonyl ligands of the phenyl clusters 3 and 4 exhibit a 6:3 splitting in their13C NMR spectra; however, the naphthyl cluster 6 does not show this effect. These data are discussed in terms of the ability of the aryl groups to obstruct the fluxionality of the cobalt carbonyl ligands. © 1990, American Chemical Society. All rights reserved.