Crystal and molecular structure of .mu.-(.eta.5:.eta.1-cyclopentadienyl)-[(.eta.5-cyclopentadienyl)carbonylmolybdenum][tetracarbonylmanganese]

Abstract

The structure of the title compound, ( 5-05 5)(00) (µ-( ;5: 1-5 4)) (00)4, has been determined by a three-dimensional X-ray diffraction study. The compound crystallizes in the triclinic space group Pi with a = 8.056 (1) Á, b = 9.322 (3) A, c = 11.927 (2) Á, a = 98.44 (3)°, ß = 82.97 (3)°, and y = 123.39 (2)°. The density of 1.89 g cm'3 calculated on the basis of two molecules in the unit cell agrees with the measured density of 1.88 g cm"3. Diffraction data to 29max = 65°( Mo Ka radiation) were collected on a Picker four-circle automated diffractometer. The structure was solved by the heavy-atom method and refined by full-matrix least-squares procedures to a conventional discrepancy index R = 0.045 on the basis of 4900 unique reflections. The C5H4 ring has C-C bond distances of average value 1.424 Á and appears to be a cyclopentadienyl ring rather than a dienecarbenoid ring. One carbon atom in the C5H4 ring is rather close to the Mn atom, Mn-C = 2.005 (4) Á and Mo-Mn = 2.9605 (8) Á. The angle Mo-Mn-C involving these three atoms is 49°. Apart from this cis compression, the disposition of the four CO groups around Mn is approximately octahedral; i.e., angles involving CCo and Mn are approximately 90°. The configuration around Mo is very similar to that in ( 75-5 5)2 2.

Hexacarbonyl-1κ4C,2κ2C-[μ-1κC6:2(η5)-6-methylfulvene]diruthenium(Ru—Ru), [Ru2(C5H4CHCH3)(CO)6]

“…Although in the present study this shortening is not significant, it probably corresponds to a structural feature of the ring, since in (111), (IV) and binuclear complexes with a #-r/l:r/5-C5H4 unit (Hoxmeier, Knobler & Kaesz, 1979, and references therein; Herrmann, Kriechbaum, Bauer, Guggolz & Ziegler, 1981) it was also observed that the C----C bond opposite to the a-bonded C atom was the shortest of the ring. The C(1)---C(6) distance is consistent with partial double-bond character, when compared with the value …”

Synthesis and reactivity of dimetallacyclopentenone complexes [Ru2(CO)(μ-CO){μ-C(O)CR1CR2}(η-C5H5)2] (R1 = Me or Ph; R2 = CO2Me)

“…This pattern is consistent with that seen for µ-C 5 H 4 groups in several other complexes. 11 The asymmetric nature of the alkyne unit in complex 7 gives rise to the possibility of isomers in which the phenyl and carboxylate substituents have effectively swapped places. However, only the isomer shown in Fig.…”

Novel Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Polymetal Carbonyl Anions. An Approach to Trimetal Bridging Carbyne Complexes

“…The structure of complex 16 (Figure ) was established by single-crystal X-ray diffraction. The Mo−Mn distance of 2.786(3) Å is somewhat longer than that found in the analogous compound [MoMn(CO)(η-C 5 H 5 ){μ-(η 5 :η 1 -C 5 H 4 )}] (2.7605(8) Å) . The Mo−μ-S(1) and Mo−μ-S(2) bond lengths are 2.491(4) and 2.507(5) Å, respectively, which are nearly the same as those in the thiolato-bridged molybdenum compound [Et 3 NH] 2 [Mo 2 (NNHPh)(NNPh)(SCH 2 CH 2 S) 3 (SCH 2 CH 2 SH)] ( average Mo−μ-S = 2.501(6) Å), while the distances of Mn−μ-S(1) and Mn−μ-S(2), 2.349(5) and 2.344(5) Å, respectively, are significantly longer than the corresponding bonds in the analogous thiolato-bridged manganese carbonyl complex [MnCr 2 (μ-SCMe 3 )(μ 3 -S) 2 (CO) 3 ] (Mn−S(1) = 2.272(2) Å, Mn−S(2) = 2.297(2) Å) …”