Organometallic complexes with metal-metal bonds. 18. Syntheses of tetrametallic planar, triangulated mixed-metal palladium clusters. X-ray crystal structures of Pd2M2(.eta.5-C5H5)2(.mu.3-CO)2(.mu.2-CO)4(PEt3)2 with M = Cr, Mo, and W

Regiospecific Reaction between Dimetallic Phosphido-Bridged W−W Complexes and Phosphane Imide − Electrophilic Site Switching by Metal−Metal Bond Formation

“…The isocyanide ligand is coordinated to W(1) and is cis to the phosphido bridge ligand. The WϪW distance of 4.4548(7) Å and the W(1)ϪPϪW(2) angle of 116.71(9)°in 5 are similar to the WϪW distance of 4.5096 (11) Å and the WϪPϪW angle of 118.38(13)°in 1. [2d] This indicates that the steric hindrance of the isocyanide ligand at the cis position in 5 is only slightly greater than the steric hindrance of the corresponding CO ligand in 1.…”

“…A yellow solution of Na[CpW(CO) 3 ]·2DME [11] (0.350 g, 0.65 mmol) in THF (100 mL) was cooled to 0°C. A solution of PPh 2 Cl (0.132 mL, 0.71 mmol) in THF (50 mL) was then slowly added to the above solution.…”

2-η3-Allyl-1,1,1-tricarbonyl-μ-(η1:η6-diphenylmethyl)chromiumpalladium(Pd–Cr) at 130 K

“…Both molecules of (II) have very similar geometric parameters which are quite close to those found for (I). The Pd--Cr distances in (II) [2.766(1) and 2.770(1) A] correspond to direct metal-metal bonds and are nearly the same length as in (I) (2.764 A) and in Pd2Cr2(r/5-CsHs)2(#3 -CO)2(#-CO)4(PEt3)2 (2.741 and 2.777 A), the only other structurally characterized complex with Pd--Cr bonds (Bender, Braunstein, Jud & Dusausoy, 1983).…”

Chemistry of vinylidene complexes. XVI. Crystal and molecular structure of the novel tetranuclear μ2-μ3-bis-vinylidene complex (η2-dppe)PdMn(μ3-CCHPh)PdMn(μ-CCHPh)(CO)4Cp2

“…Only one of four carbonyl groups, namely C (3)O (3), is terminal (the bond lengths are C(3)-O (3) 1.166 (4) and Mn (1) [16].…”