[(Cp^**CoH)₂‐μ‐{η²:η²‐cis‐μ‐[(C₂H₅)₂Al–CH = CH–Al(C₂H₅)₂]}] and [{Cp^*(η²‐C₂H₄)CoAl(C₂H₅)}₂]: Synthesis and Structure of Unusual Co–Al Cluster Compounds

Abstract

COMMUNICATIONS [ (Cp"*CoH)2-/t-{q2 :q2-&-/t-[ (CZH5)2Al-CH = CH -Al(C2H5),]}] and [{Cp*(q2-C2H,)CoAl(C zH,J] 2 ] :

Adduct Formation and Single and Double Deprotonation of Cp*(PMe3)Ir(H)2 with Main Group Metal Alkyls and Aryls: Synthesis and Structure of Three Novel Ir−Al and Ir−Mg Heterobimetallics

“…The ORTEP diagram in Figure shows that this complex contains two Cp*IrPMe 3 fragments bridged by two EtAl units. The structure is similar to that found in (Cp*Co(C 2 H 4 )AlEt) 2 …”

“…The geometry of both (Cp*(PMe 3 )Ir(MgPh)(H)) 2 and Cp*(PMe 3 )Ir(H) 2 AlPh 3 indicate that the Ir center in Cp*(PMe 3 )Ir is Lewis basic. Very few three-coordinate aluminum-transition metal organometallic complexes have been prepared and structurally characterized; (Cp*(C 2 H 4 )CoAlEt) 2 , mentioned above, and (CpNiAlCp*) 2 are 3d transition metal examples.…”

Synthesis, Structure, and Bonding of a Polyhedral Al2Co2 Cluster

“…The Co−Co bond (2.772(2) Å) is significantly longer than in Co 2 (CO) 8 ( 2 ) (2.5290(8) Å), and the Al−Al distance (3.121(3) Å) is longer than that of a typical Al−Al bond (2.660(1) Å), as well as those in 1 (2.769 Å (2.773(4)−2.767(5) Å)),1a by about 13%. On the other hand, the Al−Co interactions (2.377 Å) are of strength similar to that in the only other known example containing an Al−Co bond, {Cp*(η 2 -C 2 H 4 )Co−AlEt} 2 ( 4 ), possessing a central planar Al 2 Co 2 ring with a Al−Co bond length of 2.333(1) Å. The Co−C bonds in 3 (1.76 Å) are shorter than those in Co 2 (CO) 8 by about 0.07 Å.…”

“…Its structure and bonding, especially with respect to three-center bonding (Al−Co−Al in addition to a Co−Al−Co contribution) and to direct Al−Co bonds, are discussed. The former situation is unique; the latter have been observed only once before …”

Syntheses and Structures of Terminal Arylalumylene Complexes

“…[1] The chemistry of borylene complexes has been extensively developed, [2] whereas the examples of the heavier group 13 metallylene complexes, having the formula of [M(ER) m L n ] (R: anionic monodentate ligands), have been limited for the gallium and indium homologues, and have yet to be reported for aluminum. [3] Although Lewis-base-coordinated terminal alumylene complexes (e.g., A, B, and C; Figure 1) have been synthesized as stable compounds, [4][5][6][7] there have been no alumylene complexes featuring two-coordinate subvalent aluminum moieties (i.e., D). Because the coordination of Lewis bases may mask the intrinsic nature of the alumylene ligands, the development of Lewis base-free alumylene complexes is desirable so as to elucidate the bonding situation between the alumylene and transition-metal moieties.…”