[(η⁵‐Cp*)AlFe(CO)₄] – Synthese, Struktur, Bindungsverhältnisse

Abstract

Die Bindungsverhältnisse im präzedenzlosen Komplex [Cp*AlFe(CO)4] wurden anhand des Modells [CpAlFe(CO)4] quantentheoretisch untersucht. Für diesen Komplex ist die Donor‐Acceptor‐Bindung Al → Fe charakteristisch (rechts), deren Stärke etwa 50 kcal mol−1 beträgt.

Synthesis and Electronic Structure of a Ferroborirene

“…This situation is typical for a closed-shell donor-acceptor bond, which was previously found for transition-metal complexes with Group 13 diyl ligands ER (E = B-Tl). [24] Compound 2 M is clearly characterized by the AIM method as a three-membered cyclic species possessing two BÀC and one CÀC bond path and one BC 2 ring critical point.…”

Methylgallium as a Terminal Ligand in [(Cp*Ga)4Rh(GaCH3)]+

“…A similar discussion has taken place on the complexes [M(CO) n (ECp*)] (M = Fe, Cr; E = Al, Ga; n = 4, 5), for which the Group 13 center has been considered as E III rather than E I based on the electronegativity of the {M(CO) n } fragment. [14,15] Nevertheless, taking into account complexes such as [M(CO) 3 (GaCp*) 3 ] [16] (M = Mo, W), the whole series of compounds may be better described as E I complexes.…”

GaI as Ligand in Transition‐Metal Complexes—An Alternative to CO or N2?

“…The question about whether Group 13-17 diatomics (referred to here as EX) such as BF can likewise function as ligands has intrigued researchers for a long time. ECp* can occur as a terminal or bridging ligand, as exemplified in the compounds [Cp*E À Fe(CO) 4 ] (E = B, [8] Al, [9] Ga [10] ), [Cp*ECr(CO) 5 ] (E = Al, [11] Ga, [12] In, [13] ), and [(CO) 3 Co(m 2 -ECp*) 2 Co(CO) 3 ] (E = Al, [13] Ga [10] ). [1] However, only a few reports on reactions with BF (e.g.…”

“…ECp* can occur as a terminal or bridging ligand, as exemplified in the compounds [Cp*E À Fe(CO) 4 ] (E = B, [8] Al, [9] Ga [10] ), [Cp*ECr(CO) 5 ] (E = Al, [11] Ga, [12] In, [13] ), and [(CO) 3 Co(m 2 -ECp*) 2 Co(CO) 3 ] (E = Al, [13] Ga [10] ). Two general synthetic routes to ER transition-metal complexes were established: [7] the substitution of weakly bound ligands by compounds with monovalent aluminum, gallium, and indium, as well as the salt elimination between carbonyl metalates and halogen derivatives of Group 13 elements.…”

“…[1] To date no transition-metal complex with a BF ligand has been described, although, according to quantum-chemical calculations a metal-BF bond should generally be stronger than the corresponding metal-CO bond. ECp* can occur as a terminal or bridging ligand, as exemplified in the compounds [Cp*E À Fe(CO) 4 ] (E = B, [8] Al, [9] Ga [10] ), [Cp*ECr(CO) 5 ] (E = Al, [11] Ga, [12] In, [13] ), and [(CO) 3 Co(m 2 -ECp*) 2 Co(CO) 3 ] (E = Al, [13] Ga [10] ). This, together with the low energy LUMO, is one of the reasons for the high reactivity towards nucleophilic attack at the positively polarized Group 13 element, which reduces the stability of the complex.…”