The first structurally characterized coordination compound containing direct Al–Cr bonding: Cp*Al–Cr(CO)5

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.…”

Coordination Chemistry of Aluminum, Gallium, and Indium at Transition Metals

“…Interesting results can be expected from this promising new field. [172,173] Scheme 6. Synthesis of M ± In complexes and clusters of the types D, E, and F by ligand substitution.…”

“…[140] In the light of a fast developing chemistry of lowcoordinate centers E, some remarks on the MÀE bonding conditions and the substituent effects seem to be warranted. Quantum chemical DFT calculations have meanwhile been carried out by several groups on the model complexes [(CO) 4 FeÀAlCp], [79,83] [(CO) 5 CrAlCp], [172] [(CO) 4 FeÀGa(h 1 -C 6 H 5 )], [136,140] [(CO) 5 MÀEX], [(CO) 5 MÀEXL 2 ] (E B, Al, Ga, In, Tl; X H, Cl; L NH 3 ) [80] and [L'(CO) 3 Co-GaX 2 L] (X H, Cl; L' PH 3 ). [141] All model complexes were compared to closely related examples, the molecular structures of which were known.…”

“…Being a soft donor, the Cp* ligand is rather flexible and the distance EÀCp* is a sensitive measure of the positive polarization of the centre E in the M À E complexes. [83,84,172] Already the very different electronegativities of the metal atoms M and E suggest strong polar MÀE bonds, and the more so if the group electronegativity of the carbonyl metal fragments, which are similar to O and F atoms, is taken into account. [146] Thus the description of the fragments Cp*E in the carbonyl metal complexes in the sense of a formally lower oxidation state of i for E has also been criticized.…”

“…For [(CO) 5 CrÀECp*] the ion [CrECp*] is found as base peak (E Al, Ga). [84,172] The fragmentation behavior of a potential MOCVD precursor under the conditions prevailing in a mass spectrometer cannot automatically be compared to the conditions of a thermal MOCVD experiment. In the cases we examined, however, a correlation was observed.…”