138128-54-8Relevant articles and documents
π-Arene complexes. 7. Heterobimetallic complexes of chromium and manganese with bridging σ,π-benzene and -benzoyl ligands
Lotz, Simon,Schindehutte, Minet,Van Rooyen, Petrus H.
, p. 629 - 639 (2008/10/08)
The complexes [Cr{η6-C6H4XLi}(CO)3] (X = H (a), F (b)) react with [Mn(CO)5Br] to produce novel heterobimetallic compounds with bridging σ,π-benzoyl ligands, (η6-{(CO)5Mn}C(P)C6H 4X)Cr(CO)3 (1). When the reaction was executed in the presence of P(OMe)3, complexes with a bridging benzoyl, (η6-{(CO)4(P-(OMe)3)Mn}C(O)C 6H5)Cr(CO)3 (1c (higher yield)), as well as a bridging phenyl ligand, (η6-{(CO)4(P-(OMe)3)Mn}C6H 5)Cr(CO)3 (3c), were obtained. By the refluxing of 1c in hexane, it was converted quantitatively into 3c. Using PPh3 instead, the only product from the reaction was the unique complex (η6-{(CO)4(PPh3)Mn}C6H 4X)Cr(CO)3 (3a,b). Bridging benzoyl complexes (η6-{(CO)3(L L)Mn}C-(O)C6H5}Cr(CO)3 were obtained with L L = dppe (Ph2PCH2CH2PPh2) (4a) or L L = tmeda (Me2NCH2CH2NMe2) (4b). The formation of [(η6:η6-XC6H4C(O)C 6H4X){Cr(CO)3}2] (2) as a minor byproduct from the reactions which generated benzoyl dimers represents an interesting carbonyl-transfer reaction. Upon isolation of 1a from a dichloromethane-hexane solution, the complex crystallizes in the orthorhombic space group Pna21, with a = 13.084 (2) A?, b = 6.089 (2) A?, c = 40.036 (5) A?, and Z = 8 with two molecules in the asymmetric unit. The structure of 1a was determined from 5306 unique data (0 ≤ h ≤ 18, 0 ≤ k ≤ 8, 0 ≤ l ≤ 56), and refinement of 469 variables against 3521 observed (>σ(I)) data yielded Rw = 0.059. Recrystallization of the manganese-phosphorous complex 3a from a dichloromethane-hexane solution yielded crystals that were orthorhombic, Pbca, with a = 17.217 (2) A?, b = 16.407 (5) A?, c = 20.530 (10) A?, and Z = 8. The structure of 3a was determined from 8996 unique data (0 ≤ h ≤ 24, 0 ≤ k ≤ 22, 0 ≤ l ≤ 28), and refinement of 371 variables against 3465 observed (>3σ(I)) data yielded Rw = 0.035.
