95406-94-3Relevant academic research and scientific papers
Mixed-metal dimers. 3. Substitution reactions of [(η5-C5H5)Fe(CO)2M(CO) 5] (M = Mn, Re) and the x-ray crystal structure determination of [(η5-C5H5)Fe(CO)2M(CO) 4(CNBu-t)] (M = Mn, Re)
Johnston, Peter,Hutchings, Graham J.,Denner, Louis,Boeyens, Jan C. A.,Coville, Neil J.
, p. 1292 - 1300 (2008/10/08)
The reaction between [(η5-C5H5)Fe(CO)2M(CO) 5] (M = Mn, 1; M = Re, 2) and L (L = t-BuNC, 2,6-Me2C6H3NC, PMePh2, P(OMe)3) under a variety of conditions is reported. Reaction between 2 and L (either thermally at 90°C, or in the presence of PdO as catalyst, or Me3NO) gives only the Re-substituted product [(η5-C5H5)Fe(CO)2Re(CO) 4L]. All attempts to synthesize the Fe-substituted complex, e.g., via the reaction between [(η5-C5H5)Fe(CO)(CNR)]+ and [Re(CO)5]-, failed. The thermal reaction between 1 and L yielded the Fe-substituted salts [(η5-C5H5)Fe(CO)L2]+ or [(η5-C5H5)FeL3]+. However, reaction of 1 with Me3NO followed by addition of L yielded either [(η5-C5H5)Fe(CO)2Mn(CO) 4(CNR)] (R = t-Bu 2,6-Me2C6H3NC) or [(η5-C5H5)Fe(CO)2]2 and [Mn2(CO)8L2] (L = P(OMe)3, PMePh2). Attempts to synthesize the Fe-substituted mixed-metal dimers failed. The new substituted mixed-metal dimers were completely characterized by IR NMR, and mass spectrometry as well as thermal and photochemical decomposition studies. The crystal and molecular structures of [(η5-C5H5)Fe(CO)2M(CO) 4(CNBu-t)] (M = Mn, 3; M = Re, 4) were determined. 3: space group P21/c, Z = 4, a = 8.715 (2) ?, b = 13.884 (2) ?, c = 15.579 (3) ?, β = 96.95 (2)°. 4: space group P21/n, a = 11.313 (2) ?, b = 11.055 (4) ?, c = 15.732 (3) ?, β = 107.03 (1)°. The structures were refined to R values of 0.050 and 0.037, respectively. In both structures the t-BuNC was attached to the non-Fe atom and in an equatorial site.
The PdO-catalyzed reaction between [Re2(CO)10] and isocyanides
Harris, Gillian W.,Coville, Neil J.
, p. 908 - 914 (2008/10/08)
The reaction between [Re2(CO)10] and RNC (R = Me, t-Bu, C6H5CH2, C6H11, 2,6-Me2C6H3) is catalyzed by PdO to yield the products [Re2(CO)10-n(CNR)n] (n = 1-3, R = t-Bu, C6H5CH2, C6H11; n = 1-4, R = Me, 2,6-Me2C6H3) rapidly and in moderate to excellent yields. The reaction occurs via stepwise replacement of CO groups and mixed-isocyanide derivatives can thus be synthesized, e.g., [Re2(CO)8(CNBu-t)-(CNC6H3Me 2-2,6)]. The products have been completely characterized by IR and NMR spectroscopy and for certain derivatives by mass spectrometry. A correlation between the above spectroscopic parameters and the product geometry, after crystallographic determination of the structures of pertinent substituted derivatives, has been made. In all products the isocyanide ligands occupy cis equatorial positions on either the same or different Re atoms, indicating the dominance of electronic rather than steric factors in the control of the final product geometry. Labeling studies using [Re(13CO)12] indicate that the PdO-catalyzed reaction to yield [Re2(CO)9(CNBu-t)] occurs via a CO dissociative mechanism rather than a process involving metal-metal bond cleavage.
