78357-01-4Relevant academic research and scientific papers
DOUBLY LINKED DINUCLEAR TRANSITION METAL COMPLEXES. SYNTHESIS OF Me3Si2L (L = dppe, dppm)
Nelson, Gregory O.,Wright, Michael E.
, p. C21 - C23 (1981)
Photolysis of Me2Si2 in the presence of bis-phosphine ligands (dppe and dppm) gives good yields of doubly linked diiron complexes.In the reaction with dppe, a mechanically linked tetranuclear species can also be isolated.
Synthesis, characterization, and electrochemistry of the bis-bridged complexes Me2Si[η5-C5H4Fe(CO)] 2[Ph2P(CH2)n PPh2] (n = 1-3) and [Me2Si[(η5-C5H4) 2Fe2(CO)3]]2[Ph ...
Wright, Michael E.,Mezza, Thomas M.,Nelson, Gregory O.,Armstrong, Neal R.,Day, Victor W.,Thompson, Michael R.
, p. 1711 - 1718 (2008/10/08)
Full title: Synthesis, characterization, and electrochemistry of the bis-bridged complexes Me2Si[η5-C5H4Fe(CO)] 2[Ph2P(CH2)n PPh2] (n = 1-3) and [Me2Si[(η5-C5H4) 2Fe2(CO)3]]2[Ph2P(CH 2)nPPh2] (n = 2, 3). Molecular structures of Me2Si[η5-C5H4Fe(CO)] 2[Ph2P(CH2)nPPh2] where n = 1 and 3. Photolysis of Me2Si[η5-C5H4Fe(CO) 2]2 (1) with a series of bis(phosphines) (L = Ph2P(CH2)nPPh2, where n = 1, 2, and 3) leads to the formation of substituted dinuclear and tetranuclear compounds of the form Me2Si[η5-C5H4Fe(CO)] 2[L] and [Me2Si[(η5-C5H4) 2Fe2(CO)3]]2[L], respectively. The ratio of these two types of compounds is dependent upon the ligand size (number of methylene units), stoichiometry, and the overall concentration employed. With the small ligands and dilute conditions, formation of the dinuclear product is favored. Under more concentrated reaction conditions and when an excess of 1 is used, the tetranuclear type of product becomes dominant. The electrochemistry of the dinuclear compounds indicate that both the silyl and the bis(phosphine) bridges are capable of stabilizing a two-electron oxidation product. This is demonstrated in the case of L = dppm where we observe, by fast-scan cyclic voltammetry, two, one-electron reversible oxidation steps. The structure of Me2Si[η5-C5H4Fe(CO)] 2[dppm] (3a) is determined by X-ray diffraction. It crystallizes in the space group Pnma (No. 62) with a = 13.754 (4) A?, b = 17.707 (4) A?, c = 13.771 (3) A? and α, β, and γ = 90.00° with Z = 4. The structure was refined to R1 = 0.041 and R2 = 0.045 for 2226 independent reflections having I > 3σ(I). The structure of Me2Si[η5-C5H4Fe(CO)] 2[dppp] (3c) is also determined by X-ray diffraction. It crystallizes in the space group P1 (No. 2) with a = 11.638 (11) A?, b = 11.833 (11) A?, c = 16.289 (14) A?, α = 111.22 (6)°, β = 72.67 (7)°, and γ = 107.02 (7)° with Z = 2. The structure is refined to R1 = 0.067 and R2 = 0.076 for 4115 independent reflections having I > 3σ(I). The overall geometry of 3a compared to 3c implies that some distortion occurs from the steric requirements of the larger dppp ligand. This includes a significant lengthening of the Fe-Fe bond in complex 3c by 0.024 (3) A? relative to 3a.
