Donor-acceptor complexes incorporating ferrocenes: Spectroelectrochemical characterisation, quadratic hyperpolarisabilities and the effects of oxidising and reducing agents

Publication Type:
Journal Article
Journal of the Chemical Society, Dalton Transactions, 2001, (20), pp. 3025 - 3038
Issue Date:
Filename Description Size
Thumbnail2006006466OK.pdf285.54 kB
Adobe PDF
Full metadata record
The donor-acceptor complexes [Fe(C5H5){C5H4QNHM(NO)(Tp Me,Me)X}] {TpMe,Me = tris(3,5-dimethylpyrazolyl)borate; Q = nothing, M = Mo, X = Cl, Br, I; M = W, X = Cl; Q = C6H4, M = Mo, X = Cl, Br, I; M = W, X = Cl; Q = CH=CHC6H4 or N=NC6H4, M = Mo, X = Cl), which contain 16-valence electron metal nitrosyl centres, [Fe(C5H5){C5H4QpyMo(NO)(Tp Me,Me)Cl}] (py = 4-pyridyl; Q = CH=CH, CH=CHCO, N=CH and C6H4CH=CH), [Fe(C5Me4H){C5H4CH=CHpyMo(NO) (TpMe,Me)Cl}] and [Fe(C5Me4H)(C5Me4QpyZ)] {Q = CH=CH or CH=N, Z = Mo(NO)(TpMe,Me)Cl or W(CO)5; Q=2,4-CH=CH(C4H2S)CH=CH, Z = W(CO)5 or Me+I-}, some of which contain 17-valence electron molybdenum nitrosyl centres, and [Fe(C5Me4H){C5Me4CH=CH(C 4H2S)CH=CHpy}], have been characterised electrochemically, by their electronic spectra, and spectroelectrochemically. Hyper-Rayleigh scattering was used to determine the first hyperpolarisability, β, the data showing that (a) β is dependent on the metal in the acceptor fragment, (b) β increased when Cl or Br was replaced by I and (c) β increased when the number of methyl groups on the cyclopentadienyl rings increased. The β-values for comparable complexes containing {Mo(NO)(TpMe,Me)Cl} and {W(CO)5} moieties were similar. Chemical oxidation of the ferrocenyl or chemical reduction of the molybdenum nitrosyl acceptor fragments in selected complexes caused a reduction of between 25% and 100% in the NLO response. X-Ray structural studies of [Fe(C5H5){C5H4NHMo(NO)(Tp Me,Me)Cl}] (P1̄) and [Fe(C5Me4H){C5Me4CH=CHpyMo(NO) (TpMe,Me)Cl}] (P1̄) are reported.
Please use this identifier to cite or link to this item: