Search

Reactions of ferrocenoylsilanes 1 with lithium aluminium hydride and organometallic reagents show unusual behaviour in that the ferrocenyl aldehydes 4 and ketones 5−9 are obtained instead of the expected secondary and tertiary silylated alcohols. This paper also reports on the synthesis and reactivity of the first planar chiral enantiomerically pure ferrocenoylsilane 1d that offers the possibility of synthesizing planar chiral enantiomerically pure 1,2-disubstituted aldehyde 4b and ketones 5b, 6b, 7b, 8 and 9. A mechanistic hypothesis is proposed for explaining the obtained results.

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.

Carbon nanostructures, or nanocarbons (CNSs), i.e. the low-dimensional nanomaterials that comprise 0D fullerenes, 1D nanotubes and 2D graphene, have emerged over the last two decades in the field of new molecular materials for their unique structural and electronic properties, prompting a huge interest worldwide both from the viewpoint of fundamental research and for their application in molecular electronics, materials science, energy storage and conversion, biomedicine, sensing and biosensing. Because of the several and diverse technological applications so far proposed, and of the many more expected in the near future, the present volume is addressed to researchers from several different areas: chemistry and materials chemistry, nanotech- nology, medicine and industrial research.

A metal organic framework (MOF) based on the [Cu(4)I(4)DABCO(2)] cluster (DABCO = 1,4-diazabicyclo[2.2.2]octane), MOF 1, shows bright emission with a maximum at 556 nm and an emission quantum yield of 0.53 in the solid state. When the large cavities of the MOF are loaded during the synthesis with different amounts of ferrocene {FeCp2, [((5)-C5H5)(2)Fe-II]}, the luminescence of MOF 1 decreases with the increase in the ferrocene content, reaching an almost complete quenching for 3.5 wt.-% of cage loading, corresponding to the complete filling of the MOF cavities. When an electric potential is applied to the FeCp2@MOF 1 deposited onto an ITO glass, the (FeCp2)-Cp-II is oxidised to (FeCp2+)-Cp-III, and the MOF 1 emission is partially switched on again, indicating that a photoinduced electron-transfer reaction is contributing to the quenching process.