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Alessandro Troisi

Publications and source records attributed to Alessandro Troisi.

2 recordsLinked to original sources
PubMed2002

Molecular rectification through electric field induced conformational changes.

A new approach for the design of a molecular rectifier is proposed. Using a simple model, we have shown that conformational changes induced by the electric field may lead to a rectifying junction. The simplest possible rectifier of this kind presents two almost isoenergetic conformations, with different conductances and dipole moments. A simple equation allows for the estimation of the range of molecular parameters and temperatures that lead to an effective rectification. Examples show that rectification based on this mechanism is also possible at room temperature.

Journal Article↗
PubMed2002

Structure and photophysics of an old, new molecule: 1,3,6,8-tetraazatricyclo[4.4.1.1(3,8)]dodecane.

More than a century after its initial synthesis, the static and dynamic geometry of 1,3,6,8-tetraazatricyclo [4.4.1.1(3,8)]dodecane (TTD), a fully saturated cage-like molecule, is finally established. Detection and modeling of the supersonic jet fluorescence excitation and emission spectra show that the molecule undergoes interconversion between two S(4) symmetry minima. The barrier at the D(2d) symmetric conformation is only 105 cm(-1), i.e., approximately 0.3 kcal mol(-1), and is overcome along a carbon-carbon torsional mode of a(2) symmetry. The presence of an S(4) conformation is corroborated by a Raman investigation. When excited to the first excited singlet state, the 3s Rydberg state, the molecule adopts a geometry with D(2d) symmetry. The satisfactory description of the spectroscopy of TTD obtained by a combination of quantum chemical and quantum mechanical models is discussed, and the apparent conflict between the present results and nuclear magnetic resonance and X-ray diffraction experiments is solved. Because of the close analogy between a Rydberg state and the ground state of the radical cation regarding geometry and spectroscopic properties, it is concluded that the radical cation is also of D(2d) symmetry.

Journal Article↗