Diboron- and Diaza-Doped Anthracenes and Phenanthrenes: Their Electronic Structures for Being Singlet Fission Chromophores

<p>We used quantum chemistry methods at the levels of mixed-reference spin-flipping time-dependent density functional theory and multireference perturbation theory to study diboron- and diaza-doped anthracenes and phenanthrenes. This class of structures recently surged as potential singlet fission chromophores. We studied electronic structures of their excited states and clarify the reasons why they satisfy or fail to satisfy the energy criteria for singlet fission chromophores. Many studied structures have their S₁ states not dominated by HOMO->LUMO excitation, so that they cannot be described using the conventional two sites model. This is attributed to frontier orbital energy shifts induced by the doping and different charge transfer energies in different one-electron singlet excitations, or in other words different polarizations of hole and/or particle orbitals in their S₁ and T₁ states. There is a mirror relation between the orbital energy shifts induced by diboron- and diaza-dopings, which, together with alternant hydrocarbon pairings of occupied and unoccupied orbitals, leads to more mirror relations between the excited states' electronic structures of the two types of doped structures. </p>

Diboron- and Diaza-Doped Anthracenes and Phenanthrenes: Their Electronic Structures for Being Singlet Fission Chromophores

<p>We used quantum chemistry methods at the levels of mixed-reference spin-flipping time-dependent density functional theory and multireference perturbation theory to study diboron- and diaza-doped anthracenes and phenanthrenes. This class of structures recently surged as potential singlet fission chromophores. We studied electronic structures of their excited states and clarify the reasons why they satisfy or fail to satisfy the energy criteria for singlet fission chromophores. Many studied structures have their S₁ states not dominated by HOMO->LUMO excitation, so that they cannot be described using the conventional two sites model. This is attributed to frontier orbital energy shifts induced by the doping and different charge transfer energies in different one-electron singlet excitations, or in other words different polarizations of hole and/or particle orbitals in their S₁ and T₁ states. There is a mirror relation between the orbital energy shifts induced by diboron- and diaza-dopings, which, together with alternant hydrocarbon pairings of occupied and unoccupied orbitals, leads to more mirror relations between the excited states' electronic structures of the two types of doped structures. </p>

Un « rapp ort de miroir ». Relation amoureuse et réflexion politique chez Merleau-Ponty

This article studies a link between perception and politics by seeking, in Merleau-Ponty’s work, something like a “mirror relation” in the domains of encounters of love and politics. While in Phenomenology of Perception the analysis of sexuality seemingly renders love impossible, in the courses on Institution, Merleau-Ponty affirms the possibility of love by characterizing it as an institution, a sensible idea, a “mirror relation”. When the lover demands signs of love from the loved one, he demands to see in the eyes, the voice, and the experience of the other his own reflection, the reflection of his experience, his words, his gestures, and the demand of love that he is formulating. The promise of love is thus an institution of sense which sheds a new light on all actions past and future, it is a way of overcoming contingency. Conceiving of politics as a “mirror relation” thus means adopting a careful philosophy that observes the event like a mirror and gives place to sensible ideas, at the intersection of gazes understood as a “type of reflection”.