Abstract: By using the topological index Z and Z-counting polynomial proposed by the present author isospectral (IS) pairs of acyclic conjugated polyenes (C2nH2n+2) were studied. Besides the hitherto known smallest pair of n = 6, four and twenty seven pairs of n = 7 and 8, respectively, were first reported. Inspection of these results revealed several new features of IS tree graphs, i.e., appea...

We apply the valence shell model OM2 [W. Weber and W. Thiel, Theor. Chem. Acc. 103, 495, (2000)] combined with multireference configuration interaction (MRCI) to compute the vertical excitation energies and transition dipole moments of the low-energy singlet excitations in the polyenes with 4 ≤ N ≤ 22π-electrons. We find that the OM2/MRCI descriptions closely resemble those of Pariser-Parr-Popl...

The structure of the title compound, 1,3-diphenyl-2-benzofuran, C(20)H(14)O, exhibits a distinct alternation of short [mean 1.361 (3) Å] and long [mean 1.431 (3) Å] C-C bonds around the benzofuran ring system, indicating a predominantly polyene character. Over 60 Diels-Alder adducts of this commercially available furan have been structurally characterized, but this is the first report of the st...

Progress in our understanding of ultrafast light-induced processes in molecules is best achieved through a close combination of experimental and theoretical approaches. Direct comparison is obtained if theory is able to directly reproduce experimental observables. Here, we present a joint approach comparing time-resolved photoelectron spectroscopy (TRPES) with ab initio multiple spawning (AIMS)...

The alterations in the absorption and fluorescence spectra observed for the polyene antibiotics filipin and nystatin in the presence of cholesterol are due to an exciton interaction (polyene aggregates) and cannot be attributed to a specific sterol-antibiotic complex. Filipin and nystatin molecules partition into the sterol aggregates, these structures being very efficient to induce exciton int...

Singlet exciton fission allows the fast and efficient generation of two spin triplet states from one photoexcited singlet. It has the potential to improve organic photovoltaics, enabling efficient coupling to the blue to ultraviolet region of the solar spectrum to capture the energy generally lost as waste heat. However, many questions remain about the underlying fission mechanism. The relation...