The longest wave absorption band of the tetramethylthiotetrathiafulvalene cation radical, which is usually interpreted as a p-dimer band, is shown to be the intrinsic cation radical absorption, all studied cation radicals in solution at room temperature exist as paramagnetic monomers and only tetrathiafulvelene and tetramethyltetrathiafulvalene cation radicals undergo p-dimerization at low temperatures.

The physico‐chemical relationship between living and non‐living systems remains a question of intense debate. This paper introduces the concept of dynamic kinetic stability as a means of incorporating living systems within a conventional physico‐chemical framework. Its essence, all replicating systems, both animate and inanimate, represent elements of a replicator space. In contrast to the world of non‐replicating systems (all inanimate), where selection is fundamentally thermodynamic, selection within replicator space is effectively kinetic. Driven by mutagenic autocatalysis selection in replicator space leads from kinetically less stable systems to kinetically more stable systems. Our kinetic approach suggests that all living systems may be thought of as manifesting a kinetic state of matter (as opposed to the traditional thermodynamic states), and allows the translation of key Darwinian concepts, such as fitness and natural selection, into traditional physico‐chemical terms that are applicable at the molecular level. Copyright © 2004 John Wiley & Sons, Ltd.

This result is consistent with the cyclic structure 2 and inconsistent with a cyclic dimer, in which two stilbene units would be aligned in the base-stacked conformation and therefore exhibit excirner fluorescence.

No abstract

No abstract