J. M. Leclercq

TL;DR: In this paper, it is suggested that the low excitation energy of rhodopsin can be obtained without actual protonation of the Schiff-base prior to photon absorption.

TL;DR: In this paper, it was shown on the basis of quantum chemical and spectroscopic arguments that through a consideration of the hydrogen bond and other intermolecular associations affecting the Schiff-base of retinal in the ground and excited states, a new assessment can be made of the conditions related to the photochemical primary step of vision.

TL;DR: The causes of the instability of bathorhodopsin are discussed and the importance of additional perturbations by polar groups is stressed.

TL;DR: The results indicate that weak charge transfer type bands might exist due to electron transfer from the carboxylate ion to the Schiff base and that the intense (π, π*) band in the visible spectrum might acquire a significant degree of charge transfer character.

TL;DR: A unified view of the photochemical part of the visual process is presented and it is proposed that both conformational changes and changes in intermolecular interactions in the sequence that leads from rhodopin through batho-lumi- and meta-I to meta-II- rhodopsin have to be considered in order to elucidate the mechanism of theVisual process.