Vibrationally coherent photochemistry in the femtosecond primary event of vision

Journal Article · Fri Oct 21 04:00:00 EDT 1994 · Science

DOI:https://doi.org/10.1126/science.7939680· OSTI ID:86543

Wang, Q; Shank, C V; Schoenlein, R W ^[1]; Peteanu, L A; Mathies, R A ^[2]

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1. Lawrence Berkeley Lab., CA (United States)
2. Univ. of California, Berkeley, CA (United States)

Femtosecond pump-probe experiments reveal the impulsive production of photoproduct in the primary event in vision. The retinal chromophore of rhodopsin was excited with a 35-femtosecond pulse at 500 nanometers, and transient changes in absorption were measured with 10-femtosecond probe pulses. At probe wavelengths within the photoproduct absorption band, oscillatory features with a period of 550 femtoseconds (60 wavenumbers) were observed whose phase and amplitude demonstrate that they are the result of nonstationary vibrational motion in the ground state of the photoproduct. The observation of coherent vibrational motion of the photoproduct supports the idea that the primary step in vision is a vibrationally coherent process and that the high quantum yield of the cis {yields} trans isomerization in rhodopsin is a consequence of the extreme speed of the excited-state torsional motion.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 86543
• Journal Information: Science, Journal Name: Science Journal Issue: 5184 Vol. 266; ISSN 0036-8075; ISSN SCIEAS
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
CONFORMATIONAL CHANGES
IN VITRO
PHOTOCHEMISTRY
QUANTUM EFFICIENCY
RHODOPSIN
VIBRATIONAL STATES
VISION