Login
- Titel:
Vibrational echo correlation spectroscopy: a new probe of hydrogen bond dynamics in water and methanol
- Autor(en):
- Asbury, John B.; Steinel, Tobias; Fayer, M. D.
- Abstract:
- Multidimensional vibrational echo correlation spectroscopy with full phase resoln. is used to measure hydrogen bond dynamics in water and methanol. The OD hydroxyl stretches of methanol-OD oligomers in CCl4 and HOD in H2O are studied using the shortest mid-IR pulses (< 45 fs, < 4 cycles of light) produced to date. The pulses have sufficient spectral bandwidth to span the very broad (> 400 cm-1 ) spectrum of the 0-1 and 1-2 vibrational transitions. Hydrogen bond population dynamics are extricated with exceptional detail in MeOD oligomers because the different hydrogen-bonded species are spectrally distinct. The exptl. results along with detailed calcns. indicate the strongest hydrogen bonds are selectively broken through a non-equil. relaxation pathway following vibrational relaxation of the hydroxyl stretch. Following hydrogen bond breaking, the broken MeOD oligomers retain a detailed structural memory of the prior intact hydrogen bond network. The correlation spectra are also a sensitive probe of the structural fluctuations in water and provide a stringent test of water models that are widely used in simulations of aq. systems. The anal. of the 2D band shapes demonstrates that different hydrogen-bonded species are subject to distinct (wavelength-dependent) ultrafast (∼ 100 fs) local fluctuations and essentially identical slower (0.4 ps and ∼ 2 ps) structural rearrangements. Observation of wavelength-dependent dynamics demonstrates that std. theor. approaches assuming Gaussian fluctuations cannot adequately describe water dynamics. [on SciFinder(R)]
- Stichworte:
- Hydrogen bond IR radiation Molecular vibration (multidimensional vibrational echo correlation spectroscopy with full phase resoln. to measure hydrogen bond dynamics in water and methanol) water methanol hydrogen bond dynamics vibrational echo correlation spectroscopy
- Kongresstitel:
- CAN 143:335001 73-3 Optical, Electron, and Mass Spectroscopy and Other Related Properties Department of Chemistry, Stanford University, Stanford, CA, USA. Conference 56-23-5 (Carbon tetrachloride); 67-56-1 (Methanol); 7732-18-5 (Water) Role: PRP (Properties) (multidimensional vibrational echo correlation spectroscopy with full phase resoln. to measure hydrogen bond dynamics in water and methanol)
- Zeitschriftentitel:
- Femtosecond Laser Spectrosc.
- Jahr:
- 2005
- Seitenangaben Beitrag:
- 167-196
- Volltext / DOI:
- doi:10.1007/b101192
BibTeX