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Volumn 113, Issue 8, 2009, Pages 2428-2435

Why water reorientation slows without iceberg formation around hydrophobic solutes

Author keywords

[No Author keywords available]

Indexed keywords

DYNAMICS; HYDROGEN; MOLECULAR DYNAMICS; MOLECULES; NUCLEAR MAGNETIC RESONANCE; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY;

EID: 65249157127     PISSN: 15206106     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp809521t     Document Type: Article
Times cited : (347)

References (63)
  • 1
    • 38849196324 scopus 로고    scopus 로고
    • Ball, P. Chem. ReV. 2008, 108, 74-108.
    • Chem. Re , vol.2008 , Issue.108 , pp. 74-108
    • Ball, P.1
  • 2
    • 26944481188 scopus 로고    scopus 로고
    • Chandler, D. Nature 2005, 437, 640-647.
    • (2005) Nature , vol.437 , pp. 640-647
    • Chandler, D.1
  • 20
    • 26444443012 scopus 로고    scopus 로고
    • Buchanan, P.; Aldiwan, N.; Soper, A. K.; Creek, J. L.; Koh, C. A. Chem. Phys. Lett. 2005, 415, 89.
    • Buchanan, P.; Aldiwan, N.; Soper, A. K.; Creek, J. L.; Koh, C. A. Chem. Phys. Lett. 2005, 415, 89.
  • 21
    • 0036450690 scopus 로고    scopus 로고
    • Our simulations of dilute TMAO solutions yield a second-order reorientation time of the TMAO NsO axis of 14 ps, consistent with the first-order Debye relaxation time of 30 ps measured experimentally: Shikata, T, Itatani, S J. Solution Chem. 2002, 31, 823-844. The NO anisotropy thus decays by more than 50% on the 0-10-ps interval
    • Our simulations of dilute TMAO solutions yield a second-order reorientation time of the TMAO NsO axis of 14 ps, consistent with the first-order Debye relaxation time of 30 ps measured experimentally: Shikata, T.; Itatani, S J. Solution Chem. 2002, 31, 823-844. The NO anisotropy thus decays by more than 50% on the 0-10-ps interval.
  • 29
    • 0036751377 scopus 로고    scopus 로고
    • Patil, K. J.; Sargar, A. M.; Dagade, D. H Indian J. Chem. A: Inorg., Bio-inorg., Phys., Theor. Anal. Chem. 2002, 41, 1804.
    • Patil, K. J.; Sargar, A. M.; Dagade, D. H Indian J. Chem. A: Inorg., Bio-inorg., Phys., Theor. Anal. Chem. 2002, 41, 1804.
  • 33
    • 84906388720 scopus 로고    scopus 로고
    • In a 4 m aqueous TMAO solution, the experimental water translational diffusion constant is 0.54 × 10-5 cm2 s-1;26 the rigid model leads to a 1.0 × 10-5 cm2 s-1 value, in better agreement than the flexible model, which yields a diffusion constant of 1.5 × 10-5 cm2 s-1.
    • In a 4 m aqueous TMAO solution, the experimental water translational diffusion constant is 0.54 × 10-5 cm2 s-1;26 the rigid model leads to a 1.0 × 10-5 cm2 s-1 value, in better agreement than the flexible model, which yields a diffusion constant of 1.5 × 10-5 cm2 s-1.
  • 41
    • 84906388721 scopus 로고    scopus 로고
    • These retardation factors were determined from the anisotropy decay times for water OH bonds initially next to each of the solute sites. These decay times are approximations, as the residence time of water next to these sites is comparable to the anisotropy decay value
    • These retardation factors were determined from the anisotropy decay times for water OH bonds initially next to each of the solute sites. These decay times are approximations, as the residence time of water next to these sites is comparable to the anisotropy decay value.
  • 44
    • 84906360335 scopus 로고    scopus 로고
    • The reactant state is defined by the existence of a H-bond with the initial partner, without any restriction on the new partner location. The presence of the hydrophobic group, therefore, does not impose any limitation on the accessible reactant states
    • The reactant state is defined by the existence of a H-bond with the initial partner, without any restriction on the new partner location. The presence of the hydrophobic group, therefore, does not impose any limitation on the accessible reactant states.
  • 47
    • 84906388722 scopus 로고    scopus 로고
    • However, next to an extended hydrophobic surface, the H-bond arrangement is no longer clathrate-like,2,5 and our model should be extended to include the OH bonds pointing toward the surface.
    • However, next to an extended hydrophobic surface, the H-bond arrangement is no longer clathrate-like,2,5 and our model should be extended to include the OH bonds pointing toward the surface.
  • 48
    • 84906374626 scopus 로고    scopus 로고
    • In ref 11, a steric factor associated with the attainment of the fivecoordinate transition state (originally found in ref 34 and found again in the present work) was invoked to explain the immobilization. However, in dilute solutions, the transition-state excluded fraction cannot exceed 1/2, and the maximum slowdown is 2, very far from immobilization
    • In ref 11, a steric factor associated with the attainment of the fivecoordinate transition state (originally found in ref 34 and found again in the present work) was invoked to explain the immobilization. However, in dilute solutions, the transition-state excluded volume fraction cannot exceed 1/2, and the maximum slowdown is 2, very far from immobilization.
  • 50
    • 84906403280 scopus 로고    scopus 로고
    • The entropic factor was also assumed to be temperature-independent through its microcanonical expression in eq 3
    • The entropic factor was also assumed to be temperature-independent through its microcanonical expression in eq 3.
  • 51
    • 84906388540 scopus 로고    scopus 로고
    • See within; for TMAO, the more pronounced slowdown is around the hydrophilic head (∼2.4) rather than around the hydrophobic moiety (∼1.5).
    • See within; for TMAO, the more pronounced slowdown is around the hydrophilic head (∼2.4) rather than around the hydrophobic moiety (∼1.5).
  • 61
    • 84906360334 scopus 로고    scopus 로고
    • Our simulation anisotropies are scaled to compensate for the different initial, 200-fs librational decays measured by the experiments and the simulations, which has no consequence for the remaining analysis
    • Our simulation anisotropies are scaled to compensate for the different initial (?200-fs) librational decays measured by the experiments and the simulations, which has no consequence for the remaining analysis.
  • 62
    • 84906388718 scopus 로고    scopus 로고
    • The OD stretch vibrational lifetime was experimentally11 confirmed to be unaffected by TMAO, which excludes a bias (shown for halides35) of ultrafast anisotropy measurements toward a slower reorientation.
    • The OD stretch vibrational lifetime was experimentally11 confirmed to be unaffected by TMAO, which excludes a bias (shown for halides35) of ultrafast anisotropy measurements toward a slower reorientation.
  • 63
    • 84906374621 scopus 로고    scopus 로고
    • As explained at the end of section IV.b, at high concentration, the anisotropy decay is no longer strictly monoexponential because of the broad distribution of excluded here, we use the monoexponential approximation to compare the retardation factors from the simulations and the TSEV model
    • As explained at the end of section IV.b, at high concentration, the anisotropy decay is no longer strictly monoexponential because of the broad distribution of excluded volumes; here, we use the monoexponential approximation to compare the retardation factors from the simulations and the TSEV model.


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