-
1
-
-
85034930098
-
-
Reviews on various aspects of polar solvation dynamics can be found in Refs. 2–4. Reviews concerning dynamical solvent effects are provided in Refs. 6-8.
-
-
-
-
18
-
-
85034929754
-
-
Actually, the early continuum treatments in Refs. 15 and 16 did consider inertial solvent motions but this aspect of these continuum theories was largely ignored in later work.
-
-
-
-
54
-
-
84950551588
-
-
See AIP document no. PAPS JCPSA-103-3038-2 for 2 pages of the supplementary table (2 pages) containing the coordinates and charges of coumarin 153 used in these simulations. Order by PAPS number and journal reference from American Institute of Physics, Physics Auxiliary Publication Service, Carolyn Gehlbach, 500 Sunnyside Boulevard, Woodbury, New York 11797-2999. Fax: 516-576-2223, e-mail: janis@aip.org. The price is $1.50 for each microfiche (98 pages) or $5.00 for photocopies of up to 30 pages, and $0.15 for each additional page over 30 pages. Airmail additional. Make checks payable to the American Institute of Physics.
-
-
-
-
58
-
-
85034916182
-
AMPAC 5.0, ©
-
Semichem, 7128 Summit, Shawnee, KS 66216
-
(1994)
-
-
-
61
-
-
84986531941
-
The value of 1.43 was the one originally recommended in Ref 46. A revised value of 1.35 is recommended
-
but this value was not used here
-
(1992)
J. Comput. Chem.
, vol.13
, pp. 749
-
-
Merz, K.M.1
-
67
-
-
84950551589
-
-
These standard methods are described (along with literature references) in M. P. Allen and D. J. Tildesley, Computer Simulation of Liquids (Clarendon, Oxford)
-
(1987)
-
-
-
68
-
-
84950551586
-
-
The two frequencies do not agree exactly even in the acetonitrile case because the exponential functions in Eq. (7), which do not have the correct zero slope at t=0, affect the fit slightly.
-
-
-
-
69
-
-
85034925065
-
-
However, one should note that the fitted frequency is not devoid of meaning. This effective solvation frequency can be derived from an effective average moment of inertia for the molecule. For simple solutes (such as [formula omitted]) this frequency characterizes (in an average sense) the decay of the inertial component of [formula omitted] just as in the simpler case of acetonitrile. See Ref. 2(b).
-
-
-
-
70
-
-
85034914748
-
-
Some of the differences in small solutes arise due to differences solute dynamics rather in differences in the solvent. See Ref. 23.
-
-
-
-
74
-
-
84950551585
-
-
In Ref. 23 the charge differences used for calculating [formula omitted] differed from those used here. The earlier values were obtained from MNDO calculations using very limited configuration interaction (a [formula omitted] configuration space). These values are expected to much less reliable than present values.
-
-
-
-
75
-
-
85034929245
-
-
In determining these charge differences we have applied the recommended 1.43 scaling factor to the MNDO values (see Ref. 48). If we had not done so, the Stokes shift would be smaller than that observed.
-
-
-
-
77
-
-
0001652067
-
-
We note that very few comparisons of this sort have been made previ ously. The good agreement shown in the acetonitrile case is noteworthy, since it is not always the case that “off-the-shelf” potential functions yield reliable results for such solute dynamics. See, for example
-
(1988)
J. Phys. Chem.
, vol.92
, pp. 4811
-
-
Chen, L.X.-Q.1
Engh, R.A.2
Fleming, G.R.3
-
79
-
-
85034922525
-
-
In the case of acetonitrile, the longitudinal response function was deter mined by Edwards et al. (Ref. 42) directly from simulation via Eqs. (10) and (11). The curve shown here corresponds to the smallest k-vector function ([formula omitted]) given in Fig. 4 of Ref. 42. In the case of methanol, we computed [formula omitted] from the dielectric response of the simulation model according to Eq. (12). For the latter function we used the transverse dielectric response [formula omitted] determined directly by Ladanyi and co workers (Ref. 65) for the smallest value of k simulated ([formula omitted]). The computed longitudinal response function is indistinguishable from the nor malized [formula omitted] determined directly by these authors over the range displayed in Fig. 4 of their Ref. 65. In both simulations the system size was thought to be large enough that these results determined for the small est wavevectors accessible to simulation should be quite close to the [formula omitted] limit.
-
-
-
-
81
-
-
0000443408
-
-
The experimental longitudinal response curves were determined from Eq. (12) using experimental [formula omitted] data. In order to properly capture the inertial components of the dielectric response we simultaneously fit a combination of both microwave and FIR data. In the case of acetonitrile the experimental data are from (MW)
-
(1991)
J. Phys. Chem.
, vol.95
, pp. 7055
-
-
Firman, P.1
Marchetti, A.2
Eyring, E.M.3
Petrucci, S.4
-
86
-
-
85034925677
-
-
Ladanyi has noted (private communication) that quantum mechanical effects not present in these classical simulations can also affect the high-frequency components of the solvation response. Such effects are only expected to be important for hydroxylic solvents which have librational modes with frequencies higher than [formula omitted] Approximate correction of the classical [formula omitted] leads to an enhanced role of the fastest components of the solvation response and which would serve to counteract the effects of electronic polarizability.
-
-
-
-
87
-
-
0346389374
-
-
The spin relaxation of a quadrupolar nucleus depends on this time-correlation function of the electric field gradient ([formula omitted] where V is the electrical potential). There have been a number of recent simulation studies that have examined this dynamics in polar solvents and the results are comparable to what we find here. See
-
(1994)
J. Phys. Chem.
, vol.98
, pp. 12108
-
-
Odelius, M.1
-
91
-
-
36549097925
-
-
However, Bagchi and co-workers have emphasized the point that, depending on the relative importance of translational and rotational solvent motions, the response time may not always show a monotonic change with wave vector. See and Refs. 4
-
(1989)
J. Chem. Phys.
, vol.91
, pp. 2594
-
-
Chandra, A.1
Bagchi, B.2
-
94
-
-
18344362329
-
-
who made a crude calculation of the effect of diffusive rotation on the dipole solvation and the recent work of who considered how translational motion of a light ion affects its solvation.
-
(1994)
Chem. Phys.
, vol.183
, pp. 207
-
-
Roy, S.1
Bagchi, B.2
-
96
-
-
84950551580
-
-
This approximation is in the spirit of cumulant approximations for rotational tcfs as described by R. M. Lynden-Bell, in Molecular Liquids: Dynamics and Interactions edited by A. J. Barnes, W. J. Orville-ThomasJ. arwood (Reidel, Dordrecht)
-
(1984)
, pp. 501-508
-
-
-
98
-
-
84946649831
-
From NMR measurements of benzene in dilute solutions
-
we estimate that [formula omitted] lies in the range [formula omitted] ps for a variety of solvents. Thus the simulation result for rotation of benzene in acetonitrile (3.1 ps) appears to be a reasonable value. The simulated value of 1.1 ps for methanol solvent seems unrealistically low. (The NMR estimate in methanol is 2.0 ps).
-
(1980)
Mol. Phys.
, vol.39
, pp. 493
-
-
Tanabe, K.1
Hiraishi, J.2
-
100
-
-
84950551574
-
-
The symbol [formula omitted] is used to distinguish this polarizability from the usual meaning of the term polarizability (α) as the proportionality constant be tween an induced dipole moment and an external electric field. The two quantities are simply related by [formula omitted] where l is the bond length of the diatomic. In the present systems it happens that the values of [formula omitted] given here in atomic units are nearly equal to the values of α in the common units of [formula omitted]
-
-
-
-
107
-
-
36449002318
-
-
A simple model for the solvation frequency in the case of charge solvation is developed in Ref. 17. From that analysis one observes that the solvation mass is a quantity which incorporates both the inertial properties of solvent molecules as well as a description of the weighting factors that translate between the motions of individual molecules and the collective solvation coordinate. See also for a helpful discussion of the meaning of the solvation frequency
-
(1994)
J. Chem. Phys.
, vol.100
, pp. 6700
-
-
Stratt, R.M.1
Cho, M.2
-
108
-
-
84950551575
-
-
The interpretation here is quite similar to our previous interpretations of how the rate of solvation is related to solvent polarity (Ref. 17). For sufficiently polar solvents [formula omitted] is nearly independent of solvent polarity while [formula omitted] decreases as the solvent polarity increases. Although the roles of [formula omitted] and [formula omitted] are reversed, the underlying reasons for the dependence on solvent polarity are the same as those discussed here with respect to for solute polarizability. In the former case the changing relationship between solvent molecule motions and the solvation coordinate (as reflected in [formula omitted]) means that for constant fluctuation magnitude (constant [formula omitted]) the smaller [formula omitted] the less single-particle motion is needed to relax the solvation coordinate and therefore the faster the solvation response.
-
-
-
-
110
-
-
84950551576
-
-
Mean polarizabilities are from tabulations in C. G. Gray and K. E. Gubbins, Theory of Molecular Fluids (Clarendon, Oxford)
-
(1984)
-
-
-
111
-
-
1642549173
-
-
and molecular volumes were computed from van der Waals increments
-
(1970)
J. Chem. Ed
, vol.47
, pp. 261
-
-
Edwards, J.T.1
-
113
-
-
84950551577
-
-
It is not unreasonable to suppose that in cases where the charge separation within [formula omitted] is much greater than in [formula omitted] the polarizability might be lowered in the excited state.
-
-
-
-
114
-
-
85034930173
-
-
Very recent studies by Kim and co-workers have shown that in fact non linear effects may be enhanced by the presence of large solute polarizabil ities. (See Ref. 89)
-
-
-
-
115
-
-
84950551583
-
-
The two systems were not quite identical in that we employ a 12-site representation of benzene whereas the comparable calculations in Ref. 21 used a 6-site representation.
-
-
-
-
117
-
-
85034915426
-
-
This estimate is our own made from visual comparisons of solvation response functions in the fully polarizable and the semipolarizable models of Ref. 39 (provided by P. Callis in a private communication.)
-
-
-
|
