Water tetramer

Cruzan J D, Braly L B, Liu K, Brown M G, Loeser J G and Saykally R J 1996 Quantifying hydrogen bond oooperatively in water VRT speotrosoopy of the water tetramer Science 271 59-62... 

D. Sabo, Z. Bacic, S. Graf, and S. Leutwyler, Four dimensional model calculation of torsional levels of cyclic water tetramer. J. Chem. Phys. 109, 5404 5419 (1998). 

Fig. 18 2D hydrogen bonded network structure of [(DMF)(CTV)]2(H20)4(o-carborane)] 35 with water tetramers hydrogen bonding to CTV molecules [82]... 

Koehler JEH, Lesyng B, Saenger W (1987) Cooperative effects in extended hydrogen bonded systems involving OH-groups. Ab initio studies of the cyclic S4 water tetramer. J Comput Chem 8 1090-1098... 

Figure 5.24 Cyclic water tetramer with symmetry.

W. Shibata, and K. Seff, Terahertz Laser Vibration-rotation-tunneling Spectroscopy of the Water Tetramer. J. Phys. Chem. B, 1997, 101, 9022-9031. 

Analysis of the many-body interactions in tetramers suggests that benzene is actively involved in a collective H-bonding network in these clusters as well. For example, as shown in Fig. 5.2, several energetically low-lying benzene-water tetramers prefer cyclic structures that are similar to the structure of the water tetramer, and exhibit significant stabilizing many-body energies. 

Figure 3. Same as figure 1 except for the concerted hydrogen atom transfer in the water tetramer (see diagram 2).

Figure 4. Comparison of potential energy along the minimum energy path and relative ground-state adiabatic potential for the concerted hydrogen atom transfer in the water trimer (dashed curves) and water tetramer (solid curves), using BAC-MP4 calculations.

Other reported phosphonate cavitands include a tefra-methyl phosphonate that has been shown to template, via its rigidly preorganized P = O acceptor groups, a unique cyclic water tetramer of C4 symmetry [208]. The same host has also been shown to bind zinc, barium, and calcium salts in a dimeric 2 1 host-guest complex... 

Quantifying Hydrogen Bond Cooperativity in Water VTR Spectroscopy of the Water Tetramer. 

Cruzan, J. D., Braly, L. B., Brown, M. G., Loeser, J. G., Saykally, R. J. (1996a). Quantifying hydrogen bond cooperativity in water VRT spectroscopy of the water tetramer. Science, 271, 59-62. 

Figure 3 Some of the. stationary points on the water tetramer potential energy. surface, (udud), with 4 symmetry. i.s the global minimum...

At the present time the rearrangement dynamics of the water tetramer are not as well understood as those of the trimer, as should be evident from the above discussion. However, it seems unlikely that a new direct degenerate rearrangement between versions of the (udud) global minimum will be found to account for the small tunneling splittings observed experimentally. Instead, some combination of synchronous and asynchronous quadruple flips is probably responsible, but fiirther calculations are needed to clarify the situation. 

Recently, both the MK and RVS analyses have been extended to many-body complex systems. This allows the computation of many-body effects on each energy component within the MK of RVS analyses, since rigorously only es is pair-wise additive. In the case of water trimers and tetramers it was found that polarization and charge transfer are the dominant components in the three-body energy terms. The four body term in the water tetramer was found to be negligible. 

J. Ceponkus, P. Uvdal, B. Nelander, Water tetramer, pentamer, and hexamer in inert matrices. J. Phys. Chem. A 116(20), 4842 850 (2012)... 

Figure 5. Correlation Junction of the O-H stretching normal mode of the water tetramer at zero temperature. The real and imaginary parts are shown as solid circles and hollow squares, respectively.

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