Studies of Hydrogen Bonding

Most crystallographers have been asked the following question how do you know that the conformation you observe in the crystal structure is the same as the solution conformation Although the question is obviously flawed (there is no single solution 

The influence of environmental effects can be formalized as follows Suppose that we measure the value of a particular molecular parameter (say, the O-N-O valence angle in nitro groups) in a series of crystal structures. The values observed in the /th structure, can be expressed as  

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Costain C C and Srivastava G P 1961 Study of hydrogen bonding miorowave speotra of CF3COOH-HCOOH J. Chem. Phys. 35 1903-4... 

WE Reiher III. Theoretical Studies of Hydrogen Bonding. Ph.D. Thesis, Harvard University, 1985. 

Luck, W. A. P. Infrared Studies of Hydrogen Bonding in Pure Liquids and Solutions in Water — a Comprehensive Treatise, (ed. Franks, F.), Vol. 2, chapter 4, New York, Plenum Press 1973... 

Sung C.S.P. and Schneider N.S., Infrared studies of hydrogen bonding in toluene diisocyanate based polymethylene, Macromolecules, 8, 68, 1975. 

Rablen, P. R. Lockman, J. W. Jorgensen, W. L. Ah initio study of hydrogen-bonded complexes of small organic molecules with water. J. Phys. Chem. A 1998, 102, 3782-3797. 

Civalleri, B., Garrone, E., Ugliengo, P., 1997, Density Functional Study of Hydrogen-Bonded Systems Energetic and Vibrational Features of Some Gas-Phase Adducts of Hydrogen Fluoride , J. Mol. Struct. (Theochem), 419, 227. 

Latajka, Z., Bouteiller, Y., 1994, Application of Density Functional Methods for the Study of Hydrogen-Bonded... 

Scheiner, S. (1994) Ab-initio studies of hydrogen bonds the water dimer paradigm, Annu. Rev. Phys. Chem., 45,23-56. 

Latajka, Z., and Y. Bautellier. 1994. Application of density functional methods for the study of hydrogen-bonded systems The hydrogen flouride dimer. J. Chem. Phys. 101, 9793. 

Morokuma, K. 1971. Molecular orbital studies of hydrogen bonds. III. C = O- H — O hydrogen bond in H2CO- H20 and H2CO- -2H20. J. Chem. Phys. 55 1236. 

A. Fujii, S. Enomoto, M. Miyazaki, and N. Mikami, Morphology of protonated methanol clusters An infrared spectroscopic study of hydrogen bond networks of H+(CH30H)n (n 4 15). 

M. A. Czarnecki, Near infrared spectroscopic study of hydrogen bonding in chiral and racemic octan 2 ol. J. Phys. Chem. A 107, 1941 1944 (2003). 

Much of the impetus for the study of hydrogen bonded network structures of 24 and bipy or other linear N-donor ligands has come from the desire to perform time-resolved crystallographic studies of photoactive guest species embedded within the network as a guest [58,62,63]. Embedding a photoactive species within a network structure effectively dilutes it in the solid state. The advantages of this include improved uniformity of illumination of the crystal, less photons are... 

The complex [Ru(tpy)Cl3] binds to DNA, and is active as a cytostatic in L1210 leukemia cells. Its activity lies between those of cisplatin and carboplatin. Model complexes [Ru(tpy)L(H20)] + in which L = 9-ethylguanine or 9-methylhypoxanthine, have been prepared and characterized using NMR spectroscopy. " Proton NMR spectroscopy has been applied to a study of hydrogen bonding between 2, 3 -isopropylidine adenosine and [Ru(tpy)2] derivatives bearing a thymine group. 

Kyogoku Y, Lord RC, Rich A. An infrared study of hydrogen bonding between adenine and uracil derivatives in chloroform solution. J Am Chem Soc 1967a 89 496-504. 

Studies of hydrogen bonding and iodine complexation on alkyl-substituted oxetanes have shown that 2-alkyl and 2,2-dialkyl substitution enhances the electron donor ability, while 3,3-dialkyl substitution substantially diminishes it. This has been attributed to a decrease in the bond angle strain at the oxygen atom, due to a Thorpe-Ingold effect at C-3, since the effect increases with the size of the alkyl substituent at that position (71BSF4576). 

At this point it has to be mentioned that ab initio calculations at the HF level are not ideal for the study of hydrogen-bonded... 

THE STUDY OF HYDROGEN BONDS BY NEUTRON DIFFRACTION G. E. Bacon... 

The individual examples we have considered thus far will serve to illustrate the application of the proton magnetic resonance method to studies of hydrogen bonding. In conclusion we may summarize briefly a few general observations on the technique itseif and how it compares with other methods, as for example, infiared absorption measurements. 

Dr. Schneider s paper has given an introduction to the subject of the nuclear resonance study of hydrogen bonding, which will not be repeated here. Our initial aim was to study molecular complexes in aqueous solution, with particular emphasis on complexes of biological importance. It soon became apparent that the phenomena were so complex that a fundamental study of hydroxyl-type hydrogen bonds in simple molecules was first required. 

In conclusion, the studies completed illustrate the types of information which can be obtained from matrix isolation studies of hydrogen bonding systems. It is clear that this technique offers a new tool for the infrared study of the hydrogen bond. 

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