The Nature of Hydrogen Bond: New Iinsights Into Old Theories
Biserka Kojić-Prodić* and Krešimir Molčanov
Rudjer Bošković Institute Zagreb, Croatia
* Corresponding author: E-mail: email@example.com
Almost hundred years old concepts on hydrogen bonding are brought into light to be compared to the contemporary views and theories. The first findings were based on qualitative grounds and relied upon observations of simple experiments and very much on human imagination. It is a challenge to contrast the old and new views and to see if they could be verified or revised. Over the last decades there has been tremendous development of methods for structure elucidation and many hydrogen bonded molecular structures were determined and deposited in structural data bases. The structural aspect of hydrogen bond in the solid state is well defined. However, the knowledge of hydrogen bonded structures in the liquid state is still limited. Studies on hydrogen bond dynamics, which are in progress, with new experimental methods will help to better understand processes in solutions. In many systems the functioning of hydrogen bonding at atomic level has been still an enigma. In biological reactions the proton transfer is a key issue of acid-base enzyme catalysis and ribozymic function, transport reactions such as “water wires” functioning through the membrane protein channels and photosynthetic reaction centres. The paramount example for the unique role of the proton in specificity and rates is the storage life’s genetic information: hydrogen bonds define the complementarities of G with C and A with T whereas the hydrogen transfer controls the genetic mutations. Ultra-fast time-resolved spectroscopies of hydrogen bonds and proton-transfer processes accompanied by very sophisticated theoretical frameworks such as multidimensional quantum dynamics and combined quantum mechanics/molecular mechanics are offering new insights into functioning of hydrogen bond.
Keywords: Hydrogen bond-old and new concepts, historical aspects of hydrogen bond