Hydrogen Bonding Rules

After an extensive survey of intermolecular contacts in CSD, Etter and coworkers [25] presented the following empirical rules for determining preferred hydrogen bonding modes in organic solids  

All good proton donors and acceptors are used in hydrogen bonding. 

Six-membered-ring intramolecular hydrogen bonds form in preference to intermolecular hydrogen bonds. 

The best proton donors and acceptors remaining after intramolecular hydrogen bond formation form intermolecular hydrogen bonds to one another. 

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Egholm M., Buchardt O., Christensen L., Behrens C., Ereier S.M., Driver D.A., Berg, R. H., Kim, S.K., Nor-DEN B., Nielsen, P.E. PNA hybridizes to complementary oligonucleotides obeying the Watson—Crick hydrogen-bonding rules. Nature 1993, 365 566-568. 

Table I. Hydrogen-bond Rules for Organic Compounds...

Egholm M, Buchardt O, Christensen L, Behrens C, Freier SM, Driver DA, et al. PNA Hybridizes to Complementary Oligonucleotides Obeying the Watson-Crick Hydrogen Bonding Rules. Nature 1993 365 566-8. 

RNA and DNA are held together by the conventional Watson-Crick base pairing hydrogen bonding rules. There is no covalent bond. 

If the sequence of a codon on the mRNA is 5 -AUG-3, what will the sequence of the anticodon be Remember that the hydrogen bonding rules require antiparallel strands. It is easiest to write the anticodon first 3 —> 5 and then reverse it to the 5 —> 3 order. 

Egholm M, et al. (1993). PNA hybridizes to complementary oligonucleotides obeying the Watson-Crick hydrogen-bonding rules. Nature. 365 566-568. 

Etter [13] proposed hydrogen bonding rules in molecular crystals containing N-H donors and C=0 acceptors ... 

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