C-HMIDLINE HORIZONTAL ELLIPSISS hydrogen bonding interactions

The short C-HMIDLINE HORIZONTAL ELLIPSISS contacts found in available structural data for both small molecules and larger biomolecular systems suggest that such contacts are an often overlooked yet important stabilizing interaction. Moreover, many of these short C-HMIDLINE HORIZONTAL ELLIPSISS contacts meet the definition of a hydrogen bonding interaction. Using available structural data from the Cambridge Structural Database (CSD), as well as selected examples from the literature in which important C-HMIDLINE HORIZONTAL ELLIPSISS contacts may have been overlooked, we highlight the generality of C-HMIDLINE HORIZONTAL ELLIPSISS hydrogen bonding as an important stabilizing interaction. To uncover and establish the generality of these interactions, we compare C-HMIDLINE HORIZONTAL ELLIPSISS contacts with other traditional hydrogen bond donors and acceptors as well as investigate how coordination number and metal bonding affect the preferred geometry of interactions in the solid state. This work establishes that the C-HMIDLINE HORIZONTAL ELLIPSISS bond meets the definition of a hydrogen bond and serves as a guide to identify C-HMIDLINE HORIZONTAL ELLIPSISS hydrogen bonds in diverse systems.

Automated summary

The study demonstrates that C-H midline bonds are often overlooked but important stabilizing interactions, meeting the definition of hydrogen bonding. By comparing with traditional hydrogen bond donors and acceptors, as well as investigating the effect of metal bonding, the generality of C-H midline hydrogen bonding can be established and used for identification in diverse systems.