Category Archives: Weak Hydrogen Bonds

Non-covalent interactions

We published in Chemistry: A European Journal a Minireview on rotational studies of non-covalent interactions, which appeared in the Reviews Showcase section of the Journal. In the article, entitled “The Hydrogen Bond and Beyond: Perspectives for Rotational Investigations of Non‐Covalent Interactions“, we emphasize how the new broadband microwave techniques have boosted the possibilities for analyzing larger clusters and weaker interactions with rotational resolution.

The forest of non-covalent interactions has more trees than expected. Read the minireview to check out why.

Aniline trimer

A rotational investigation of the aniline trimer was published in Angewandte Chemie. The work, done in collaboration with Cristobal Pérez (Hamburg) and Brooks Pate (Virginia), found three isomers of the aniline trimer and two isomers of the monohydrated dimer. The trimer is more complex than the analogue phenol trimer, where the stronger O-H···O interaction produce a single (symmetric) isomer. In the aniline trimer, stabilized by N-H···N and N-H···Pi, interactions one of the observed species is also a symmetric rotor.

The figure shows the symmetric isomer of the aniline trimer, observed in a jet expansion.

New PCCP cover

New cover on PCCP! A work in collaboration with the Brooks H. Pate group in Virginia was featured as cover of PCCP in the July 28th issue. We show how transient chirality in the anesthetic sevoflurane is stabilized on formation of the dimer, as two different diastereoisomers (homochiral: left/left or right/right; heterochiral: left/right or right/left) are formed and distinguished by their spectral rotational signature. The structure of the dimers were fully resolved usign isotopic information, rendering information on the weak hydrogen bonds stabilizing the cluster.

PCCP cover sevo2sevo2

PCCP cover

A work on the intermolecular cluster pyridine-methane in collaboration with the group of  Walther Caminati has been chosen as cover of PCCP. Methane behaves in the complex as a noble gas, binding on top of the aromatic ring. This T-shape structure contrasts with the in-plane structure of other pyridine clusters involving halomethanes.



A work in collaboration with the Pate group in Virginia examined the weakly-bound cluster of sevoflurane···benzene ans was published in Angewandte Chemie. The primary interaction is a relatively strong C-H···pi hydrogen bond. The presence of additional C-H···F weak interactions hinders the six-fold symmetric internal rotation of benzene around sevoflurane. This is probably the first time that such a V6 barrier has been determined in a intermolecular complex.