An Efficient Screen for Determining Solid-State Hydrogen-Bonding Patterns in Carboxylic Acids

Simple crystalline keto carboxylic acids adopt hydrogen-bonding modes that are either intra- or inter-molecular, with the latter, far larger, class including carboxyl dimers and carboxyl-to-ketone catemers; it is demonstrated that symmetry-based differences between solid-state infrared and Raman spectra may be reliably used to differentiate those with dimeric H-bonding from those with noncentrosymmetric H-bonding patterns.