Study of H-bonded cyclic dimer of organic linker 5-Bromoisophthalic acid by DFT and vibrational spectroscopy

5-Bromoisophthalic acid is a potential organic linker in Hydrogen-bonded Organic Frameworks (HOFs). Its H-bonding properties would be determinants, among others, in optimizing the reversible structural transformations, dissolution and re-crystallization, low densities and high porosity. In the present study, a DFT cyclic dimer model computed at B3LYP/cc-pVDZ level based on inter-molecular-O-H center dot center dot center dot O bonding has been proposed. The proposed cyclic dimer model fits observed vibrational IR and Raman spectral features. Computed chemical shifts for the protons in 5-Bromoisophthalic acid monomer agree with the experimental H-1 NMR values in d(6)-DMSO which dissociates the cyclic dimer into monomers. In the O-H (Acceptor) center dot center dot center dot O- (Donor) bonding, NBO, AIM and NCI calculations have provided a satisfactory electronic characterization based on orbital overlaps, electron density and associated topological, non-covalent interaction properties consistent with structural and vibrational analysis. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

5-Bromoisophthalic acid is a potential organic linker in Hydrogen-bonded Organic Frameworks (HOFs), with its H-bonding properties playing a crucial role in optimizing structural transformations, dissolution, re-crystallization, density, and porosity.