A structural comparative study of charge transfer compounds: Synthesis, crystal structure, IR, Raman-spectroscopy, DFT computation and hirshfeld surface analysis

• Published in: Journal of molecular structure Vol. 1192; pp. 132 - 144
• Main Authors: Falek, Wahiba, Benali-Cherif, Rim, Golea, Lynda, Samai, Salima, Benali-Cherif, Nourredine, Bendeif, El-Eulmi, Daoud, Ismail
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.09.2019; Elsevier
• Subjects: Charge transfer compounds; DFT calculation; Hirshfeld surface analysis; Intermolecular interactions; Physics; Structural analysis; X-ray diffraction; Charge transfer compounds; X-ray diffraction; Intermolecular interactions; DFT calculation; Hirshfeld surface analysis; Structural analysis
• ISSN: 0022-2860; 1872-8014; 0022-2860
• DOI: 10.1016/j.molstruc.2019.04.084

The present work focuses on the crystal structure analysis, vibrational spectroscopy investigation and DFT calculation. Two new charge transfer compounds; bis (creatininium) fumarate fumaric acid (I) and creatininium 3,5-dicarboxybenzoate monohydrate (II), have been synthesized, their Raman and IR modes of vibrations have been assigned and their crystal structures have been studied by means of single crystal X-ray diffraction. Complementary Hirshfeld surface analysis were carried out to investigate and quantify the contributions of the different intermolecular interactions within the crystal. This analysis revels that the main contributions in both compounds are provided by the O⋯H and H⋯H interactions that represent ∼70 (for I) and ∼75% (for II) of the total contributions to the Hirshfeld surface. The results of the theoretically predicted structural parameters and vibrational frequencies are in good agreements with the experimental investigations. These results show that both compounds exhibit similar features, however the energy gap between EHOMO and ELUMO obtained from the molecular orbital analysis indicates that compound (I) is characterized by a molecular structural more favourable for charge transfer. [Display omitted] •Bis (creatininium) fumaratefumaric acid (I) and creatininium 3,5-dicarboxybenzoate monohydrate (II), have been synthesized.•Bothcompounds crystallize in a centrosymmetric space groupe.•The crystal structure of (I) and (II) was stabilized by strong NH⋯O and OH···Ohydrogen bonds.•Experimentally observed frequencies are in good agreement with the calculated values.