Molecular structure and quantum descriptors of cefradine by using vibrational spectroscopy (IR and Raman), NBO, AIM, chemical reactivity and molecular docking

Synthesis, crystal structure, and a molecular modeling approach to identify effective antiviral hydrazide derivative against the main protease of SARS-CoV-2

“…According to the aforementioned criteria about hydrogen bonding, the BCP designated as 77 should not indicate that there is an intramolecular hydrogen bond in the title compound. Although the NBO analysis and QTAIM study have already been used as powerful tools to investigate intra- or intermolecular hydrogen bonding of several systems [ 54 , 59 , 60 , 61 , 62 , 63 ], they seemed not to be suitable to describe the intramolecular hydrogen bonds among the title compound in this study.

Figure 10 The (3,-3), (3,-1), and (3,+1) BCPs of the title compound.

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Supramolecular Self-Assembly Process during Gelation and Crystallization of Cefradine

“…In addition, the band was accompanied by a significant red shift with the transformation of solution–gel–crystal. The band near 2700 to 3100 cm –1 was attributed to the stacked amino-carboxyl groups in supramolecular assemblies of cefradine, which means that hydrogen bond NH···O=C is formed. , Therefore, the observed 2900 cm –1 band indicates that, in the gel phase of the cefradine-DMF system, regardless of the existence of crystals, the supramolecular structure drives the packing of solution into fibrillar assemblies in a process mediated by the interactions of amino and carboxyl. Moreover, the increased intensity and red shift of the 2900 cm –1 band suggested that a larger portion of fibers were arranged into well-organized assemblies during crystallization, well after the gelation.…”

“…The cefradine molecules have the ability to form various intermolecular directional interactions, including hydrophobic interactions, hydrogen bonding, and electrostatic interactions, which allows the formation of diverse classes of supramolecular assemblies. − Furthermore, this building block has the potential to form hydrogels, which were proven to be LMWGs in this research. The sol–gel–crystal transition, where monomeric molecules transform into partially ordered fibrillar nanostructures and then transform into the highly ordered crystals, can further assist in monitoring the supramolecular polymerization …”

Topological and Reactivity Descriptor of Carisoprodol from DFT and Molecular Docking Approach

“…The chemical stability of molecules depends upon the energy of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The orbital energy HOMO (E H ) acts as the electron donor and the orbital energy LUMO (E L ) acts as the electron acceptor and their energy gap (E L -E H ) determines the chemical reactivity of the molecule (Chaudhary et al, 2021b;Joshi et al, 2018). The probability of electronic transition activity increases with the increase in the energy gap and vice-versa (Fukui, 1982).…”