Spectra calculations are an important branch of theoretical modeling, and due to the significant improvements of high-level computational methods, the calculated spectra can be used directly and sometimes help to correct the errors of experimental observations. On the other hand, theoretical computations assist the experimental assignments. The authors discuss three spectral calculations (UV-Vis, IR and NMR) that are the most widely used. UV-Visible spectrum can be carried out employing time-dependent density functional theory (TDDFT) with B3LYP/631G(d,p) and CAM-B3LYP functional method to illustrate the characteristics of vertical electronic excitations. The vibrational spectra can be generated from a list of frequencies and intensities using a Gaussian broadening function method. NMR chemical shifts can be calculated by density functional theory individual gauge for localized orbitals (DFTIGLO) method and by gauge including atomic orbitals (GIAO) approach.
Part of the book: Density Functional Calculations
In this chapter, we have discussed the characteristics and bioapplicabilities of different ferrocene derivatives, for example, amides, amines, sulfonamide, and polymers, focusing mainly on urea and thiourea derivatives due to their autonomous and widespread spectroscopic action and bioactivities. Supramolecular chemistry of ferrocenyl ureas and thioureas is described owing to exploring their mode of interactions within and among the molecules and the role of these supramolecular structures in enhancing the DNA intercalation. DNA interaction studies of these ferrocenyl-based ureas and thioureas are explored with approaches like electrochemical study, viscosity measurements, molecular docking, electronic spectroscopy, dynamic light scattering (DLS), and radical scavenging activity. Attachment of ferrocene moiety to ureas an thiouereas closer to DNA is very promising strategy which most possibly boosts the probability of DNA damage and cell apoptosis which is responsible for enormous biological activities.
Part of the book: Photophysics, Photochemical and Substitution Reactions