15 research outputs found

    Investigating color additive molecules for pharmaceutical and cosmetic applications: A comparison of theoretical and experimental UV-visible absorbance spectra in tunable solvents

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    Color additive molecules have widespread applications ranging from ingestible foods and pharmaceutics to non-ingestible cosmetics and other naturally or synthetically developed consumer products available worldwide. Certification for approved use of color additives varies globally; therefore, a feasible method to analyze existing color additives or to design novel color additive molecules with enhanced or otherwise desired physicochemical properties (such as hue) is in high demand for universal adoption. The studies herein provide sufficient proof that density functional theory and time-dependent density functional theory serve as effective predictive modeling techniques for generating theoretical maximum absorbance spectral peak responsivity for a single color additive molecule structure in the virtual workspace, as well as for multiple (heterodimeric and heterotrimeric) structures represented simultaneously. Furthermore, DFT and TD-DFT can be used to analyze changes in hue attributed to structural anomalies in molecules due to tautomerism, vibronic effects, intra- or intermolecular interactions, implicit or explicit solvation effects, or charge transfer effects on the structure represented in a given solvent or in vapor phase. Advancements in computational processing make incorporation of these and similar advanced ab initio quantum chemical methods more tangible for the modern pharmaceutical or cosmetic formulator to use in perfecting batch hue

    Intramolecular Hydrogen Bonding 2021

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    This book describes the results of both theoretical and experimental research on many topical issues in intramolecular hydrogen bonding. Its great advantage is that the presented research results have been obtained using many different techniques. Therefore, it is an excellent review of these methods, while showing their applicability to the current scientific issues regarding intramolecular hydrogen bonds. The experimental techniques used include X-ray diffraction, infrared and Raman spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), nuclear quadrupole resonance spectroscopy (NQR), incoherent inelastic neutron scattering (IINS), and differential scanning calorimetry (DSC). The solvatochromic and luminescent studies are also described. On the other hand, theoretical research is based on ab initio calculations and the Car–Parrinello Molecular Dynamics (CPMD). In the latter case, a description of nuclear quantum effects (NQE) is also possible. This book also demonstrates the use of theoretical methods such as Quantum Theory of Atoms in Molecules (QTAIM), Interacting Quantum Atoms (IQA), Natural Bond Orbital (NBO), Non-Covalent Interactions (NCI) index, Molecular Tailoring Approach (MTA), and many others

    43rd Rocky Mountain Conference on Analytical Chemistry

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    Final program, abstracts, and information about the 43rd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 29 - August 2, 2001

    The Halogen Bond

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    The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design

    DFT explorations of quadrupole coupling constants for planar 5-fluorouracil pairs

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    Atomic scale properties of quadrupole coupling constants (CQ) have been evaluated for singular and paired 5-fluorouracil (FU) models. Structural possibilities and properties for various types of hydrogen bonded (HB) homo pairs of FU have been investigated based on density functional theory (DFT) calculations. The models have been optimized to obtain the minimum energy level structures and only the planar molecular pairs have been considered. Various types of HB interactions have also managed the molecular shapes for the FU pairs. Different types of energies and also electron transferring properties have been investigated by the evaluated optimized properties. The atomic scale results indicated different strengths of HB interactions for FU pairs according to the changes of CQ properties for atoms in the singular and paired systems depending on the strength of interactions. © 2016 Elsevier B.V

    45th Rocky Mountain Conference on Analytical Chemistry

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    Final program, abstracts, and information about the 45th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 27-31, 2003

    36th Rocky Mountain Conference on Analytical Chemistry

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    Program, abstracts, and information about the 36th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 31 - August 5, 1994

    41st Rocky Mountain Conference on Analytical Chemistry

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    Final program, abstracts, and information about the 41st annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 1-5, 1999
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