Submolecular partitioning of morphine hydrate based on its experimental charge density at 25 K

Abstract

The electron density distribution of morphine hydrate has been determined from high-resolution single-crystal X-ray diffraction measurements at 25 K. A topological analysis was applied and, in order to analyze the submolecular transferability based on an experimental electron density, a partitioning of the molecule into atomic regions was carried out, making use of Bader's zero-flux surfaces to yield atomic volumes and charges. The properties obtained were compared with the theoretical calculations of smaller fragment molecules, from which the complete morphine molecule can be reconstructed, and with theoretical studies of another opiate, Oripavine PEO, reported in the literature.

Co-crystal/salt crystal structure disorder of trichloroacetic acid–N-methylurea complex with double system of homo- and heteronuclear O–H···O/N–H···O hydrogen bonds: X-ray investigation, ab initio and DFT studies

“…C1-C2 and N4-C5 as formal single bonds have small values of ellipticity comparable to known literature [70][71][72]. N-C3 in nmur moiety may be considered as double ones with e BCP about 0.2.…”

An Introduction to the Quantum Theory of Atoms in Molecules

“…Atomic properties have also been used empirically to predict several experimental properties including for example, the pK a of weak acids from the atomic energy of the acidic hydrogen [96], a wide array of biological and physicochemical properties of the amino acids, including the genetic code itself, and the effects of mutation on protein stability [60], protein retention times [97], HPLC column capacity factors of high-energy materials [98], NMR spin-spin coupling constants from the electron delocalization indices [99,100], simultaneous consistent prediction of five bulk properties of liquid HF in MD simulation [101], classification of atom types in proteins with future potential applications in force-field design [60,[102][103][104], reconstructing large molecules from transferable fragments or atoms in molecules [60,[105][106][107][108][109][110][111][112][113][114][115][116][117][118][119] (see also Chapters 11 and 12), atomic partitioning of the molecular electrostatic potential [120][121][122], prediction of hydrogenbond donor capacity [123] and basicity [124], and to provide an atomic basis for curvature-induced polarization in carbon nanotubes and nanoshells [125].…”

Special issue: Philosophical aspects and implications of the quantum theory of atoms in molecules (QTAIM)

“…The transferability and additivity of the atoms defined by QTAIM have been used extensively to reconstruct the properties of large molecules from smaller fragments [See for example: (Chang and Bader 1992;Sukumar and Breneman 2007;Scheins et al 2005)]. If such reconstruction of the properties of large molecules from composing atoms and groups stored in a database, with chemical accuracy, does not constitute prediction, how would that be characterized?…”