A Chiral Bis‐Naphthylated Tetrandrine Dibromide: Synthesis, Self‐Assembly into an Organic Framework Based On Nanosized Spherical Cages, and Inclusion Studies

Abstract

Crystalline framework materials have gained interest because of their many potential applications. A novel chiral tetrandrine salt (DNT) has been synthesized and characterized by conventional analytical techniques and single‐crystal X‐ray diffraction analysis, and its self‐assembly behavior studied. In the solid state, 48 molecules of the compound self‐assemble into an organic framework based on nanospherical aggregates formed exclusively through weak noncovalent interactions. Additionally, it was demonstrated by UV‐vis spectroscopy and TGA that assembled DNT can include the Nile Red dye, giving a fluorescent material. To the best of our knowledge, these spherical assemblies are the largest among the purely synthetic organic self‐assembled molecular crystals reported to date.

DNA-Binding Properties of Bis-N-substituted Tetrandrine Derivatives

“…The bis- N -substituted derivatives BBT, BNaphT, and BAqT were prepared in moderate to good yields as reported previously in the literature. 22 , 24 , 27 In analogous manner, the novel tetrandrine salts BInT and BPyrT were synthesized by quaternization of the tertiary amine groups of the alkaloid with 3-(2-bromoethyl)indole and 1-(bromomethyl)pyrene, respectively ( Figure 1 ).…”

“…In the case of BNaphT, the experiments were not reproducible, which might be a consequence of the self-assembly characteristics of this compound as described previously. 27 …”

“…In the case of BNaphT, the experiments were not reproducible, which might be a consequence of the self-assembly characteristics of this compound as described previously. 27 To gain better insight into the supramolecular interactions involved in the binding of the tetrandrine derivatives to dsDNA, the thermodynamic parameters ΔH and ΔS were calculated from the binding constants determined at different temperatures for the complexes with DNA-1, using the van't Hoff equation (Table S1 and Figures S8−S11, Supporting Information). BPyrT and BInT gave favorable enthalpic and entropic contributions to the Gibbs free energy (Table 1).…”

Molecular Dynamics Studies of Aromatic Guests in Three Isostructural Inclusion Compounds with Molecular Boron–Nitrogen Hosts

“…Initially, mainly hydrogen-bond forming reagents such as hydroquinone, urea, and other organic compounds were reported; 10−12 however, in past few years, several compounds exhibiting other noncovalent interactions were introduced, 13 including molecular containers linked only through van der Waals contacts. 7,14 Organoboranes and organoboronic esters are versatile Lewis acids that readily coordinate to nitrogen-containing Lewis bases, 15 which can be used to prepare inclusion complexes. The generally good stability at ambient conditions (air/water) and interesting physical and chemical properties has stimulated intense activity in the investigation of molecular boron← nitrogen (B←N) compounds.…”

“…The development of lattice inclusion compounds (clathrates) based on molecular organic compounds and materials is of considerable interest due to numerous applications in the fields of selective molecular recognition, − separation, , resolution of racemates, storage, fluorescent materials, , etc. Initially, mainly hydrogen-bond forming reagents such as hydroquinone, urea, and other organic compounds were reported; − however, in past few years, several compounds exhibiting other noncovalent interactions were introduced, including molecular containers linked only through van der Waals contacts. , …”