Control of Molecular Conformation and Crystal Packing of Biphenyl Derivatives

Abstract

This Review presents a discussion of the conformation of biphenyl derivatives in different chemical environments. The interplay between aromatic stabilization and steric repulsion, normally considered to explain the conformation of the molecule, is contrasted with the interpretation provided by models not based on molecular orbitals. The electronic control of conformation by means of appropriate hydrogen substitution is discussed by examples taken from chemistry and molecular electronics. Supramolecular synthons involving biphenyl are critically analyzed in terms of the molecular conformation, crystal packing and intermolecular forces. Some directions for future research on the control of the conformation of biphenyls are also presented.

Facile Synthesis of Rigid Binuclear Manganese Complexes for Magnetic Resonance Angiography and SLC39A14-Mediated Hepatic Imaging

“…between the π−π delocalization between the aromatic rings and the steric repulsion between hydrogen atoms on the benzene ring near the σ bond. 42 Based on the fact that the larger molecular size of Mn 2 -TPA-PhDTA 2 has a slightly lower relaxation efficiency, the structure of Mn 2 -PhDTA 2 with better rigidity may be the most reasonable explanation. In addition, compared to Mn 2 -TPA-PhDTA 2 , Mn 2 -PhDTA 2 exhibited more advantageous mass efficiency (ratio MW/r 1 = molecular weight/relaxivity, 132 vs 163).…”

“…The advantage of Mn 2 -PhDTA 2 over Mn 2 -TPA-PhDTA 2 is that the biphenyl structure may have better rigidity than the amide-coupled structure, although the hyperconjugation of the amide functional group also increased the rigidity of Mn 2 -TPA-PhDTA 2 . In fact, the σ bond between the two benzene rings in the biphenyl structure does not rotate completely randomly but rather has an advantageous torsion angle, which is thought to be the result of an equilibrium between the π–π delocalization between the aromatic rings and the steric repulsion between hydrogen atoms on the benzene ring near the σ bond . Based on the fact that the larger molecular size of Mn 2 -TPA-PhDTA 2 has a slightly lower relaxation efficiency, the structure of Mn 2 -PhDTA 2 with better rigidity may be the most reasonable explanation.…”

Superlong Metal–Organic Framework Micro-/Nanofibers for Selective Vitamin Absorption

“…The vibrational state is also observed in the IR spectrum of Co-MOF-74-II-NFs (Figure S9). Thus, dobpdc 4– is considered to be a more flexible molecule compared to dobdc 4– , and it may adapt to a variety of spatial configurations . The use of a flexible linker can introduce disorder or variability in the arrangement of the framework, resulting in an amorphous structure.…”

“…Thus, dobpdc 4− is considered to be a more flexible molecule compared to dobdc 4− , and it may adapt to a variety of spatial configurations. 47 The use of a flexible linker can introduce disorder or variability in the arrangement of the framework, resulting in an amorphous structure. However, the existence of nanocrystals in Co-MOF-74-II-NFs is supported by the XRD data.…”

Self-assembly induced ferromagnetic interaction in magnetic polymers with terphenyl linkers

“…29 The π–π stacking interaction of the para -terphenyl groups is higher than that of the biphenyl group, probably due to the good co-planarity of para -terphenyl groups. 40–42 As a result, the PTMTBDI[FeCl 4 ] molecules pack compactly and shorten the nearest Fe( iii )–Fe( iii ) distance. Although the lattice structure is not as perfect as inorganic crystals or metal alloys, the magnetic polymer with ordered lattice structures within the atomic scale is very exciting for the possibility of manipulating atoms in a designed way.…”