Structure and barrier of internal rotation of biphenyl derivatives in the gaseous state: Part 1. The molecular structure and normal coordinate analysis of normal biphenyl and pedeuterated biphenyl

In this paper, we report on a high-throughput (gram quantities) solvothermal method for the synthesis of copper terephthalate metal–organic frameworks in dmf. While the structure of MOF-2 and some of the associated polymorphs are well known, we know of no equivalent structural studies for the isostructural copper terephthalate (Cu–tpa). The material we have made crystallizes in the C2/m space group. Cu–tpa also exhibits reversible solvent-exchange properties. These properties make this material useful for potential applications in gas storage and catalysis applications. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Synthesis and Structure Characterization of Copper Terephthalate Metal–Organic Frameworks

This photophysical study addresses the general question of how electron transfer in bichromophoric molecules influences the conformational relaxation, which can be toward either more or less π-conjugation. The effects of photoinduced intramolecular charge transfer on the electronic and molecular properties of a series of differently twisted 4-N,N-dimethylamino-4‘-cyanobiphenyls are investigated by steady-state and time-resolved fluorescence. The dipole moments, radiative rates, and torsional relaxations in the excited state are analyzed by comparison with the absorption spectra and interannular twist angle (φ)-dependent CNDO/S calculations. Independent of the twist angle φ and solvent polarity, the first excited singlet state of these donor−acceptor (D−A) biphenyls (I−III) is an emissive intramolecular 1CT state of the 1La-type transferring charge from the dimethylaminobenzene (D) to the cyanobenzene (A) subunit. Similar to the planar restricted D−A fluorene I, the flexible D−A biphenyl II shows only a we...

Photoinduced Intramolecular Charge Transfer in a Series of Differently Twisted Donor−Acceptor Biphenyls As Revealed by Fluorescence

The fundamental physical and chemical phenomena that can occur at interfaces between conjugated organic molecules and metal surfaces are discussed. The adsorption strength of molecular monolayers on metals covers a wide range from the weak physisorption regime to strong chemisorption, involving charge transfer and/or covalent bond formation. In many cases, molecular conformation changes can be observed, which directly impact the interface electronic structure and charge injection across the organic/metal contact. The energy level positions of organic multilayers are essentially determined by the monolayer/metal interaction, and 'flat-band' conditions prevail for thicker layers of pure organic molecules. Consequently, thermodynamic equilibrium across organic semiconductor films may not always be established.

https://iopscience.iop.org/article/10.1088/0953-8984/20/18/184008/pdf

Energy levels at interfaces between metals and conjugated organic molecules

Urinary tract infection (UTI) by uropathogenic Escherichia coli (UPEC) is one of the most common infections, particularly affecting women. The interaction of FimH, a lectin located at the tip of bacterial pili, with high mannose structures is critical for the ability of UPEC to colonize and invade the bladder epithelium. We describe the synthesis and the in vitro/in vivo evaluation of α-D-mannosides with the ability to block the bacteria/host cell interaction. According to the pharmacokinetic properties, a prodrug approach for their evaluation in the UTI mouse model was explored. As a result, an orally available, low molecular weight FimH antagonist was identified with the potential to reduce the colony forming units (CFU) in the urine by 2 orders of magnitude and in the bladder by 4 orders of magnitude. With FimH antagonist, the great potential for the effective treatment of urinary tract infections with a new class of orally available antiinfectives could be demonstrated.

FimH antagonists for the oral treatment of urinary tract infections: from design and synthesis to in vitro and in vivo evaluation.

The dihedral angle between the rings of biphenyl is determined to be 32 ± 2° in the molten and solution states. Observed vibrational frequency shifts on going from the planar configuration held in the crystal to the non-planar solution state are compared with computed frequency shifts. To improve the accuracy in the computed frequencies the force constants were refined. The values of the force constants associated with the inter-ring bond are discussed.

D. Steele

Papers

Dihedral angle of biphenyl in solution and the molecular force field

The vibrational force field of halogenated aromatic molecules In-plane vibrations of benzene and fluorobenzenes

The vibrational spectra of amides—Dimethyl formamide

The vibrational spectra of amides. II: The force field and isotopic shifts of N,N-dimethyl formamide

The low frequency absorption spectra and assignments of fluoro benzenes