Critical assessment of interactions between ct-DNA and choline-based magnetic ionic liquids: evidences of compaction.

Ionic liquids (ILs) have become an alternative green solvent for storage and for stability of DNA. However, an in-depth understanding of binding and molecular interactions between ILs and DNA is needed. In this respect, magnetic ILs (MILs) are promising due to their tunable physicochemical properties.

Critical assessment of selenourea as an efficient small molecule fluorescence quenching probe to monitor protein dynamics.

Organoselenium compounds have recently been the experimentalists' delight due to their broad applications in organic synthesis, medicinal chemistry, and materials science. Selenium atom replacement of the carbonyl oxygen of the urea moiety dramatically reduces the HOMO-LUMO gap and oxidation potential, which completely changes the physicochemical properties of selenocarbonyl compounds. To our surprise, the photophysics and utility of a simple molecule such as selenourea (SeU) have not been explored in detail, which persuaded us to investigate its role in excited state processes.

Intermolecular noncovalent interactions with carbon in solution.

One of the most familiar carbon-centered noncovalent interactions (NCIs) involving an antibonding π*-orbital situated at the Bürgi-Dunitz angle from the electron donor, mostly lone pairs of electrons, is known as n → π* interactions, and if it involves a σ* orbital in a linear fashion, then it is known as the carbon bond. These NCIs can be intra- or inter-molecular and are usually weak in strength but have a paramount effect on the structure and function of small-molecular crystals and proteins. Surprisingly, the experimental evidence of such interactions in the solution phase is scarce.

Quantification of the electric field inside protein active sites and fullerenes.

While electrostatic interactions are exceedingly accountable for biological functions, no simple method exists to directly estimate or measure the electrostatic field in protein active sites. The electrostatic field inside the protein is generally inferred from the shift in the vibrational stretching frequencies of nitrile and thionitrile probes at the active sites through several painstaking and time-consuming experiments like vibrational Stark effect spectroscopy (VSS). Here we present a simple, fast, and reliable methodology, which can efficiently predict the vibrational Stark tuning rates (VSRs) of a large variety of probes within 10% error of the reported experimental data.

Non-covalent interactions with inverted carbon: a carbo-hydrogen bond or a new type of hydrogen bond?

In contrast to the conventional and non-conventional non-covalent interactions (NCIs) such as hydrogen bond and carbon bond, a bidirectional NCI without π- and/or lone pair(s) of electrons has never been reckoned until the present report, which confirms that this type of NCI can be possible with the involvement of mostly σ-electrons. This newly discovered NCI can be coined as carbo-hydrogen bond (CH-bond) based on its resemblances with both carbon bond (C-bond) and hydrogen bond (H-bond) or Ci:::H interaction. A detailed crystal structure analysis of 5-cyano-1,3-dehydroadamantane, which contains inverted carbon atoms (Ci) and Ci-Ci σ-bond, gave us the opportunity to unveil the very first existence of the Ci:::H interaction.