Hole interactions are known by different names depending on the key atom of the bond (halogen bond, chalcogen bond, hydrogen bond, etc.), and the geometry of the interaction (σ if...

In this article, we have examined the effect of substitution on the formation of neutral XHSe···O/N (X = -H, -F, -CH3, -CF3, -Cl, -OH, -OCH3, -NH2, -NHCH3, -CN) noncovalent bonds with the oxygen atom from H2O molecule and the nitrogen atom from NH3 being the electron donor atoms, respectively. In addition to this, analysis has also been performed on XMeSe···O/N complexes to study the effect of the role of hydrogen bonding with the hydrogen atoms of the methyl group on Se···O/N interactions. Binding energy calculations were performed to determine the strength of these contacts. The obtained results establish the fact that the presence of a methyl group influences the strength of the observed Se···O/N interactions. Also in some cases, the O-H···Se interaction was observed to be more preferable over the Se···O interaction. The major contribution for stabilization of such Se···O/N interactions is from an interplay among the electrostatics and the exchange energy. To obtain deeper insights and understanding of such Se···O/N contacts, a topological analysis, using the QTAIM approach were also performed. This analysis showed that although the presence of a Me group modifies the Se···O/N interaction, it does not necessitate the formation of hydrogen bonds. To obtain insights into the orbital contributions, a natural bond orbital (NBO) analysis were performed which depicts that the strength of such interactions were derived via charge transfer from the oxygen/nitrogen lone pair to the σ* orbital of the Se-X bond.

The calculations performed on the evaluation of the electrostatic potential provide deeper insights into the nature of lp⋯π interactions.

In this article, we have analyzed the nature and characteristics of PSe noncovalent interactions by studying the effect of substitution on XH2PSeH2, H3PSeHX and XH2PSeHX (X= -H, -F, -CH3, -CF3, -Cl, -OH, -OCH3, -NH2, -NHCH3, and -CN) as our systems of interest at MP2/aug-cc-pVDZ level of theory. Binding energy calculations depict that binding energy increases in the order XH2PSeH2 < H3PSeHX < XH2PSeHX with the nature of the substituent having a direct effect on the strength of the interactions. PSe contacts as short as 2.52 Å were observed and analyzed in our study. The energy values for PSe contacts were found to exist in the range of -1.20 kcal mol(-1) to -7.89 kcal mol(-1). The topological analysis confirms the presence of PSe contacts in all the complexes with characteristics similar to hydrogen bonds. NBO analysis helped in categorizing these interactions into pnicogen and chalcogen bonds, depending on the strength of P(lp) to σ*(Se-X) orbitals or Se(lp) to σ*(P-X) orbitals.

An efficient Cp*CoIII‐catalyzed C8‐dienylation of quinoline‐N‐oxides was achieved by employing allenes bearing leaving groups at the α‐position as the dienylating agents. The reaction proceeds by CoIII‐catalyzed C−H activation of quinoline‐N‐oxides and regioselective migratory insertion of the allene followed by a β‐oxy elimination, leading to overall dienylation. Site‐selective C−H activation was achieved with excellent selectivity under mild reaction conditions, and 30 mol % of a NaF additive was found to be crucial for the efficient dienylation. The methodology features high stereoselectivity, mild reaction conditions, and good functional‐group tolerance. C8‐alkenylation of quinoline‐N‐oxides was achieved in the case of allenes devoid of leaving groups as coupling partners. Furthermore, gram‐scale preparation and preliminary mechanistic experiments were carried out to gain insights into the reaction mechanism.