Three-dimensional hydrogen bonding network in the structures of (dimethylcyanamide)cobalt(II) complexes

Hydrogen-Bond-Assisted Adsorption of Nitric Oxide on Various Metal-Loaded ZSM-5 Zeolites

Understanding the characteristics of nitric oxide (NO) adsorption on metal-loaded zeolites is a prerequisite for developing efficient catalysts for NO abatement reactions. In this study, we probed the effect of the hydrogen bond that exists between adsorbed NO and Brønsted acid sites (BAS) in various metal-loaded ZSM-5 zeolites (M-ZSM-5, wherein M = Fe, Co, Ni, Cu, Zn, Pd, Ag, and Au) by using density functional theory calculations. The presence of a hydrogen bond has altered the NO adsorption energies significantly; appreciable stabilization via hydrogen bonding is noted for NO complexes of Zn, Fe, and Co, and reasonable stabilization is obtained for Ni and Cu complexes, whereas an anomalous effect of a hydrogen bond is identified in Ag, Pd, and Au species. Moderate weakening of the N-O bond in all NO-adsorbed complexes primarily due to a hydrogen bond has been realized in terms of Mayer bond order and quantum theory of atoms in molecules topological analyses; N-O bond activation follows the order Ag < Pd < Au < Ni < Cu < Co < Fe < Zn. We obtained a good correlation between hydrogen bond distance and molecular electrostatic potential at the O atom (V_O) of NO adsorbed on BAS-free M-ZSM-5; which suggests that V_O can be considered as a key descriptor to infer the strength of a hydrogen bond between the adsorbed NO and M-ZSM-5 with BAS. Finally, the energy decomposition analysis in combination with natural orbitals for chemical valence has provided the qualitative aspects of electron back-donation from the metal to the antibonding molecular orbital of NO; this back-donation is quite impressive in hydrogen-bond-assisted NO adsorption. We expect that the findings of this study will open up the possibility of the design of BAS-containing metal-loaded zeolites for the catalytic mitigation of NO.

Halogen bonding-assisted assembly of bromoantimonate(v) and polybromide-bromoantimonate-based frameworks

Halogen bonding within bromo- and polybromoantimonates(v).

Recent Advances in Cyanamide Chemistry: Synthesis and Applications

The application of alkyl and aryl substituted cyanamides in synthetic chemistry has diversified multi-fold in recent years. In this review, we discuss recent advances (since 2012) in the chemistry of cyanamides and detail their application in cycloaddition chemistry, aminocyanation reactions, as well as electrophilic cyanide-transfer agents and their unique radical and coordination chemistry.

Intermolecular hydrogen bonding H···Cl− in the solid palladium(II)-diaminocarbene complexes

Weak intermolecular non-covalent H···Cl− interactions in the solid chelated palladium(II)-diaminocarbene complex cis-[PdCl(CNXyl){C(NHXyl)=NHC6H2Me2 NH2}]Cl (3; Xyl=2,6-Me2C6H3) were studied by XRD followed by appropriate DFT calculations. The N–H···Cl contacts for both NH groups in the carbene moiety are different (N1–H···Cl2 3.5258(19), N2–H···Cl2 3.0797(17) Å). The DFT calculations and topological analysis of the electron density distribution within the formalism of Bader’s theory (QTAIM method) were performed for a model cluster of the carbene complex 3. The theoretical data confirmed that the strength of intermolecular HB H···Cl− is different for two NH-protons of the carbene fragment. The influence of crystal packing effects on the formation of hydrogen bonds in the cluster of 3 is noticeable.