Crystallographic and first‐principles density functional theory study on the structure, noncovalent interactions, and chemical reactivity of 1,5‐benzodiazepin‐2‐ones derivatives

Abstract

The present work arose out of a desire to fundamentally understand the molecular geometry, weak interactions, electron density delocalization, and chemical reactivity features of 1,5‐benzodiazepines‐containing family. Herein, a complete X‐ray crystallographic study, supported by trustworthy sets of computational approaches, has been reported for two organic crystals. Quantifying intramolecular and intermolecular interactions by Hirshfeld‐Becke surfaces analysis conjointly with noncovalent interaction‐reduced density gradient topological study revealed that supramolecular assemblies are stabilized by N‐H …O (inter) and O‐H …N (intra) hydrogen bonds, Cg …Cg (π …π) and C‐H(O) …π intercontacts, as well as Van der Waals interactions and steric effects. The long‐range‐corrected functional wB97XD, which uses Grimme's D2 dispersion model, seems to be just right for our systems. The quantum theory of atoms in molecules analysis confirms that both significant O1‐H1…N1 and N2‐H2A…O2 H‐bonds are weak and electrostatic in nature. Furthermore, global reactivity indices computed via the conceptual density functional theory framework allows these molecules to be classified as moderate electrophiles and marginal nucleophiles. The active sites favorable for nucleophilic/electrophilic attacks were also predicted based on local Parr functions. Finally, a comparative evaluation on the aromaticity character and π‐π stacking ability has been done for different (pseudo) rings.

A newly synthesized nitrogen‐rich derivative of bicyclic quinoxaline—Structural and conceptual DFT reactivity study

“…In the same way, as we have carried out in our recent work, the chemical reactivity behaviours of title compound have been investigated via CDFT. The shape and energies of HOMO and LUMO orbitals of neutral molecule were predicted and displayed in Figure .…”

“…Since this research is part of an ongoing project, the computational details are almost the same as our previous work and will be briefly represented here. All DFT calculations were accomplished at wB97X‐D/cc‐pVDZ level using Gaussian 09, Rev D.01 software package and GaussView 6.0 program .…”

“…The substituent on N1 is nearly orthogonal to the dihydroquinoxaline unit as indicated by the C6/N1/C10/ C11 torsion angle of −83.06 (16) . The dihedral angle between the C1/C6/N1/C7/C8/N2 and the C11/C12/N3/ N4/N5 rings is 70.88 (8) .…”

“…[1][2][3][4][5][6] Particularly, nitrogen-containing heterocyclic systems are known to exhibit excellent pharmacological activities. [7,8] Thus, quinoxaline and its derivatives have been extensively studied. Notably, these N-heterocycles play an interesting role as basic skeleton for the synthesis of many other pharmacologically and biologically active agents.…”

“…In the past few decades, design and characterisations of heterocyclic organic compounds have received considerable attention because of their pivotal role and wide application in different areas of life science . Particularly, nitrogen‐containing heterocyclic systems are known to exhibit excellent pharmacological activities . Thus, quinoxaline and its derivatives have been extensively studied.…”