Cooperativity of anion⋯π and π⋯π interactions regulates the self-assembly of a series of carbene proligands: Towards quantitative analysis of intermolecular interactions with Hirshfeld surface

Visible-light promoted catalyst-free (VLCF) multi-component synthesis of spiro indolo-quinazolinone-pyrrolo[3,4-a]pyrrolizine hybrids: evaluation of in vitro anticancer activity, molecular docking, MD simulation and DFT studies

A new and highly efficient visible-light-promoted catalyst free (VLCF) strategy for neat and clean synthesis of spiro indolo-quinazolinone-pyrrolo[3,4-a]pyrrolizine hybrids (6a-d) has been introduced. We have performed visible-light triggered 1,3-Dipolar cycloaddition reaction of maleimide (5a-d) with azomethine ylide generated in situ derived from tryptanthrin (3) and L-proline (4) to obtain desired products (6a-d) in good to excellent yield. Authentication and characterization of product was done using various spectroscopic techniques such as IR, 1H NMR, 13C NMR, Mass spectrometry and single crystal XRD analysis. To explain the reaction spontaneity, product stability, reactivity as well as possible mode of the interaction a quantum chemical investigation was performed and depicted through DFT studies. The synthesized compound 6a was also evaluated for anti-proliferative activity against a panel of five cancer cell lines (MCF-7, MDA-MB-231, HeLa, PC-3 and Ishikawa) and normal human embryonic kidney (HEK-293) cell line by using MTT assay. Compound 6a showed very good in vitro anti-proliferative activity (IC50  = 6.58-17.98 μM) against four cancer cell lines and no cytotoxicity against normal HEK-293. In order to evaluate the anticancer potential of compounds 6a-d, molecular docking was performed against wild type and mutant EGFR. The results suggest that all the compounds occupied the active site of both enzymes, with a strong binding energy (-10.2 to -11.5 kcal/mol). These results have been confirmed by molecular dynamics simulation by evaluating root mean square deviation (RMSD) and root mean square fluctuation (RMSF), along with principal component analysis (PCA).Communicated by Ramaswamy H. Sarma.

Solid-state luminescence properties, Hirshfeld surface analysis and DFT calculations of mononuclear lanthanide complexes (Ln = EuIII, GdIII, TbIII, DyIII) containing 4'-phenyl-2,2':6',2″-terpyridine

Four mononuclear lanthanide complexes containing 4'-phenyl-2,2':6',2″-terpyridine (ptpy), [Ln(NO₃)₃(ptpy) (H₂O)] (Ln = Eu (1), Gd (2), Tb (3), Dy (4)), were solvothermally synthesized and characterized via elemental analysis, infrared spectroscopy, thermogravimetric analysis, single-crystal X-ray diffraction, and powder X-ray diffraction. Hirshfeld surfaces and the solid-state luminescence properties of the complexes were investigated. The 3-D Hirshfeld surface and 2-D fingerprint plots show that the main interactions are the O H/H O intermolecular interactions in 1-4. Solid-state luminescence investigation reveals that Gd^III complex 2 displays a ligand-centered emission and the Eu^III, Tb^III and Dy^III complexes 1, 3 and 4 show the characteristic lanthanide-centered luminescence upon UV excitations. The Eu^III and Tb^III complexes exhibit red (CIE: 0.6549, 0.3447) and green (CIE: 0.3760, 0.5412) luminescence in the solid state with quantum yields of 16.8% and 0.8% and lifetimes of 0.545 and 0.043 ms, respectively. Density functional theory (DFT) calculations were conducted to unravel the HOMO-LUMO energy gaps of the structures of ptpy and complexes 1 and 3.

Structural characterization and Hirshfeld surface analysis of a CoII complex with imidazo[1,2-a]pyridine

A new mononuclear tetra-hedral CoII complex, di-chlorido-bis-(imidazo[1,2-a]pyridine-κN1)cobalt(II), [CoCl2(C7H6N2)2], has been synthesized using a bioactive imidazo-pyridine ligand. X-ray crystallography reveals that the solid-state structure of the title complex exhibits both C-H⋯Cl and π-π stacking inter-actions in building supra-molecular assemblies. Indeed, the mol-ecules are linked by C-H⋯Cl inter-actions into a two-dimensional framework, with finite zero-dimensional dimeric units as building blocks, whereas π-π stacking plays a crucial role in building a supra-molecular layered network. An exhaustive investigation of the diverse inter-molecular inter-actions via Hirshfeld surface analysis enables contributions to the crystal packing of the title complex to be qu-anti-fied. The fingerprint plots associated with the Hirshfeld surface clearly display each significant inter-action involved in the structure, by qu-anti-fying them in an effective visual manner.

Screening polymorphism in a Ni(ii) metal–organic framework: experimental observations, Hirshfeld surface analyses and DFT studies

A new polymorphic form of diaquaiminodiacetatonickel(ii) is structurally characterized by a detailed analysis of Hirshfeld surface and further analysed by DFT and QTAIM calculations.

On the importance of Pb⋯X (X = O, N, S, Br) tetrel bonding interactions in a series of tetra- and hexa-coordinated Pb(ii) compounds

We study Pb⋯X (X = N, S, Br) tetrel bonding interactions in a series of tetra- and hexa-coordinated Pb(ii) compounds that exhibit hemidirectional coordination.

Synthesis of gold(iii) ← gold(i)–NHC through disproportionation: the role of gold(i)–NHC in the induction of apoptosis in HepG2 cells

The anticancer activities of novel Au(i) and Au(iii)–NHC complexes based on 2-[(6-methylpyridin-2-yl)]imidazo[1,5-a]pyridin-4-ylium hexafluorophosphate have been investigated.

New Ni(ii) 1,2-bis(diphenylphosphino)ethane dithiolates: crystallographic, computational and Hirshfeld surface analyses

Three new Ni(ii) dppe dithiolates have been synthesized and the nature of weak interactions have been addressed using computational and Hirshfeld surface analyses.

Syntheses, crystal structures and density functional theory investigations of copper(ii) complexes bearing tridentate Schiff base ligands derived from 8-aminoquinoline

Three copper(ii) Schiff base complexes have been synthesized and characterized. Supramolecular assemblies in the solid state are analyzed by DFT calculations.

Using halogen⋯halogen interactions or C/N–H⋯Cl hydrogen bonding to direct crystal packing in tetrachlorophthalic acid with N-heterocyclic compounds

Hydrogen bonding patterns and halogen⋯halogen interactions, C/N–H⋯Cl hydrogen bonding in a series of multi-component molecular structures constructed by tetrachlorophthalic acid with N-heterocycles were discussed.