The electronic effects of ligands on metal-coordination geometry: a key role in the visual discrimination of dimethylaminopyridine and its application towards chemo-switch

Maji

et al. 2021

Applied Organom Chemis

Bis(imino)pyridine (NNN)‐type ligand [(PyPhime‐Cina) = 2,6‐bis((E)‐1‐phenyl‐2‐((E)‐3‐phenylallylidene)hydrazinyl)pyridine] was synthesized, and a new family of metal complexes [Mn(PyPhime‐Cina)Cl2] (1), [Fe(PyPhime‐Cina)Cl2] (2), [Co(PyPhime‐Cina)Cl2] (3), [Ni(PyPhime‐Cina)Cl2] (4), and [Cu(PyPhime‐Cina)Cl2] (5), derived from the ligand, have been synthesized and characterized. Molecular structures of the ligand and complexes 1‐5 were determined using X‐ray crystallography. Electronic properties and frontier molecular orbitals of the complexes were investigated by DFT and TD‐DFT calculations. DNA interaction studies were evaluated by UV‐visible absorption, fluorescence and circular dichroism spectral studies which indicated noncovalent binding of complexes with CT‐DNA. Hirshfeld surface analysis of all the complexes was studied to know the weak interaction present in the molecules.

Section: Resultsmentioning

confidence: 98%

A new family of complexes derived from bis(imino)pyridine‐type ligands: Crystal structures and bio‐molecular interaction studies

Maji

et al. 2021

Applied Organom Chemis

“…A series of reported results of the coordination between Cu 2 + ions and carboxylate-rich substances through the X-ray crystallographica nalysis of MOFs are valuable for our study. [59][60][61][62][63] The most common coordination number of Cu 2 + is 5w ith the www.chemeurj.org square-pyramidal geometry,a sp rovenb yT ue tal., [63][64][65][66] and H 2 Om olecules usually bind to the metal center to complete the multiple coronation geometry. [59,62,63] The proposed schematic is shown in Scheme 2.…”

Section: Explanation Of the Mechanismmentioning

confidence: 99%

Hydrogels Triggered by Metal Ions as Precursors of Network CuS for DNA Detection

Wang

Song

Hao

et al. 2015

Chemistry A European J

The gelation behavior of lithocholate (LC(-) ) with different metal ions in water was investigated. The microstructures of hydrogels were determined to be three-dimensional (3D) networks of fibrous aggregates. The formation of fibrils was speculated to be mainly driven by the coordination between carboxylate of LC(-) and metal ions, accompanied by the assistance of noncovalent interactions such as electrostatic and hydrophobic interactions. The hydrogels, which can maintain the mechanical strength at higher temperature, exhibit thermal stability. Their gelation capability was enhanced with the increase in acidity. The hydrogels of LC(-) and Cu(2+) mixtures served as the precursors for producing network nanostructures of CuS nanoparticles. These new CuS networks exhibit high fluorescence quenching ability and can act as an effective fluorescent sensing platform for ssDNA detection.

“…As an important family of molecules that have been formerly employed in the study of gel formation successfully, terpyridine compounds include terpyridine, which is functionalized at the central ring with an aromatic group, electron-withdrawing group, donating group, or heterocyclic substituents, such as furan, thiophene, oxazole, etc. − Here, a complete survey of the gelation properties of a series of terpyridine and dipyrazine–pyridine ligands, CuCl 2 [Terpy- n CN] and CuCl 2 [Dipyz-py- n CN], where [Terpy- n CN] is 4′-( n -cyanophenyl)-2,2′,6′,2″-terpyridine and [Dipyz-py- n CN] is 4-( n -cyanophenyl)-2,6-di-pyrazin-2-yl-pyridine, Scheme , in the presence of metal salts is reported. In general, establishing H-bonding interactions, π–π stacking contacts, and metal coordination by using simple and easily available ligands, like those mentioned above, is feasible.…”

Section: Introductionmentioning

confidence: 99%

Is Gelation Behavior Predictable through a Crystal Engineering Approach? A Case Study in Four Similar Coordination Compounds

Khavasi

Esmaeili

2019

Langmuir

In this paper, a detailed study on the gelation properties of a series of terpyridine and dipyrazine−pyridine ligands in the presence of metal salts is reported. To reveal the driving forces for the self-assembly of the metallogelators, their crystal structure is scrutinized. Inspired by the gelation of CuCl 2 [Terpy-nCN], where "Terpy-nCN" is 4′-(n-cyanophenyl)-2,2′,6′,2″terpyridine, to look into the aggregation behavior of the related analogues, synthesis of CuCl 2 [Dipyz-py-nCN] derivatives, where "Dipyz-py-nCN" is 4-(n-cyanophenyl)-2,6-di-pyrazin-2yl-pyridine, with the same cyano groups is performed. We then find that the Dipyz-py counterpart forms crystals when the molecules are stacked in an alternating way, instead of the unidirectional one required for gel formation. A crystal engineering approach is applied to determine the interactions that are favorable for fabricating a fiber network that is likely to be present in both crystalline and gel states and to find the interaction that disturbs this delicate balance between gelation and crystallization in coordination compounds; then, we conclude that the subtle balance between the molecular shape and intermolecular interactions is the origin of the gelation and crystallization of the current molecular system. This enables us to find the mutual connection among the structure of molecules, assembly behavior, and intermolecular interactions. With our experiments, a deep understanding of the balance among solution, gelation, and crystallization with subtle molecular diversions is provided.