• Debajyoti Ghoshal

Articles written in Journal of Chemical Sciences

• Fabrication of supramolecular frameworks by tuning the binding site of a tripodal ligand with $d^{10}$ metal ions: Interplay of covalent and non-covalent interactions in solid-state structure

Two new coordination polymers of Zn(II) and Cd(II) have been synthesized using 2,4,6-tri(4-pyridyl)-1,3,5-triazine (tpt), where it acts as a bi-bridging ligand. The compounds are characterized by IR spectroscopy, elemental analysis and single crystal X-ray diffraction studies. Compound [Zn(tpt)(NO3)2(H2O)2]$_n$ (1) and [Cd(tpt)(NO3)2(H2O)2]$_n$ (2) are isomorphous and show 1D coordination structure with almost octahedral metal center, which is extended to supramolecular 3D structure by cooperative weak interactions, like H-bonding, $\pi-\pi$ and C-H…O interactions. Both the compounds reveal interplay of covalent and non-covalent interactions for fabricating supramolecular solid-state architecture.

• Synthesis, crystal structure and photo luminescent property of a 3D metal-organic hybrid of Cd(II) constructed by two different bridging carboxylate

A solvothermal reaction of cadmium (II) nitrate with succinic acid and isonicotinic acid creates a novel 3D metal-organic framework, [Cd3(isonicotinate)2(suc)2]$_n$(1). Single crystal X-ray structure determination reveals that complex 1 posses two crystallographically independent Cd(II) centres. The succinate anion acts here as a heptadented ligand and binds five Cd(II) centre simultaneously. The heptacoordinated Cd(II) centres are oxo-bridged by succinate moiety and the hexacoordinated metal centres are terminally connected through four different succinate moiety to make the overall 2D sheet arrangement. In unit cell, the ratio of hexadented Cd(II) and heptadented Cd(II) is 1:2. The new compound was also characterized by luminescence spectra and compared with the luminescence spectra of the pure isonicotinic acid.

• Two 3D supramolecular frameworks assembled from the dinuclear building block: A crystallographic evidence of carboxylate(O)$\ldots \pi$ interaction

Two new complexes of Mn(II) and Zn(II) have been synthesized using a mixed ligand system and characterized by IR spectroscopy, elemental analysis, single crystal x-ray diffraction and variable temperature magnetic study for one of the compounds. Dimeric coordination structures of [Mn2(2,4-pyrdc)2(bpe)(H2O)6]·2H2O (1) and [Zn2(2,4-pyrdc)2(azpy)(H2O)6]·2H2O (2) [2,4-pyrdc = 2,4-pyridinedicarboxylate; bpe = 1,2-bis(4-pyridyl)ethane; azpy = 4, 4' azopyridine] are constructed by the bridging of bpe and azpy, respectively and both are extended to a 3D supramolecular structure by non-covalent interactions. In both the cases, unprecedented carboxylate(O)$\ldots \pi$ interactions played a crucial role in the organization of the 3D supramolecular assembly. The carboxylate(O)$\ldots \pi$ interactions are controlled by the C-H$\ldots \pi$ interactions which were accomplished by the proper modulation of the organic linkers. The formation of these supramolecular frameworks revealed that control of weak interactions can be achieved by the interplay of both energetically strong (covalent) and weak forces (non-covalent).

• Syntheses and characterization of three diphenyl phosphate based Cu(II) complexes and the effect of non-covalent interactions on their supramolecular framework

Assembly of diphenylphosphate (dpp) with Cu(II) salts in combination with the different Ndonor linkers, e.g., pentamethyldiethylenetriamine (pmdeta), bis-(3-aminopropyl)amine (bapa) and 4-Picolene (4-pic), yielded three new metal-organic coordination complexes, namely {[Cu(dpp)(pmdeta)]·ClO₄.H₂O}₂ (1), {[{[Cu(dpp)(bapa)H₂O]·ClO₄} (2) and [Cu(dpp)2(4-pic)₂]₂ (3) by stirring the constituent reactants at room temperature. Complexes 1–3 were characterized by single crystal X-ray diffraction analysis and were further characterized by elemental analysis, infrared spectroscopy (IR) and powder X-ray diffraction (PXRD) studies. Compound 1 exhibits a dimeric Cu(II) complex which forms a 1D supramolecular chain along the crystallographic c-axis by means of intermolecular π .. .π interactions. Compounds 2 and 3 form a monomeric and dimeric complex of Cu(II) respectively, which are further extended into a supramolecular 2D structure viaC-H..π interactions for 2 and a 3D structure for 3 with the help of both intermolecular C-H..π and π . . . π interactions for 3. In addition, the solid state UV-Vis spectra of compounds 1-3 and free dpp ligand have beeninvestigated at room temperature.

• Journal of Chemical Sciences

Volume 134, 2022
All articles
Continuous Article Publishing mode

• Editorial Note on Continuous Article Publication

Posted on July 25, 2019

Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.