S. Thinagar

Bio: S. Thinagar is an academic researcher from University of Madras. The author has contributed to research in topics: Ring (chemistry) & Moiety. The author has an hindex of 1, co-authored 6 publications receiving 7 citations.

3,3'-[o-Phenylenebis(methyleneoxy)]bis(6-chloroflavone) and 3,3'-propylenedioxybis[6-chloro-2-(2-furyl)-4H-1-benzopyran-4-one].

Abstract: The title compound 3,3'-[o-phenylenebis(methyleneoxy)]bis(6-chloroflavone), C(38)H(24)Cl(2)O(6), (I), crystallizes in the monoclinic space group C2/c, with the molecules lying across twofold rotation axes so that there is half a molecule in the asymmetric unit, while the other title compound, 3,3'-propylenedioxybis[6-chloro-2-(2-furyl)-4H-1-benzopyran-4-one], C(29)H(18)Cl(2)O(8), (II), crystallizes in monoclinic space group P2(1)/n with one molecule in the asymmetric unit. In both compounds, the benzopyran moiety is nearly planar, with dihedral angles between the two fused rings of 1.43 (8) degrees in (I), and 2.54 (7) and 3.00 (6) degrees with respect to the benzopyran moieties in the two halves of (II). The furan rings are twisted by 8.3 (1) and 8.4 (1) degrees in the two halves of (II). In both compounds, the molecular structure is stabilized by intramolecular C-H.O hydrogen bonds, while the crystal packing is stabilized by C-H.Cl and C-H.O intermolecular hydrogen bonds in (I) and (II), respectively.

6-(4-Chloro­phenyl)-4-[4-(di­methyl­amino)­phenyl]-2-(pyrrolidin-1-yl)­nicotino­nitrile

Abstract: The title compound, C24H23ClN4, crystallizes in space group P\overline 1, with two crystallographically independent mol­ecules in the asymmetric unit. In both mol­ecules, the pyrrolidine ring adopts a half-chair conformation. The molecular packing in the crystal is stabilized by intermolecular C—H⋯N hydrogen bonds, through the formation of hydrogen-bonded molecular chains.

6-(4-Methoxy­phenyl)-4-phenyl-2-(pyrrolidin-1-yl)­nicotino­nitrile

Abstract: The pyrrolidine ring in the title mol­ecule, C23H21N3O, adopts a half-chair conformation. In the solid state, C—H⋯N intermolecular hydrogen bonds link inversion-related mol­ecules, forming cyclic dimers. The structure is further stabilized by weak C—H⋯O hydrogen bonds and van der Waals forces.

4-Chloro-2-(4-chloro­phenyl)-1-formyl-1,2-di­hydro­quinoline

Abstract: The di­hydro­pyridine ring of the title mol­ecule, C16H11Cl2NO, adopts a half-chair conformation. The chloro­phenyl ring is perpendicular to the mean plane through the di­hydro­quinoline moiety. The CHO group is involved in C—H⋯O intermolecular hydrogen bonds.

6,6′‐Di­chloro‐3,3′‐(butane‐1,4‐diyl­dioxy)­diflavone

Abstract: Molecules of the title compound, C34H24Cl2O6, lie across crystallographic inversion centres. The flavone moiety is slightly folded, with the benzene and di­hydro­pyrone rings making a dihedral angle of 2.5 (2)°. In the crystal, the mol­ecules exist as cyclic intermolecular C—H⋯Cl hydrogen-bonded dimers. The structure is further stabilized by van der Waals interactions.

Use of π–π forces to steer the assembly of chromone derivatives into hydrogen bonded supramolecular layers: crystal structures and Hirshfeld surface analyses

Abstract: Two chromone derivatives C11H10O3 (1) and C11H10O2 (2) have been synthesized and characterized by X-ray structural studies with a detailed analysis of the Hirshfeld surfaces and fingerprint plots facilitating a comparison of intermolecular interactions in building different supramolecular architectures. The title compounds are associated through π–stacking interactions and the linear stacking of π–π forces can be thought as the influencing agent for the organization of the title compounds into hydrogen bonded supramolecular layers and are responsible as well for the strengthening of the molecular assembly. Investigation of the intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that more than two-thirds of the close contacts are associated with weak interactions. The fingerprint plots demonstrate that these weak interactions are important for both local and crystal packing. A comparison of the Hirshfeld surface in the compounds with similar substituted chromone derivatives in the Cambridge Structural Database (CSD) has been presented.

Molecular design of mononuclear complexes of acyclic Schiff-base ligands

Abstract: Data on molecular design of various types of mononuclear complexes of Schiff bases are generalized. Factors for variation of fine structure of Schiff-base ligand systems (metallocycle sizes and their number, nature of donor centers, aldehyde and amine fragments, co-ligands) are examined. A systematization of Salen complexes is offered. Electronic configurations of p- and d-metals in the coordination and organometallic compounds are taken into account in a series of chelate structures. Non-standard structures are emphasized, including various ligand chelates and molecular complexes.

FT-Raman, FT-IR spectral and DFT studies on 6, 8-dichloroflavone and 6, 8-dibromoflavone

Abstract: In this study, experimental and theoretical vibrational spectral results of the molecular structures of 6,8-dichloroflavone (6,8-dcf) and 6,8-dibromoflavone (6,8-dbf) are presented. The FT-IR and FT-Raman spectra of the compounds have been recorded together between 4000 and 400 cm−1 and 3500–5 cm−1 regions, respectively. The molecular geometry and vibrational wavenumbers of 6,8-dcf and 6,8-dbf in their ground state have been calculated by using DFT/B3LYP functional, with 6-31 + + G(d,p) basis set used in calculations. All calculations were performed with Gaussian03 software. The obtained vibrational wavenumbers and optimized geometric parameters were seen to be in good agreement with the experimental data. Scale factors have been used in order to compare how the calculated and experimental data are in agreement. Theoretical infrared intensities are also reported. Copyright © 2009 John Wiley & Sons, Ltd.