A facile approach for the syntheses of regioselective meso- mono, di (cis and trans), and tri formylthien-2-ylporphyrins from meso-tetrathien-2-ylporphyrin (ThP) is presented. The synthesized meso- mono formylthien-2-ylporphyrin ThP-CHO was further functionalized to 5-((5-terpyridinyl)thien-2-yl)-10,15,20-tris(thien-2-yl)porphyrin (ThP-TPy) and Porphyrin-Corrole (Por-Cor) dyad. The influence of formyl substitution and further functionalization on meso- thien-2-yl ring(s) with porphyrin central pi-system is examined through UV-Vis absorption, H-1 NMR spectroscopy and electrochemical studies. The red shift of Soret band and Q bands in the absorption spectrum and the redox potentials are shown to be dependent on the number of substitution (ThP-CHO, 424 nm < ThPt-(CHO)(2) and ThPc-(CHO)(2), 425 nm < ThP(CHO)(3), 427 nm). The significant variation in redox potentials and distinct bathochromic shift in the absorption bands in the series of formyl derivatives, ThP-TPy and Por-Cor dyad have been explained based on the near-planar orientation of the meso-thienyl groups with the porphyrin core.

Imine-bridged meso-meso and beta-meso unsymmetrical thien-2-yl porphyrin dyads were synthesized by condensation of meso- and beta-formyl derivatives of 5,10,15,20-tetrakis(3-methylthien-2-yl)porphyrinato nickel (II), Ni3MeThP with 5-(5-Aminothien-2-yl)-10,15,20-triphenylporphyrinato nickel(II), Ni5AThPP in the presence of lanthanum(III)triflate catalyst in toluene at 120 C-degrees for 8 h. The structural, photophysical, and redox properties were investigated by H-1 NMR, UV/Vis spectral, and electrochemical analysis. The near coplanarity of the linker thien-2-yl group with the central porphyrin pi-system, which can influence the electron delocalization of these molecules, is explained using electronic spectroscopy and cyclic voltammetry. The stronger electronic interaction between the two porphyrin units and the increased nonplanarity of the macrocycle brought about by the beta-meso imine bridging is indicated by the larger shift of redox potentials in the dyad-2 as compared to the dyad-1 system. The results of the present investigation reveal that the two distinct porphyrin units in dyads interact via their near planar thien-2-yl linker.

To examine the influence of molecular planarity and conjugation effects on physicochemical properties of porphyrin pi-system through meso-thienyl ring, a new class of anthracene and pyrene appended trans-ThPPZn(II)-An and trans-ThPPZn(II)-Py porphyrins have been synthesized. An efficient and facile methodology is adopted for the synthesis of trans-5NThPPM and trans-5AThPPM (where M = H-2, Cu(II), Ni(II), Zn(II)) porphyrins from 5(5-nitro-2-thienyl)dipyrromethane. The H-1 NMR spectra of the synthesized porphyrins showed two signals of equal intensity corresponding to the pyrrolyl beta-protons, which evidenced the structure of trans-isomers. Electronic spectroscopy and cyclic voltammetry explain the near co-planarity of the thien-2-yl group with the central porphyrin pi-system which can influence the electron delocalization on these molecules. The present study reveals the existence of resonance interaction between porphyrin core and anthracene/pyrene moiety in their thien-2-yl bridged conjugates.

The effect of substituents at the meso-position on the electronic and stereochemical properties of thienyl-porphyrins has been investigated by analyzing the spectra of series of porphyrins. The role of conformation in dictating the extent of electronic properties have been analysed both by electronic spectroscopy and H-1 NMR spectroscopy. Changes in the electronic properties of the thienylporphyrins by bringing the conformational changes by protonation at the core and perbromination at the periphery of the macrocycle have been related to the properties of chlorophyll. (C) 2014 Elsevier B.V. All rights reserved.

The usefulness of heterocyclic chalcone derivative as a therapeutic target in controlling hypertension and its site specific binding interaction with model transport protein to get a clear picture about its delivery mechanism.

The present study embodies the detail DNA binding interaction of a potential bioactive quinoline appended chalcone derivative (E)-3-(anthracen-10-yl)-1-(6,8-dibromo-2-methylquinolin-3-yl)prop-2-en-1-one (ADMQ) with calf thymus DNA (ctDNA) and its consequences by UV-Vis absorption, steady state fluorescence spectroscopy, fluorescence anisotropy, circular dichromism, helix melting, agarose gel electrophoresis, molecular docking, Induced Fit Docking (IFD) and molecular dynamics (MD) simulation. The UV-Vis absorption and fluorescence study reveal that the molecule undergoes considerable interaction with the nucleic acid. The control KI quenching experiment shows the lesser accessibility of ADMQ molecule to the ionic quencher (I-) in presence of ctDNA as compared to the bulk aqueous phase. Insignificant change in helix melting temperature as well as in circular dichromism (CD) spectra points toward non-covalent groove binding interaction. The moderate rotational confinement of this chalcone derivative (anisotropy = 0.106) trapped in the nucleic acid environment, the comparative displacement assay with well-known minor groove binder Hoechst 33258 and intercalator Ethidium Bromide establishes the minor groove binding interactions of the probe molecule. Molecular docking, IFD and MD simulation reveal that the DNA undergoes prominent morphological changes in terms of helix unwinding and bending to accommodate ADMQ in a crescent shape at an angle of 110 in a sequence specific manner. During interaction, ADMQ rigidifies and bends the sugar phosphate backbone of the nucleic acid and thereby shortens its overall length by 3.02 angstrom. Agarose gel electrophoresis experiment with plasmid pBR 322 reveals that the groove binded ADMQ result in a concentration dependent cleavage of plasmid DNA into its supercoiled and nicked circular form. The consolidated spectroscopic research described herein provides quantitative insight into the interaction of a heterocyclic chalcone derivative with relevant target nucleic acid, which may be useful for the future research on chalcone based therapeutic agents. (C) 2015 Elsevier B.V. All rights reserved.

The difference in the site of electrophilic nitration of meso-tetra-thien-2-yl- and thien-3-yl-porphyrins is explained based on the difference in extended conjugation between porphyrin core and meso-thienyl rings. The significance of resonance in dictating the site of substitution is also explained based on the behavior of tetrakis(5-bromothien-2-yl)porphyrin toward electrophilic nitration. Three new beta-1-acetyl-2-oxopropyl-substituted porphyrins are synthesized by Michael addition of acetylacetone group on pyrrole beta-nitroporphyrins. The photosensitizing properties of these porphyrins is investigated using porphyrin-TiO2 composites in the degradation of 4-nitrophenol. The results showed the importance of the effect of the position of sulfur on the thienyl ring and the orientation of meso-thienyl groups with the central macrocyclic ring of porphyrins in deciding its efficiency as photosensitiser. (C) 2015 Elsevier B.V. All rights reserved.

In a new concept, an iodine loaded amine functionalized MOF was employed as a syringe pump for the slow release of iodine as a catalyst in the synthesis of thienyl dipyrromethanes under ambient conditions and turned out to be successful. The catalytic activities were compared with an isoreticular non-functionalized MOF and other conventional catalysts.

The role of conformation of the linker groups at the meso-position of meso-(5-aminothien-2-yl)porphyrins and its ferrocene coupled dyad and triads on the electronic, electrochemical and photophysical properties has been investigated. An efficient and facile methodology is adopted for the synthesis of 5-aminothien-2-ylporphyrins and their ferrocene appended dyad and triads. The possible nearly in-plane arrangement of the thien-2-yl ring with the porphyrin π-system influences the role of ferrocene moiety on the fluorescence behaviour of porphyrin macrocycle. The present study supports the presence of interaction between ferrocene and porphyrin units in their thien-2-yl bridged conjugates.

An improved methodology is reported for the synthesis of 2‐nitro‐7,8,17,18‐tetrabromo‐5,10,15,20‐tetraphenylporphyrin by the β‐mononitration of 2,3,12,13‐tetrabromo‐5,10,15,20‐tetraphenylporphyrin using 50% HNO3. The copper derivative of this compound showed the expected trend in redox potentials where the free‐base form showed an opposite one on comparing with the corresponding non‐nitro analogs. This opposite trend is ascribed to the role of nitro group in dictating the extent of nonplanarity of the porphyrin as indicated by the electronic and 1H NMR spectral studies.

The present study epitomizes the design, synthesis, photophysics, solvation, and interaction with calf-thymus DNA of a potential antitumor, anticancer quinoline-appended chalcone derivative, (E)-3-(anthracen-10-yl)-1-(6,8-dibromo-2-methylquinolin-3-yl)prop-2-en-1-one (ADMQ) using steady state absorption and fluorescence spectroscopy, molecular modeling, molecular docking, Fourier-transform infrared spectroscopy (FTIR), molecular dynamics (MD) simulation, and gel electrophoresis studies. ADMQ shows an unusual photophysical behavior in a variety of solvents of different polarity. The dual emission has been observed along with the formation of twisted intramolecular charge transfer (TICT) excited state. The radiationless deactivation of the TICT state is found to be promoted strongly by hydrogen bonding. Quantum mechanical (DFT, TDDFT, and ZINDO-CI) calculations show that the ADMQ is sort of molecular rotor which undergoes intramolecular twist followed by a complete charge transfer in the optimized excited state. FTIR studies reveals that ADMQ undergoes important structural change from its native structure to a beta-hydroxy keto form in water at physiological pH. The concentration-dependent DNA cleavage has been identified in agarose gel DNA electrophoresis experiment and has been further supported by MD simulation. ADMQ forms hydrogen bond with the deoxyribose sugar attached with the nucleobase adenine DA-17 (chain A) and result in significant structural changes which potentially cleave DNA double helix. The compound does not exhibit any deleterious effect or toxicity to the E. coli strain in cytotoxicity studies. The consolidated spectroscopic research described herein can provide enormous information to open up new avenues for designing and synthesizing chalcone derivatives with low systematic toxicity for medicinal chemistry research.

Two series of new quinolinyl chalcones containing a pyrazole group, 3a–f and 4a–r, have been synthesized by Claisen–Schmidt condensation of the derivatives of 2-methyl-3-acetylquinoline with either substituted 1,3-diphenyl-1H-pyrazole-4-carbaldehyde or 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde in 76–93% yield under ultrasonic method. The compounds were characterized using IR, 1H NMR and ESI-MS spectroscopic methods and, for representative compounds, by X-ray crystallography. An E-configuration about the CC ethylene bond has been established via 1H NMR spectroscopy and X-ray crystallography. These compounds show promising anti-microbial properties, with 4a and 3e being the most potent against bacterial and fungal strains, respectively and the methoxy substituted compounds showed moderate anti-oxidant activity.

Two independent molecules comprise the asymmetric unit of the title compound, C20H17NO, which differ in the orientation of the terminal phenyl ring with respect to the quinoline ring [the dihedral angles are 75.72 (11) and 84.53 (12)degrees for the two molecules]. The conformation about each of the ethylene bonds [1.329 (3) and 1.318 (3) angstrom] is E. The crystal structure features a combination of C-H center dot center dot center dot N, C-H center dot center dot center dot pi and pi-pi contacts [inter- centroid between the phenyl ring and the quinoline benzene ring is 3.6024 (19) angstrom], generating a threedimensional network.

In the title compound, C24H19NOS, the quinoline residue (r.m.s. deviation = 0.018 angstrom) is essentially orthogonal to both the phenyl [dihedral angle = 88.95 (8)degrees] and 2-thienyl [81.98 (9)degrees] rings. The carbonyl O atom lies to one side of the quinoline plane, the carbonyl C atom is almost coplanar and the remaining atoms of the chalcone residue lies to the other side, so that overall the molecule has an L-shape. The conformation about the ethylene bond [1.340 (2) angstrom] is E. In the crystal, a supramolecular chain with the shape of a square rod aligned along the b-axis direction is sustained by CH center dot center dot center dot pi interactions, the pi-systems being the heterocyclic rings.

The pyrazole ring in the title compound, C25H19BrN2O2, is almost planar (r.m.s. deviation = 0.003 Å) and forms dihedral angles of 7.56 (13) and 56.48 (13)° with the N- and C-bound benzene rings, respectively. The prop-2-en-1-one residue has an E conformation about the C=C double bond [1.328 (4) Å] and is almost coplanar with the pyrazole ring [C—C—C—C torsion angle = −174.4 (3)°]. A twist between the prop-2-en-1-one unit and the terminal benzene ring is evident [C—C—C—C torsion angle = −15.4 (4)°]. In the crystal, molecules are consolidated into a three-dimensional architecture by C—H⋯O, C—H⋯π and π–π [centroid–centroid separation = 3.7597 (16) Å] interactions.

In the title ethanol solvate, C29H20Cl2N2O·C2H5OH, the quinolinyl residues form a dihedral angle of 46.41 (4)° with each other, and each is inclined [Cp-C-C=O and C=C-C-Cp (p = pyridyl) torsion angles = 54.8 (2) and 144.44 (19)°, respectively] with respect to the almost planar bridging prop-2-en-1-one residue [O=C-C=C torsion angle = -4.1 (3)°]. The ethanol solvent mol-ecule is disordered over two positions of equal occupancy and is located close to a centre of inversion. These mol-ecules reside in cavities defined by the organic mol-ecules, which are connected into a three-dimensional architecture by C-H⋯Cl, C-H⋯O and C-H⋯N inter-actions, as well as π-π contacts [inter-centroid distances = 3.5853 (10) and 3.8268 (11) Å], each involving pyridyl rings.

In the title solvate, C29H21ClN2O2·C3H6O, a prop-2-en-1-one bridge links two quinolinyl residues; the latter are almost perpendicular [dihedral angle = 78.27 (6)°]. The dihedral angle between the quinonyl ring system and its pendant phenyl group is 59.78 (8)°. A small twist in the bridging prop-2-en-1-one group is noted [O=C-C=C torsion angle = -10.6 (3)°]. In the crystal, a three-dimensional architecture arises as a result of C-H⋯O and π-π stacking [centroid-centroid distances = 3.5504 (12)-3.6623 (12) Å].

In the title compound, [Ni(C40H28N4S4)]·0.5C6H6, the NiIIatom is in a square-planar geometry defined by four pyrrole N atoms. There is considerable buckling in the porphyrin ring with the dihedral angles between the N4donor set and the pyrrole rings being in the range 16.24 (5)–22.47 (5)°. Each of the six-membered chelate rings is twisted about an Ni—N bond and the dihedral angles between diagonally opposite chelate rings are 21.36 (4) and 23.87 (4)°; each pair of rings is oriented in opposite directions. The methylthienyl rings are twisted out of the plane of the central N4core with dihedral angles in the range 75.98 (2)–88.70 (5)°. All four methylthienyl groups are disordered over two sets of sites, as is commonly found with such groups, with occupancies of 0.553 (8):0.447 (8), 0.579 (7):0.421 (7), 0.796 (6):0.204 (6) and 0.956 (7):0.044 (7). The benzene solvent molecule was found to be present in half-occupancy.

In the title compound, C32H21ClN2O, an almost planar (r.m.s. deviation = 0.033 Å) prop-2-en-1-one bridge links quinolinyl and benzoquinolinyl residues; the latter are twisted out of the plane of the bridge [dihedral angles = 75.94 (5) and 20.20 (5)°, respectively]. In the crystal, a three-dimensional architecture arises as a result of C-H⋯O, C-H⋯π and π-π [centroid-centroid distances involving pyridine rings = 3.5806 (7)-3.7537 (7) Å] interactions.