Nm In DMF Research Articles

Multi-Armed Star-Shaped Block Copolymers of Poly(ethylene glycol)-Poly(furfuryl glycidol) as Long Circulating Nanocarriers.

Multi-arm star-shaped block copolymers with precisely tuned nano-architectures are promising candidates for drug delivery. Herein, we developed 4- and 6-arm star-shaped block copolymers consisting of poly(furfuryl glycidol) (PFG) as the core-forming segments and biocompatible poly(ethylene glycol) (PEG) as the shell-forming blocks. The polymerization degree of each block was controlled by adjusting the feeding ratio of a furfuryl glycidyl ether and ethylene oxide. The size of the series of block copolymers was found to be less than 10 nm in DMF. In water, the polymers showed sizes larger than 20 nm, which can be related to the association of the polymers. The star-shaped block copolymers effectively loaded maleimide-bearing model drugs in their core-forming segment with the Diels-Alder reaction. These drugs were rapidly released upon heating via a retro Diels-Alder step. When the star-shaped block copolymers were injected intravenously in mice, they showed prolonged blood circulation, with more than 80% of the injected dose remaining in the bloodstream at 6 h after intravenous injection. These results indicate the potential of the star-shaped PFG-PEG block copolymers as long-circulating nanocarriers.

A coumarin coupled electron donor-acceptor dyad for cascade detection of aluminium ions and explosive nitroaromatic compounds

A coumarin coupled electron donor–acceptor dyad (HL) has been synthesized and characterized by different conventional techniques. Details spectroscopic investigation has been carried out to understand the photophysical behavior of as-prepared HL. The UV–visible spectral behavior of HL is found to be intramolecular charge transfer in nature and shows broadband, having maxima at 432 nm with a shoulder peak around 348 nm in DMF. The emission spectrum of HL also gives broadband, having maxima located at 480 nm in DMF. Further, HL is employed for the cascade detection of Al3+ ions (ON) and picric acid (PA, OFF) in DMF-H2O (7:3, v/v) media. A colorimetric change from yellow to colorless is observed in the presence of Al3+ ions. A significant fluorescence enhancement is observed due to the well coordination of Al3+ ions with HL. A visual bluish-green color could be seen under 365 nm UV light irradiation, which is also well supported by the color chromaticity diagram. The fluorescence of the HL-Al3+ complex is quenched in the presence of PA among all the tested nitroaromatic compounds. The sensitivity of HL and HL-Al3+ complex towards detection of Al3+ ions and PA can be possible down to 0.638 μM and 0.623 µM, respectively. The developed chemosensor is employed for the practical application for mapping Al3+ ions in the living cell. The performance of HL toward Al3+ ions proved that it could be exploited as a signal tool for environmental and biological samples.

Wheat straw cellulose based fluorescent probe cum bioadsorbents for selective and sensitive alleviation of uranium(VI) in waste water

Twin functional ecofriendly fluorescent probe and bioadsorbents were fabricated from wheat straw (WS) for detection and alleviation of hazardous uranyl ions from wastewater. Cellulose nanofibers (CFs) were isolated from WS using alkaline steam explosion and were converted into cellulose dialdehyde (DCF) via selective oxidation followed by conversion to Fluorescent Schiff base cellulose fibres (FSCF) by condensation with L-Arginine, a natural amino acid. Fourier transform infra-red spectroscopy (FTIR), X-Ray Diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectrometer (EDX) and thermo-gravimetric analysis (TGA) established formation of Schiff base evenly on CFs yielding robust, crystalline and thermally stable fibrous bioadsorbents. FCSF exhibited affinity for uranyl ions in presence of competing ions and linear increase in fluorescent intensity with concentration at 561 nm when excited at 279 nm in DMF with a low limit of detection (LOD) of 8.09 μM and binding constant of 10 M−1 m3. Under optimised conditions, adsorption studies revealed suitability of Pseudo-second order kinetics with maximum adsorption capacity of 192.7 mg g−1 and Langmuir isotherm confirming chemisorption of U(VI) ions. FSCF exhibited 97% adsorption efficiency after 5 cycles when tested for reusability. The results demonstrated potential application of FSCF for probing and removal of uranyl ions from wastewater.

Solvent Effects on the UV-Visible Absorption Spectra of Some New 3-Methyl-5-(Phenylamino)-4-((4-Phenylazo-Phenyl)Azo)-2-Substituted Thiophene Dyes

The preparation of 3-methyl-5-(phenylamino)-4-((4-phenylazo-phenyl)azo)thiophene dyes 4a-d, having different polar groups at the second position, was described through hetero-cyclization of the precursor 4-mercapto-4-(phenylamino)-3-((4-phenylazo-phenyl)azo)but-3-en-2-one (3) with various α-chlorinated reagents. The absorption spectra of the synthesized thiophene dyes were studied in three solvents (MeOH, CHCl3, and DMF) to correlate the effect of solvent polarity as well as chemical structures on absorption in the UV–vis region. The absorption maximum (λmax) changed from 486 to 502 nm in methanol, from 502 to 512 nm in chloroform, and from 626 to 654 nm in DMF. The benzoyl group's introduction in the second position of the thiophene ring brings the absorption maxima to higher values (bathochromic shift).

Diradical Character of Neutral Heteroleptic Bis(1,2-dithiolene) Metal Complexes: Case Study of [Pd(Me2timdt)(mnt)] (Me2timdt = 1,3-Dimethyl-2,4,5-trithioxoimidazolidine; mnt2- = 1,2-Dicyano-1,2-ethylenedithiolate).

The reaction of the bis(1,2-dithiolene) complex [Pd(Me2timdt)2] (1; Me2timdt•– = monoreduced 1,3-dimethyl-2,4,5-trithioxoimidazolidine) with Br2 yielded the complex [Pd(Me2timdt)Br2] (2), which was reacted with Na2mnt (mnt2– = 1,2-dicyano-1,2-ethylenedithiolate) to give the neutral mixed-ligand complex [Pd(Me2timdt)(mnt)] (3). Complex 3 shows an intense solvatochromic near-infrared (NIR) absorption band falling between 955 nm in DMF and 1060 nm in CHCl3 (ε = 10700 M–1 cm–1 in CHCl3). DFT calculations were used to elucidate the electronic structure of complex 3 and to compare it with those of the corresponding homoleptic complexes 1 and [Pd(mnt)2] (4). An in-depth comparison of calculated and experimental structural and vis–NIR spectroscopic properties, supported by IEF-PCM TD-DFT and NBO calculations, clearly points to a description of 3 as a dithione-dithiolato complex. For the first time, a broken-symmetry (BS) procedure for the evaluation of the singlet diradical character (DC) of heteroleptic bis(1,2-dithiolene) complexes has been developed and applied to complex 3. The DC, predominant for 1 (nDC = 55.4%), provides a remarkable contribution to the electronic structures of the ground states of both 3 and 4, showing a diradicaloid nature (nDC = 24.9% and 27.5%, respectively). The computational approach developed here clearly shows that a rational design of the DC of bis(1,2-ditiolene) metal complexes, and hence their linear and nonlinear optical properties, can be achieved by a proper choice of the 1,2-dithiolene ligands based on their electronic structure.

BODIPY-Hg2+ Complex: A Fluorescence "Turn-ON" Sensor for Cysteine Detection.

A BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) based pioneering sensing material (HLPy) having 2-amino pyridine as receptor was synthesized and used for the selective detection of Hg2+ ions. The synthesized HLPy features a high affinity towards Hg2+ (ka = 2.04 × 105 M-1), accompanied by effective quenching of fluorescence in DMF:H2O (1:9 v/v, 10 mM HEPES buffer, pH 7.4) with 54 nM limit of detection (LOD). The emission titration experiments (Job's plot) in the presence of varying mole-fraction of Hg2+ ions reveals the formation of non-fluorescent 2:1 coordination complex [Hg(LPy)2]. The resulting non-fluorescent [Hg(LPy)2] was thoroughly characterized using various spectroscopic techniques and analyses. Interestingly, the non-fluorescent complex [Hg(LPy)2] is able to specifically respond towards Cys over other biothiols and amino acids through a reversible de-complexation mechanism. As a result, the remarkable recovery of the fluorescence can be observed. The limit of detection (LOD) for Cys detection is estimated to be 29 nM in DMF:H2O (1:9 v/v, 10 mM HEPES buffer, pH 8.0). The reversibility and reusability of [Hg(LPy)2] were achieved by the sequential addition of Cys and Hg2+ ions up to five cycles. Moreover, the removal of Hg2+ ions up to 89% from aqueous samples using HLPy was successfully demonstrated.

Synthesis of novel benzocoronene tetracarboxdiimides for fluorescent imaging of latent fingerprints

Benzocoronene tetracarboxdiimide (CDI 1a) is prepared by ring annulation of perylene diimide via Suzuki coupling and sunlight-driven photocyclization reactions. Oxidative photocyclization predominantly occurred at the carbon position ortho to the CHO group. It is demonstrated to undergo aggregation in 30 % DMF: H2O with degree of aggregation and Franck-Condon factor value reaches 0.94 and 0.64, respectively. The emission spectrum of CDI 1a shows monomer band at 568 nm in DMF and aggregation band at 688 nm in 30 % DMF: H2O with onset of emission color from yellow to reddish-pink. These near-IR fluorescent aggregates are proved to be an ideal fluorescent material for imaging LFPs using solution and powder-dusting methods. The papillary ridges detail (1st and 2nd level of information) on various non-porous surfaces (aluminum, steel, compact disc, glass etc.) and porous surfaces (paper, floor tiles) are presented by CDI 1a.

DEVELOPMENT AND VALIDATION OF UV SPECTROPHOTOMETRICMETHOD FOR QUANTITATIVE ESTIMATION OF GLIPIZIDEIN PHARMACEUTICAL DOSAGE FORM

Objective: The present work is aimed to develop a simple, rapid, selective and economical UV spectrophotometric method for quantitative determination of Glipizideinbulk and pharmaceutical dosage form.
 Methods: In this method Dimethyl Form amide (DMF) was used as solvent, the absorption maxima was found to be275 nm in DMF. The developed method was validated for linearity, accuracy, precision, ruggedness, robustness, LOD and LOQ in accordance with the requirements of ICH guideline.
 Results: The linearity was found to be 10-60 µg/ml having linear equation y=0.017x-0.006 with correlation coefficient of 0.997. The% recovery was found to be in the range of 98.7-100%. The % RSD for intra-day and inter-day precision was found to be 0.569923 and 0.40169 respectively. The limit of detection (LOD) and limit of quantification (LOQ) was found to be3.06 µg/ml and 9.27 µg/ml respectively.
 Conclusion: The developed method was validated as per ICH Q2(R1) guidelines. The novel method is applicable for the analysis of bulk drug in its pharmaceutical dosage form.

Synthesis of Platinum-Containing Conjugated Polymers Having QuinoxP* and Bipyridine Ligands. Chirality Transfer from the Phosphine Ligand to the Polymer Backbone

Platinum (Pt)-containing novel conjugated polymers, poly­(1-2a)–poly­(1-2d) having bipyridine ligands were synthesized by the Sonogashira–Hagihara coupling polymerization of [Pt­(4,4′-dibromo-2,2′-bipyridine)­((R,R)-2,3-bis­(tert-butylmethylphosphino)­quinoxaline)­(trifluoromethanesulfonate)2] (1) coordinated with 4,4′-dibromo-2,2′-bipyridine/(R,R)-2,3-bis­(tert-butylmethylphosphino)­quinoxaline [(R,R)-QuinoxP*] and 1,4-diethynylbenzene (2a), 1,4-diethynyl-2,5-bis­(heptyloxy)­benzene (2b), 1,4-diethynyl-2,5-bis­(2-ethylhexyloxy)­benzene (2c), and 1,4-diethynyl-2,5-bis­(2-(2-methoxyethoxy)­ethoxy)­benzene (2d). Poly­(1-2d) exhibited circular dichroism signals derived from (R,R)-QuinoxP* and the conjugated main chain around 290 and 440 nm in DMF, respectively. The simulated CD spectroscopic pattern of a low molecular model compound, M1-Pt, agreed well with the observed spectra. The TEM images of poly­(1-2d) in the solid state exhibited dispersed patterns with sizes around 10 nm. Concentrated solutions of polymer 1-2d in DMF and CHCl3 partly exhibited patterns assignable to the formation of lyotropic liquid crystals.

Preparation and properties of polyimides having porphyrin moieties for heavy metals removal

A tetramine monomer containing porphyrin moiety is prepared in high purity by the propionic acid-mediated condensation of pyrrole with 4-cyanobenzaldehyde and then reduction in the tetracyano intermediate. The thermally stable porphyrin-based polyimides (PI)s are prepared using tetramine and four aromatic tetracarboxylic dianhydrides via a two-step method in quantitative yields with inherent viscosities of 0.34–0.63 dL/g. The PIs are soluble in some organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide and dimethyl sulfoxide. The resultant PIs had high glass transition temperatures and displayed outstanding thermal stability up to 500 °C. The resulting polymers revealed strong UV–Vis absorption band around 422 nm in DMF. Wide-angle XRD measurements exhibited that the PIs were amorphous. The polymer films had tensile strengths 101–128 MPa, elongates at break of 7–11% and tensile moduli of 2.0–2.2 GPa. One of the PIs was applied to examine the adsorption properties of two heavy metal ions (Cd2+ and Hg2+) at pH 7. The results revealed that the applied PI was an outstanding sorbent for heavy metal ions. The goal of this study is the preparation of hydrophobic PIs for ion-selective membranes and chemical sensors to adsorb of toxic heavy metals.

A naphthalimide-based fluorescent probe for the highly sensitive and selective detection of nerve agent mimic DCP in solution and vapor phase

The fluorescent probe for DCP displays excellent selectivity and sensitivity with a low detection limit of 5.5 nM in DMF.

Synthesis and dyeing performance of some amphiphilic naphthalimide azo disperse dyes on polyester fabrics

A series of monoazo disperse dyes were synthesized by coupling diazotized 4-amino-N-dodecyl-1,8-naphthalimide with N,N-dialkyl anilines and naphthol derivatives. The synthesized intermediates and the dyes were characterized using FTIR, 1H-NMR, 13C-NMR, mass spectroscopy and elemental analysis (CHN). Visible absorption spectra of the dyes were examined in solvents of different polarities. The electronic absorption spectra cover a wavelength (?max) range of 515-535 nm in DMF at uniformly absorption intensity between 1.59-3.00?104 L mol-1 cm-1. The dyes gave deep and bright intense hues of light violet, maroon, pink and neon red on polyester fabrics. The dyes generally showed good washing and perspiration rating but poor to moderate light fastness properties on woven polyester fabric and could be recommended for commercial outlets.

SYNTHESIS AND DYEING PERFORMANCE OF AZO-ANTHRAQUINONE DYES ON POLYESTER FABRICS

A series of monoazo disperse dyes based on azo-anthraquinone were synthesized by coupling diazotized 1-aminoanthraquinone with pyridone derivatives. The identity of the intermediates and the resultant dyes were investigated using UV-visible, FTIR, 1H NMR, elemental analysis (CHN) and mass spectroscopy. Visible absorption spectra of the dyes were examined in solvents of different polarities. The electronic absorption spectra cover a wavelength range of 446 - 488 nm in DMF at uniformly high absorption intensity between 1.20 × 104 - 5.22 × 104 lmol-1cm-1. The dyes were applied on polyester fabrics using carrier method of dyeing to determine their buildup and the fastness properties. The results indicated very good dyeing exhaustion and good to very good to washing, perspiration, sublimation and light fastness on polyester fabrics. The remarkable degree of levelness and brightness after washing is indicative of good penetration and excellent affinity of these dyes for the polyester fabrics and can be recommended for commercial outlets.

Synthesis, optical and electrochemical abilities of highly soluble poly(epoxy-ether)s bearing perylene bisimide units and their enhanced thermal properties by curing process

Three highly fluorescent poly(epoxy-ether) containing three different units at two imide functionalities of perylene bisimide unit (PER-EP1, PER-EP2 and PER-EP3) could be efficiently synthesized in high yields, and were characterized by FT-IR, 1H NMR and 13C NMR spectroscopic techniques. Their optical properties were measured using UV–vis and emission spectroscopic methods, as well as cyclic voltammetry (CV) to analyze their electrochemical abilities. They all showed emission in the visible region. Additionally, one reversible one-electron oxidation and two reversible one-electron reductions in acetonitrile took place for the synthesized poly(epoxy-ether)s. Dihydroxy compounds containing perylene units exhibited three absorption maxima (λmax) values of 458, 489 and 524 nm in DMF owing to presence of perylene units and highly conjugated framework of π bonds. For poly(epoxy-ether)s, the functional groups influenced the conjugated systems, giving rise to the absorption peaks to shift to longer wavelengths. Fluorescence spectra of the synthesized poly(epoxy-ether)s in DMF showed emission peaks in the wavelength range of green light, and the highest value of fluorescence quantum yield was 8.2% for PER-EP1 in comparison to standard fluorescein solution. Furthermore, morphological analysis demonstrated that the synthesized poly(epoxy-ether)s possessed well-organized microstructure particles despite the linkage of the perylene bisimide core. The prepared epoxy resins were cured with p-phenylenediamine as aromatic hardener. The resulting cured epoxy resins were analyzed for their thermal properties such as thermal stability, char yield, glass transition temperature (Tg), and flame retardancy. The morphology behaviour was performed by SEM analysis on poly(epoxy-ether)s.

ESIPT clubbed azo dyes as deep red emitting fluorescent molecular rotors: Photophysical properties, pH study, viscosity sensitivity, and DFT studies

Monoazo colorants with separate inbuilt ESIPT core were selected to examine the influence of azo group para to the hydroxyl group of ESIPT core and their effect on their spectral properties. They displayed absorption maxima in the visible region around 480–493 nm. 6a exhibited a broad peak along with a bathochromic shift of 40/90 nm in the solvents DMF and DMSO due to the existence of tautomeric equilibrium. They are sensitive to basic pH with a bathochromic shift of 30 nm. They are emissive in the deep red region (565–640 nm) accompanied by a Stokes shift of 62–121 nm in DMF and DMSO. More interestingly, they showed viscosity sensitive enhancement in emission in DMF: PEG 400 system in the deep red region. 6(a–c) exhibit higher quantum yield in viscous solvent i.e. 99% PEG 400 compared to that of DMF. 6a and 6c show viscosity sensitive (x) value of 0.522 and 0.513 respectively. The enhancement of emission intensity in the viscous solvent is due to charge transfer which was elucidated by polarity plots i.e. “Lippert-Mataga”, “Mac-Rae”, “Weller's” and “Rettig's” plots. DFT and TD- DFT methods were used to correlate the experimental findings.

A dual-function colorimetric probe based on Carbazole-Cyanine dyad for highly sensitive recognition of cyanide and hypochlorous acid in aqueous media

A dual-function colorimetric probe (Cz-Cy7) with an electron-donating carbazole tethered at the central position of heptamethine cyanine was designed and synthesized, and the performance on CN− and HClO detection were systematically investigated. With the addition of CN−, Cz-Cy7 exhibited remarkable changes in both UV–vis and fluorescence spectra with a good linear relationship to CN− concentration, and a discernible color change under daylight was observed. The limit of detection for CN− was found to be 9.1 nM in DMF and 0.09 μM in DMF/H2O. Meanwhile, Cz-Cy7 exhibited a highly sensitive response to HClO in the presence of other ROS (reactive oxygen species) based on the sensing mechanism of oxidative cleavage of olefinic C = = C bond. The limit of detection for HClO was evaluated to be 14 nM in PBS buffer solution (containing 50% CH3CN). More importantly, the probe Cz-Cy7 showed good recovery and analytical precision in real water samples for both CN− and HClO detection, indicating it was feasible and reliable for practical application. Moreover, the test strips loaded with Cz-Cy7 were fabricated and validated to be a portable tool for the efficient detection of CN− and HClO by the naked eye.

Hydroxybenzo[b]quinolizinium Ions: Water-Soluble and Solvatochromic Photoacids.

It is shown by photometric and fluorimetric analysis, along with supporting theoretical calculations, that hydroxy-substituted benzo[b]quinolizinium derivatives display the characteristic features of organic photoacids. Specifically, the experimental and theoretical results confirm the strong acidity of these compounds in the excited state (pKa* < 0). The combination of the prototropic properties of 8- and 9-hydroxybenzo[b]quinolizinium with the particular solvent-solute interactions of the excited acid and its conjugate base leads to a pronounced fluorosolvatochromism, hence the emission maxima shift from 468 nm (8-hydroxybenzo[b]quinolizinium) or 460 nm (9-hydroxybenzo[b]quinolizinium) in CH3CN to 507 and 553 nm in DMF, respectively. This novel type of photoacid represents several features that may be used for applications as water-soluble fluorescent probes or as a source for the photoinduced supply of acidity.

Morphology and photophysical properties of dual-emissive hyperbranched zinc phthalocyanines and their self-assembling superstructures

Hyperbranched zinc phthalocyanines (HBZnPCs) showing dual-emissive fluorescence in N, N-dimethylformamide (DMF) solution were synthesized via a facile one-step cycloaddition of conjugated bisphthalonitrile precursors. The chemical, crystalline structures, surface morphology, and photophysical properties of synthesized HBZnPCs for different reaction times were systematically studied. It was found that HBZnPCs synthesized for 4 h exhibit the strongest dual fluorescent emission at ~440 and 690 nm in DMF, respectively, when excited at 365 nm, and micrometer scale sheet-like morphology was obtained in this case. In addition, the fluorescent emission of HBZnPCs dramatically changed in different solvents: the red emission was amplified in solvent of strong polarity, while blue emission dominated in non-co-ordinated solvent. More interestingly, we found for the first time that the fluorescence of initially “dark” H-aggregates of HBZnPCs in DMF/H2O mixed solvent was gradually recovered through self-assembling driven by the poor solvent, leading to a strong emission around 460 nm, which contributed to the formation of stable J-type superstructures.

In Situ Characterization of Binary Mixed Polymer Brush-Grafted Silica Nanoparticles in Aqueous and Organic Solvents by Cryo-Electron Tomography.

We present an in situ cryo-electron microscopy (cryoEM) study of mixed poly(acrylic acid) (PAA)/polystyrene (PS) brush-grafted 67 nm silica nanoparticles in organic and aqueous solvents. These organic-inorganic nanoparticles are predicted to be environmentally responsive and adopt distinct brush layer morphologies in different solvent environments. Although the self-assembled morphology of mixed PAA/PS brush-grafted particles has been studied previously in a dried state, no direct visualization of microphase separation was achieved in the solvent environment. CryoEM allows the sample to be imaged in situ, that is, in a frozen solvated state, at the resolution of a transmission electron microscope. Cryo-electron tomograms (cryoET) were generated for mixed PAA/PS brush-grafted nanoparticles in both N,N-dimethylformamide (DMF, a nonselective good solvent) and water (a selective solvent for PAA). Different nanostructures for the mixed brushes were observed in these two solvents. Overall, the brush layer is more compact in water, with a thickness of 18 nm, as compared with an extended layer of 27 nm in DMF. In DMF, mixed PAA/PS brushes are observed to form laterally separated microdomains with a ripple wavelength of 13.8 nm. Because of its lower grafting density than that of PAA, PS domains form more or less cylindrical or truncated cone-shaped domains in the PAA matrix. In water, PAA chains are found to form a more complete shell around the nanoparticle to maximize their interaction with water, whereas PS chains collapse into the core of surface-tethered micelles near the silica core. The cryoET results presented here confirm the predicted environmentally responsive nature of PAA/PS mixed brush-grafted nanoparticles. This experimental approach may be useful for the design of future mixed brush-grafted nanoparticles for nano- and biotechnology applications.

Polypyridyl iron(II) complexes showing remarkable photocytotoxicity in visible light

Iron(II) complexes of polypyridyl ligands (B), viz. [Fe(B)2]Cl2 (1 and 2) of N, N, N-donor 2-(2-pyridyl)-1,10-phenanthroline (pyphen in 1) and 3-(pyridin-2-yl)dipyrido[3,2-a:2’,3’-c]phenazine (pydppz in 2), are prepared and characterized. They are 1:2 electrolytes in aqueous DMF. The diamagnetic complexes exhibit metal to ligand charge transfer band near 570 nm in DMF. The complexes are avid binders to calf thymus DNA giving binding constant (K b) values of ∼106 M−1 suggesting significant intercalative DNA binding of the complexes due to presence of planar phenanthroline bases. Complex 2 exhibits significant photocytotoxicity in immortalized human keratinocyte cells HaCaT and breast cancer cell line MCF-7 giving IC50 values of 0.08 and 13 μM in visible light (400–700 nm). Complex 2 shows only minor dark toxicity in HaCaT cells but is non-toxic in dark in MCF-7 cancer cells. The light-induced cellular damage follows apoptotic pathway on generation of reactive oxygen species as evidenced from the dichlorofluorescein diacetate (DCFDA) assay. Iron(II) complex of pyridyldipyridophenazine base shows remarkable photocytotoxic effect in MCF-7 and HaCaT cell lines upon visible light irradiation (400–700 nm) via apoptotic pathway on generation of reactive oxygen species.