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Designing fluorescent probes and its metal‐organic materials getting attention due to their fascinating utility in several fields from material to biology. Here, we synthesized N‐phenyl glycine substituted four new fluorescent probes viz. (2‐cyanophenyl)glycine [HL1], (5‐chloro‐2‐cyanophenyl)glycine [HL2], (4‐chloro‐2‐cyanophenyl)glycine [HL3], (2‐cyano‐3‐fluorophenyl)glycine [HL4] and investigated its properties through spectroscopic techniques. Out of all probes, HL1 displayed non‐emissive nature in the presence of water and uniquely detect the percentage of methanol in the methanol‐water mixture or vice‐versa out of the different solvent‐water mixture with the help of fluorometric technique. Furthermore, cobalt complex [Co(L1)(phen)2]ClO4 (C1) with distorted octahedral geometry has been synthesized by using HL1. The emissive nature of the complex C1 was further utilized for the selective sensing of S2− ion in the DMSO‐water mixture by quenching the fluorescence with a detection limit of 4.8 μM. The selective solvent percentage detection and anion sensing illustrate the potential efficacy of the designed sensors for analytical intent. [ABSTRACT FROM AUTHOR]

This work describes the synthesis of a series of Ru(II)‐Arene (Arene=p‐cymene, benzene) complexes using different N‐substituted tetrazole ligands and their PTA analogues. All the complexes have been characterized thoroughly using different analytical techniques. Antiproliferative activity of the synthesized complexes against different cell lines indicates remarkable activity of certain complexes up to nanomolar level. In few cases introduction of water soluble PTA (PTA = 1,3,5‐ triaza‐7‐phospha‐tricyclo‐[3.3.1.1]decane) ligand induce significant cytotoxic activity in the ruthenium complex with respect to their chloro analogues, particularly against Jurkat and MCF‐7 cell lines. Interaction with different biomolecules and stability of the RAPTA complexes have been explored in pseudo‐pharmacological conditions. [ABSTRACT FROM AUTHOR]

1,3-Dipolar cycloaddition between nickel-ligated azide in [NiL(N3)] [HL = 3-(2-diethylamino-ethylimino)-1-phenyl-butan-1-one] and two different organonitriles furnished two new square-planar complexesviz. [NiL(5-phenyltetrazolato)] and [NiL{5-(4-pyridyl)-tetrazolato}]. Both the complexes have been characterized by spectroscopic tools and single-crystal X-ray crystallography. Interaction with different biomolecules revealed that both complexes bind strongly to serum albumin proteins and show moderate catecholase-like activity by catalyzing the oxidation of 3,5-ditertbutylcatechol (3,5-DTBC). Identification of intermediates formed in catechol oxidation has been explored by ESI-MS spectrometry. [ABSTRACT FROM AUTHOR]

Four new metal complexes (one mononuclear and three dinuclear) viz . [NiL(5-phenyltetrazolato)] ( 1a ), [Ni 2 L 2 {5-(2-cyanophenyl)-tetrazolato} 2 ] ( 1b ), [Cu 2 L 2 {5-phenyltetrazolato} 2 ]·C 6 H 5 CN ( 2a ) and [Cu 2 L 2 {5-(2-cyanophenyl)-tetrazolato} 2 ] ( 2b ) [HL = 3-(2-dimethylamino-ethylimino)-1-phenyl-butan-1-one] have been synthesized by in-situ generation of tetrazolato ligands and characterized by X-ray crystallography, different spectroscopic techniques and elemental analyses. Introduction of one nitrile group in the 5-substituted phenyl ring makes the tetrazolato ligand comparatively weaker donor leading the complex to be more vulnerable towards dissociation facilitating subsequent substrate binding for catecholase oxidation study. Copper complex 2b has been found to be more active with respect to analogous nickel complex 1b as it provides the metal centered oxidation route rather than ligand centered oxidation in nickel complex. The comparative catalytic activities of complex 1b and 2b are further explored by DFT calculations which also support the experimental results. UV–Vis and fluorescence-based spectroscopic techniques revealed that two of the metal-tetrazolato complexes ( 1a and 2b ) interact with double stranded DNA via intercalation and also with serum albumin protein BSA. A comparative assessment indicated that the Ni(II)-tetrazolato complex 1a displayed superior DNA binding. The interaction of these compounds with bovine serum albumin (BSA) suggested that the Cu(II)-tetrazolato complex 2b quenched the intrinsic fluorescence of BSA in a static quenching process and shows stronger binding constant. [ABSTRACT FROM AUTHOR]

Four new ruthenium arene PTA type complexes have been synthesized using substituted picolinamide derivatives as ancillary ligands and characterized by spectroscopic methods. In one of the complexes, the ancillary ligand has shown an unprecedented valence-bond tautomerization in the presence of an ammonium salt to act as a polar neutral donor ligand making the ligand more prone towards substitution. The same compound has shown remarkable antiproliferative activity against three cancer cell lines with GI50 values comparable to Adriamycin, a known therapeutic drug. Along with this it also strongly inhibits the action of thioredoxin reductase, which might be a probable reason for the enhanced proliferative action of the valence-bond tautomerized compound. [ABSTRACT FROM AUTHOR]

In this work, four new ruthenium complexes [Ru(η6-p-cymene)(L1)Cl] 1, [Ru(η6-p-cymene)(L2)Cl] 2, [Ru(η6-p-cymene)(L3)Cl] 3 and [Ru(η6-p-cymene)(L4)Cl] 4 [HL1 = (2-cyanophenyl)glycine; HL2 = (5-chloro-2-cyanophenyl)glycine; HL3 = (2-cyano-3-fluorophenyl)glycine; HL4 = (4-cyanophenyl)glycine] were synthesized and well characterized by several spectroscopic and analytical techniques. Complexes 1 and 3 were found to be fluorescent in most of the solvents; however, 2 and 4 were found to be fluorescent mostly in EtOAc, DMF and ethanol. Amongst these four complexes, 3 has shown selective sensing against CO32− and SO42− anions by quenching of fluorescence. The LOD values are found to be in the sub-micromolar range. Investigations of the sensing mechanism performed by computation and NMR studies indicate a possible adduct formation between the NH group of the ligand and the anion(s) through hydrogen bond formation, which ultimately might lead to proton transfer to the bi-negative anion. The quantum yield of the complex 3 was found to decrease on addition of CO32− and SO42− anions from 0.46 to 0.13 and 0.12, respectively. The Job's plot indicates the binding between the probe and anion in a 1 : 1 ratio for both CO32− and SO42− anions. Along with that, all the complexes were found to be biocompatible when tested against several cell lines showing very high IC50 values. It can also be observed that 1 is capable of penetrating within the cells and can act as a cell imaging agent showing fluorescence, and thus can be used for bio-imaging purposes. [ABSTRACT FROM AUTHOR]

Crystalline copper Schiff base complexes of general formula [CuL 1 NO 3 ] n (1) and [CuL 2 Cl] (2) (where HL 1  = 1-[(3-dimethylaminopropylimino)-methyl]-naphthalen-2-ol and HL 2  = 3-[(3-dimethylamino-2,2-dimethyl-propylimino)-methyl]-naphthalen-2-ol) were prepared and well characterized. The guest, metal complexes were entrapped in the supercages of NaY zeolite (host) in the solvent phase through two stage process (i) ion exchange of the selected transition metal (Cu(II)-salt) in the porous structure and (ii) encapsulation of Schiff-base ligands (HL 1 /HL 2 ) in Cu(II) exchanged zeolite. The novel Cu(II) complexes as well as host-guest catalysts were characterized using various physicochemical [Single crystal XRD, elemental analysis, EDX, scanning electron microscopy (FE-SEM), the Brunauer-Emmet-Teller (BET) adsorption technique (N 2 gas), Inductively coupled plasma (ICP-MS), powder X-ray diffraction (PXRD), thermal analysis (TGA), cyclic voltametry] and spectroscopic techniques [ 1 H and 13 C NMR, FT-IR, ESI-MS, electro spin resonance (ESR), diffuse reflectance spectroscopy (DRS), FT-Raman and GC-MS]. Herein, this study reveals the advantage of heterogeneous catalytic methods for the stability of metal complexes into the supercages of zeolite-Y and the selective oxidation of phenol, styrene and cyclohexene in presence of H 2 O 2 at mild reaction conditions. The catalytic activities of the zeolite entrapped Cu(II) complexes were tested with their homogeneous analogous as well. The heterogeneous catalyst can be re-used after recovering for several cycles without decay of activity which was confirmed by PXRD, cyclic voltammetry, SEM and FTIR studies. [ABSTRACT FROM AUTHOR]

Three new Cu(II) complexes, [Cu(HL1)(pyridine)(H2O)](ClO4)2·2MeOH (1), [Cu2(HL1)2(NO3)2](NO3)2·3H2O (2) and [Cu(HL2)(NO3)2]·MeCN (3), have been synthesized from two Schiff base ligands [HL1 = 1-phenyl-3-((2-(piperazin-4-yl)ethyl)imino)but-1-en-1-ol and HL2 = 4-((2-(piperazin-1-yl)ethyl)imino)pent-2-en-2-ol] using the chair conformer of a flexible piperazinyl moiety. Structural analysis reveals that1and3are monomeric Cu(II) complexes consisting of five- and six-coordinate Cu(II), respectively, whereas2is a dinuclear Cu(II) complex consisting of two different Cu(II) centers, one square planar with the other distorted octahedral. Screening tests were conducted to quantify the binding of1–3towards DNA and BSA as well as the DNA cleavage activity of these complexes using gel electrophoresis. Enzyme kinetic studies were also performed for the complexes mimicking catecholase-like activities. Antibacterial activities of these complexes were also examined towards Methicillin-ResistantStaphylococcus aureusbacteria. The results reflect that2is more active than the monomeric complexes, which is further corroborated by density functional theory study. [ABSTRACT FROM AUTHOR]