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Ruthenium(ii) and iridium(iii) bis(terpyridine) complexes were prepared with maleimide functionalities in order to site-specifically modify yeast iso-1 cytochrome c possessing a single cysteine residue available for modification (CYS102). Single X-ray crystal structures were solved for aniline and maleimide Ru(ii) 3 and Ru(ii) 4, respectively, providing detailed structural detail of the complexes. Light-activated bioconjugates prepared from Ru(ii) 4 in the presence of tris(2-carboxyethyl)-phosphine (TCEP) significantly improved yields from 6% to 27%. Photoinduced electron transfer studies of Ru(ii)-cyt c in bulk solution and polymer membrane encapsulated specimens were performed using EDTA as a sacrificial electron donor. It was found that membrane encapsulation of Ru(ii)-cyt c in PS140-b-PAA48 resulted in a quantum efficiency of 1.1 ± 0.3 × 10-3, which was a two-fold increase relative to the bulk. Moreover, Ir(iii)-cyt c bioconjugates showed a quantum efficiency of 3.8 ± 1.9 × 10-1, equivalent to a ～640-fold increase relative to bulk Ru(ii)-cyt c.

In the present paper, a bis-terpyridyl Eu3+ complex (bis-terpyridyl Eu3+-complex L1) was synthesized through the coordination between Eu3+ and a compound L1 with an azobenzene-functionalized chain between the two terpyridi

Several transition metal complexes based on 2,3-bis(2,4,5-trimethyl-3- thienyl)maleic anhydride (DTE) bearing terpyridine (TPY) have been designed and synthesized. Furthermore, the photochromism of the free ligand and the influence of transition metal moi

A novel phenylene viologen functionalized bis(terpyridine) is synthesized and characterized with 1HNMR and Maldi-tof-MS. This rod-like and π-conjugated molecule, 1,1'-[4'-(4-phenyl)-2,2:6′,2″- terpyridine-4,4′-bipyridine-1,1′-diium dichloride (

The 4-amino-1,8-naphthalimide-Tr?ger's base fluorophore, TBNap-TPy, adorned with phenyl-terpyridine moiety was synthesised and assessed for its aggregation-induced emission (AIE) behaviour. TBNap-TPy was further employed as a fluorescent sensor for the di

We report here a series of coordinatively-saturated and thermodynamically stable luminescent [Ln(dtntp)(H2O)] [Ln(III) = Eu (1), Tb (2), Gd (3), Sm (4) and Dy (5)] complexes using an aminophenyl-terpyridine appended-DTPA (dtntp) chelating ligand as cell imaging and photocytotoxic agents. The N,N″-bisamide derivative of H5DTPA named as dtntp is based on 4′-(4-aminophenyl)-2,2′:6′,2″-terpyridine conjugated to diethylenetriamine-N,N′,N″-pentaacetic acid. The structure, physicochemical properties, detailed photophysical aspects, interaction with DNA and serum proteins, and photocytotoxicity were studied. The intrinsic luminescence of Eu(III) and Tb(III) complexes due to f → f transitions used to evaluate their cellular uptake and distribution in cancer cells. The solid-state structure of [Eu(dtntp)(DMF)] (1·DMF) shows a discrete mononuclear molecule with nine-coordinated {EuN3O6} distorted tricapped-trigonal prism (TTP) coordination geometry around the Eu(III). The {EuN3O6} core results from three nitrogen atoms and three carboxylate oxygen atoms, and two carbonyl oxygen atoms of the amide groups of dtntp ligand. The ninth coordination site is occupied by an oxygen atom of DMF as a solvent from crystallization. The designed probes have two aromatic pendant phenyl-terpyridine (Ph-tpy) moieties as photo-sensitizing antennae to impart the desirable optical properties for cellular imaging and photocytotoxicity. The photostability, coordinative saturation, and energetically rightly poised triplet states of dtntp ligand allow the efficient energy transfer (ET) from Ph-tpy to the emissive excited states of the Eu(III)/Tb(III), makes them luminescent cellular imaging probes. The Ln(III) complexes show significant binding tendency to DNA (K ~ 104 M?1), and serum proteins (BSA and HSA) (K ~ 105 M?1). The luminescent Eu(III) (1) and Tb(III) (2) complexes were utilized for cellular internalization and cytotoxicity studies due to their optimal photophysical properties. The cellular uptake studies using fluorescence imaging displayed intracellular (cytosolic and nuclear) localization in cancer cells. The complexes 1 and 2 displayed significant photocytotoxicity in HeLa cells. These results offer a modular design strategy with further scope to utilize appended N,N,N-donor tpy moiety for developing light-responsive luminescent Ln(III) bioprobes for theranostic applications.

In this paper, a novel catalyst is designed, synthesized and characterized based on the functionalization of magnetic iron oxide nanoparticles by terpyridine as a ligand for the immobilization of palladium. The catalyst is fully characterized by several c

Several phenyl-substituted 2,2′:6′,2″-terpyridines (tpy) were synthesized and it was found that 4′-phenyl tpy (ptp, 3) exhibited the most effective fluorescence, whose quantum yield was up to 0.64 in cyclohexane. For further study on tuning the fluorescence properties of ptp, different substituents were introduced into the p-position of the phenyl group. While Br- 10, Cl- 11, and CH3-ptp 12 showed their absorption and fluorescence in the same region as 3, those of NH2- 14 and Me2N-ptp 15 were observed at much longer wavelengths. In addition, fluorescence maxima of 14 and 15 showed large (> 130 nm) solvent dependence. The difference between ground and excited state dipole moment (Δμ) for 15 was estimated to be 15.2 D by the Lippert-Mataga equation, indicating the intramolecular charge transfer (ICT) process. Semi-empirical MO calculation (MOPAC/AM1) demonstrated that the HOMO-1, HOMO and LUMO of 3, 10-12 were mainly localized on the phenyl (πph), tpy (πtpy) and tpy (π*tpy) part, respectively, indicating that the lowest energy absorption band of 3, 10-12 was the local excitation (πtpy-π*tpy). In the case of 14 and 15, which have an electron-donating substituent, πph instead of πtpy became the HOMO. Thus, the lowest energy absorption of 14 and 15 was an ICT transition (πph-π*tpy), and a large red shift of the fluorescence occurred. In these compounds, the energy level of πph is controlled without affecting that of πtpy and π*tpy, suggesting a novel approach for tuning the color of fluorescence.

We fabricated photoelectron conversion system with porphyrin-terminated "molecular wires" on an ITO surface synthesized using stepwise metal-terpyridine complexation reactions. The efficiency and the electrode potential singniflcantly depended on the meta

A new fluorescent sensor based on benzothiazole-terpyridine conjugate is reported. It functions as a fluorescent sensor that is highly selective for the Zn2+ ions via internal charge transfer (ICT) mechanism in DMSO: H2O medium. The

We report the synthesis and characterization of heteroleptic terpyridyl complexes of d6 transition metal ions with Fe2+ and Ru2+ (1-3). Furthermore, we study the effect of substitution of either an electron donating group (-NH2) or electron withdrawing group (-NO2) at the 4′-position in the ligands by means of UV-vis, cyclic voltammetry, and differential pulse voltammetry measurements. The experimentally observed photophysical characteristics of the transition-metal based terpyridyl complexes are explained and supported by detailed quantum chemical calculations.

A series of mononuclear Mn(II)/terpyridine complexes were synthesized and characterized by elemental analysis, IR spectrum, and UV-vis spectrum. Catalytic activities of Mn(II)/4′-Ar-2,2′:6′,2″-terpyridine complexes were tested in the oxidation of cyclohexene or styrene in the presence of tert-butylhydroperoxide as oxidant. Significant catalytic effects of these complexes were observed in the oxidation of olefins, especially in the cyclo-oxidation of styrene.

A manganese complex covalently attached to a TiO2 electrode via a light-absorbing organic linker (L) was used in the photooxidation of 20,70-dihydrodichlorofluorescein (H2DCF). Significant and sustained photocurrent was observed upon

H-bonding mediated molecular recognition between substrate and ligand -COOH groups orients the substrate so that remote, catalyzed oxygenation of an alkyl C-H bond by a Mn-oxo active site can occur with very high (>98%) regio- and stereoselectivity. This paper identifies steric exclusion - exclusion of non H-bonded substrate molecules from the active site - as one requirement for high selectivity, along with the entropic advantage of intramolecularity. If unbound substrate molecules were able to reach the active site, they would react unselectively, degrading the observed selectivity. Both of the faces of the catalyst are blocked by two ligand molecules each with a -COOH group. The acid p-tBuC6H4COOH binds to the ligand -COOH recognition site but is not oxidized and merely blocks approach of the substrate therefore acting as an effective inhibitor for ibuprofen oxidation in both free acid and ibuprofen ester form. Dixon plots show that inhibition is competitive for the free acid ibuprofen substrate, no doubt because this substrate can compete with the inhibitor for binding to the recognition site. In contrast, inhibition is uncompetitive for the ibuprofen-ester substrate, consistent with this ester substrate no longer being able to bind to the recognition site. Inhibition can be reversed with MeCOOH, an acid that can competitively bind to the recognition site but, being sterically small, no longer blocks access to the active site.

A clean aqueous Kr?hnke reaction process has been accomplished via a one-pot procedure of 2-acetylpyridine with aromatic aldehyde and ammonium acetate under microwave irradiation or conventional heating conditions. This method is convenient, economic and environmental friendly.

A series of 4′-aryl-2,2′:6′,2″-terpyridines have been prepared by the one-pot reaction of 2-acetylpyridine with aromatic aldehydes in the presence of ammonium acetate under microwave irradiation. This method has the advantages of shorter route, easier workup, shorter reaction time, higher yield and more environmentally friendly conditions, compared to the conventional ones. Georg Thieme Verlag Stuttgart.

A facile one-pot synthesis of 4′-aryl-2,2′:6′,2″- terpyridines from aryl aldehydes and 2-acetylpyridine is presented. The synthesis of terpyridines incorporating sterically hindered aryl groups, such as the 9-anthryl group, can also be readily synthesized using this method.

Several 4′-aryl-substituted 2,2′:6′,2″-terpyridines (tpy-C6H4R) have been prepared by palladium-catalysed cross-coupling of 4′-bromoterpyridine or 4′-triflate-terpyridine (triflate = trifluoromethylsulfonyloxy) with aryl boronic acids or esters, RC6H4B(OR′)2 (R = H, m-NH2, p-CHO, -NO2, -CN, -NMe2, -NPh2). The new ligand 4′-mesityl-terpyridine (mesityl = 2,4,6-trimethylphenyl) was prepared in the same way. Similarly, 4′-bromophenylterpyridine (tpy-φ-Br) has been cross-coupled with aryl halides to generate several new biaryl-substituted terpyridines (tpy-φ-C6H4R where R = H, p-CN, NMe2, NPh2), together with two related compounds with pendent 3- or 4-pyridyl groups (tpy-φ-C6H4-py). For selected compounds, the alternative coupling strategy of reaction of a terpyridine-4-boronate or terpyridine-4-phenylboronate with the appropriate aryl halide has also been investigated (e.g. to prepare tpy-φ-C6H4NO2), but was generally found to be less satisfactory. All of the compounds are fluorescent in the UV region of the spectrum, the biaryl-substituted compounds being only slightly red-shifted compared to the monoaryl systems, but with the further red-shift that accompanies protonation being more significant for the former. Fluorescence lifetimes in solution are in the range 1-5 ns. The emission spectra of the aminobiphenyl-substituted compounds (tpy-φ-C6H4NR″2, where R″ = Me or Ph) display a large red-shift with increasing solvent polarity, suggesting the involvement of an intramolecular charge transfer state, as found previously for the two analogues omitting the phenyl ring (tpy-C6H4NR″2). In contrast to the latter, however, protonation or binding of a Lewis acidic metal ion to the aminobiphenyl compounds serves to quench almost completely their emission.

The synthesis and luminescence properties are reported for 20 different chelates composed of 2,2':6',2''-terpyridine as the energy-absorbing and donating group, Eu(III) and Tb(III) as the emitting ions, methylenenitrilo(acetic acids) as the stable chelate