- Terpyridine derivatives as turn-on fluorescence chemosensors for the selective and sensitive detection of Zn2+ ions in solution and in live cells
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A terpyridine based compound L1 was designed and synthesized as an off-on chemosensor for the detection of Zn2+. Chemosensor L1 showed excellent selectivity and sensitivity toward Zn2+ by exhibiting a large fluorescence enhancement (～51-fold) at 370 nm whereas other competitive metal ions did not show any noticeable change in the emission spectra of chemosensor L1. The chemosensor (L1) was shown to detect Zn2+ ions down to 9.76 μM at pH 7.4. However, chemosensor L1 binds Zn2+ in a 1:2 ratio (receptor:metal) with an association constant of 1.85 × 104 (R2 = 0.993) and this 1:2 stoichiometric fashion is established on the basis of a Job plot and mass spectroscopy. DFT/TD-DFT calculations were carried out to understand the binding nature, coordination features and electronic properties of L1 and the L1-2Zn2+ complex. In addition, this turn-on fluorescence probe was effectively used to image intracellular Zn2+ ions in cultured MDA-MB-468 cells.
- Mandal, Tripti,Hossain, Anowar,Dhara, Anamika,Al Masum, Abdulla,Konar, Saugata,Manna, Saikat Kumar,Seth, Saikat Kumar,Pathak, Sudipta,Mukhopadhyay, Subrata
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- Self-Assembled Pd(II) Barrels as Containers for Transient Merocyanine Form and Reverse Thermochromism of Spiropyran
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Self-assembly of a cis-blocked Pd(II) 90° ditopic acceptor [cis-(tmeda)Pd(NO3)2] (M) with a tetradentate donor L1 [benzene-1,4-di(4-terpyridine)] in 2:1 molar ratio yielded two isometric molecular barrels MB1 and MB3 in DMSO [tmeda = N,N,N′N′-tetramethylethane-1,2-diamine]. Exclusive formation of the symmetrical tetrafacial barrel (MB1) was achieved when the self-assembly was performed in aqueous medium. The presence of a large confined cavity makes MB1 a potential molecular container. Spiropyran (SP) compounds exist in stable closed spiro form in visible light and convert to transient open merocyanine (MC) form upon irradiation with UV-light or upon strong heating. The transient MC form readily converts to the stable closed SP form in visible light. MB1 has been employed as a safe container to store the planar and unstable merocyanine isomers (MC1/2) of different spiropyran molecules (SP1/2) [SP1/2 = 6-bromo-spiropyran and 6-nitrospiropyran] for several days. The transient MC forms (MC1 and MC2) were found to be stable inside the molecular container MB1 under visible light and even in the presence of different stimuli such as heat and UV light for a long time. Such stabilization of MC forms inside the confined cavity of MB1 is noteworthy. This phenomenon was generalized by utilizing a carbazole-based molecular barrel (MB2) as a host, which also showed a similar stabilization of transient MC form in visible light at room temperature. Moreover, reverse thermochromism was observed as a result of heating of the MC1 ? MB2 complex, which de-encapsulates the guest in the form of SP1 to give a colorless solution. Moreover, both the host molecules (MB1, MB2) were capable of stabilizing transient MC2 even in the solid state. Such stabilization of transient MC forms in the solid state and transformation of SP forms to MC forms in the solid state in the presence of molecular barrel are remarkable, and these properties have been employed in developing a magic ink.
- Howlader, Prodip,Mondal, Bijnaneswar,Purba, Prioti Choudhury,Zangrando, Ennio,Mukherjee, Partha Sarathi
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- Spectroscopic and antimicrobial activity of photoactivatable tricarbonyl Mn(I) terpyridine compounds
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The photoinduced fac-[MnBr(CO)3(L–k2N1,N2)] (L = 4′-(2-pyridyl)-2,2′:6′,2′'-terpyridine (LPy) (1) and 4′-(4-phenyl morpholine)-2,2′:6′,2′'-terpyridine (Lmorph) (2)) and fac-[Mn2B
- Mansour, Ahmed M.,Radacki, Krzysztof
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- New solid-state Eu(III)-containing metallo-supramolecular polymers: Morphology control and optical wave-guiding properties
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Herein, we report the solution phase self-assembly between Eu(iii) and a rigid ditopic tridentate terpyridine ligand which results in the formation of supramolecular metallo-networks in the solid state. Depending on the ligand to metal ratio used for the initial self-assembly process, the morphology of these materials can be altered from one-dimensional micron-sized fibres to a three-dimensional coordination network. The terpyridine-based ditopic ligand can act as an efficient sensitizer for Eu(iii) emission whereby the emission lifetimes and ligand triplet state energies of the metallo-polymers strongly depend on the ligand to metal ratio. The obtained micron-sized fibres can act as an efficient optical wave-guide for Eu(iii) emission.
- Duerrbeck, Andre,Gorelik, Sergey,Hobley, Jonathan,Yong, Anna Marie,Subramanian, Gomathy Sandhya,Hor, Andy,Long, Nicholas
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- Terpyridine Zn(II) azide compounds: Spectroscopic and DFT calculations
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Square-pyramidal Zn(II) azide complexes with the formula of [Znn(N3)2nL] (n = 1; L = 4′-(2-pyridyl)-2,2′:6′,2′'-terpyridine (LPy), 4′-(4-phenylmorpholine)-2,2′:6′,2′'-terpyridine (LMorph), and n = 2; L = 1,4-bis(2,2′:6′,2′'-terpyridin-4′-yl)benzene (LBPY)) were synthesized, and structurally characterized using different spectroscopic and analytical tools. Ground-state geometry optimization and harmonic vibrational analysis were carried out at two different levels of theory (B3LYP/LANL2DZ and CAM-B3LYP/def2-SVP) to gather insights into the local minimum structures. Natural bond orbital (NBO) analyses revealed that the electronic population of the 3d orbitals of Zn(II) ion is corresponding to the oxidation state of Zn(I), not Zn(II), in agreement with the ligand to metal charge transfer. Molecular electrostatic potential energy maps showed that the azido ligand may act as a nucleophile in the cycloaddition coupling with electron poor dipolar molecules. The electronic structure and transitions were investigated by executing time dependent density functional theory (TDDFT) calculations.
- Mansour, Ahmed M.
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- Wirelike dinuclear ruthenium(II)polyterpyridine complexes based on D–P–A architecture: Experimental and theoretical investigation
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To accomplish the goal of prolonged excited state, efficient for interfacial electron injection and low electron-hole recombination (LUMO?→?HOMO of complex) we have synthesized a heteroleptic complexes 1 and 2 based on D–P–A architecture (where P?=?Photosensitizer, A?=?Acceptor and D?=?Donor). The complexes 1 and 2 show the average excited state lifetimes (τavg) of 25?ns and 12.67?ns respectively compared to 0.25?ns for [Ru(tpy)2]2PF6. The τavg of such an order is sufficient for performing the interfacial electron transfer into the conduction band of TiO2 and redox chemistry of excited state. The electrochemical studies exhibit the oxidation potential (Eox) of 1.23?V and 1.27?V vs SCE with associated excited-state redox potentials (Eox*=?0.95?V and ?0.85?V and Ered*=1.0?V and 0.88?V for complexes 1 and 2 respectively) have evidence for stronger reductant and oxidant behaviour in 1MLCT excited state. Subsequent interfacial study with TiO2 nanocrystal is in good agreement with photo induced electron injection from LUMO of complex to conduction band (CB) of TiO2 as LUMO level (?3.22?eV and 3.16?eV for complexes 1 and 2 respectively) of complexes is above the CB of TiO2 (?3.65?eV). The experimental photophysical results of both the complexes are well supported by time dependent density functional theory.
- Singh, Pallavi,Rana, Prem Jyoti Singh,Kar, Prasenjit
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- Binuclear metal iridium complex as well as preparation method and application thereof
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The invention relates to the technical field of medicines, in particular to a binuclear metal iridium complex as well as a preparation method and application thereof. The binuclear cyclometallated iridium photosensitizer shown in the formula (I) is non-toxic to tumor cells under the dark condition, but has very strong growth inhibition ability to the tumor cells under the illumination condition, has important significance for researching high-efficiency and low-toxicity anti-tumor drugs, can be further used for preparing the anti-tumor drugs, and has a great application prospect.
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Paragraph 0032; 0035-0038
(2021/07/24)
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- A new strategy to design a graphene oxide supported palladium complex as a new heterogeneous nanocatalyst and application in carbon–carbon and carbon-heteroatom cross-coupling reactions
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The palladium nanoparticles were successfully stabilized with an average diameter of 6–7?nm through the coordination of palladium and terpyridine-based ligands grafted on graphene oxide surface. The graphene oxide supported palladium nanoparticles were thoroughly characterized and applied as an efficient heterogeneous catalyst in carbon–carbon (Suzuki-Miyaura, Mizoroki-Heck coupling reactions) and carbon–heteroatom (C-N and C-O) bond-forming reactions. The catalyst was simply recycled from the reaction mixture and was reused consecutive four times with small drop in catalytic activity.
- Bahrami, Kiumars,Targhan, Homa
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- A green and straightforward synthesis of 4′-substituted terpyridines
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A set of 4′-substituted 2,2′:6′,2″-terpyridines has been synthesized in a one-pot procedure under environmentally friendly reaction conditions using PEG and aqueous ammonia as solvents. This procedure features a short synthetic route, short reaction times, easy work-up, and good yields in comparison to conventional methods. The crystallographic data reveal the influence of the 4′-aryl substituent on the molecular structure and π-stacking behavior of the respective terpyridines. Georg Thieme Verlag Stuttgart.
- Winter, Andreas,Van Den Berg, Antje M. J.,Hoogenboom, Richard,Kickelbick, Guido,Schubert, Ulrich S.
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p. 2873 - 2878
(2008/02/05)
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- Linear multinuclear RuII photosensitizers
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Four ditopic bridging ligands, containing 2,2′:6′,2″- terpyridine and 2,6-dipyrazinylpyridine (dpp) metal-binding units attached through p- or m-phenylene linkages, have been incorporated into eight mono-, di- and trinuclear linear RuII complexes. These were characterized by UV/Vis spectroscopy and cyclic voltammetry, and by their ability to undergo light-induced electron transfers to methylviologen. The dpp-bearing complexes were more difficult to prepare but were superior sensitizers, a fact attributable to longer excited state lifetimes and an electrostatically favored reductive quenching pathway. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Vaduvescu, Simona,Potvin, Pierre G.
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p. 1763 - 1769
(2007/10/03)
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- Convenient synthesis of bis-bipyridines and bis-terpyridines bridged by phenyl and biphenyl tethers
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A simple three step preparation of phenyl bridged bis-2,2'-bipyridine and bis-2,2':6',2''-terpyridine from readily available reagents is described. The compounds have the potential to serve as rigid bridging ligands for the preparation of redox and photoactive supramolecular complexes of transition metals.
- Baba,Wang,Won Yong Kim,Strong,Schmehl
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p. 1029 - 1036
(2007/10/02)
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- Multinucleating 2,2':6',2''-Terpyridine Ligands as Building Blocks for the Assembly of Co-ordination Polymers and Oligomers
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The co-ordination properties of the tridentate ligand 2,2':6',2''-terpyridine (terpy) make it an ideal structural unit from which to assemble co-ordination oligomers and polymers with a linear connectivity about the metal centre.The dinucleating 'back-to-back' 2,2':6',2''-terpyridine ligands 6',6''-bis(2-pyridyl)-2,2':4',4'':2'',2'''-quaterpyridine L1 and 1,4-bis(2,2':6',2''-terpyridin-4'-yl)benzene L2 give rise to a linear connectivity at the ligand, whereas 1,3,5-tris(2,2':6',2''-terpyridin-4'-yl)benzene L3 is a trinucleating species which can give rise to arrays with a connectivity of three at the ligand.The coordination oligomers (4+) (L = L1 or L2) and 3L3>(6+) (X-terpy = 4'-substituted 2,2':6',2''-terpyridine) have been prepared and characterised for a variety of electron-donating and -withdrawing substituent groups X.
- Constable, Edwin C.,Thompson, Alexander M. W. Cargill
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p. 3467 - 3476
(2007/10/02)
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