Photophysical Properties of 4′-(p-aminophenyl)-2,2′:6′,2′′-terpyridine

Spectral and photophysical investigations of 4′-(p-aminophenyl)-2,2′:6′,2′′-terpyridine (APT) have been performed in various solvents with different polarity and hydrogen-bonding ability.The emission spectra of APT are found to exhibit dual fluorescence in polar solvents, which attributes to the local excited and intramolecular charge transfer states, respectively. The two-state model is proven out for APT in polar solvent by the time-correlated single photon counting emission decay measurement. Interestingly, the linear relationships of different emission maxima and solvent polarity parameter are found for APT in protic and aprotic solvents, because of the hydrogen bond formation between APT and alcohols at the amino nitrogen N25. Furthermore, the effects of the complexation of the metal ion with tpy group of APT and the hydrogen bond formation between APT with methanol at the terpyridinenitrogen N4—N8—N14 are also presented. The appearance of new long-wave absorption and fluorescence bands indicates that a new ground state of the complexes is formed.     

Selective formation of thecis isomer of the nitridotechnetium(V) complex with 2,2′:6′,2″-terpyridine

The reaction of [TcNCl₂(PPh₃)₂] with 2,2′:6′,2″-terpyridine producedcis-[TcNCl₂(terpy)] selectively. The resulting complexes were characterized by¹H NMR and IR spectroscopy. The geometries of thecis andtrans isomers were estimated by theoretical calculations following a density functional method. Thecis isomer is likely more stable than thetrans one with respect to thetrans influence of the nitrido ligand. Furthermore, the behavior of nitridotechnetium complexes in polar solvents was compared to Os-analogues.     

Synthesis of a new 2,2′：6′,2″-terpyridine derivative and its coordination property

A novel compound, （E）-4′-（4-（but-1-en-3-ynyl）phenyl）-2,2′：6′,2″-terpyridine 1 was synthesized from 4′-（4-bromomethylphenyl）-2,2P：6P,2PP-terpyridine phosphonium salt 2 and propargylaldehyde via Wittig reaction, and characterized by EI-MS and ^1H NMR as well as elemental analysis. The spectral changes of the compound in the presence of transition metal ions, such as Cu（I） or Zn（ID, are investigated.     

Crystal structure of a hydroxo-bridged dimeric uranyl complex with a 2,2′:6′,2″-terpyridine ligand

A new dimeric compound [{UO₂(μ-OH)(terpy)}₂](ClO₄)₂·0.67CH₃CN, containing an uranyl cation and a tridentate 2,2′:6′,2″-terpyridine (terpy) ligand, is synthesized from an acetonitrile solution of uranyl perchlorate and terpy. The crystal structure of the compound is determined by single crystal X-ray diffraction. The crystal structure shows the formation of symmetric and asymmetric cationic hydroxo-bridged uranyl dimers. The uranium atoms adopt a distorted pentagonal bipyramidal configuration with a UO₄N₃ coordination environment formed by two uranyl O atoms, three N atoms from the terpy ligand, and two O atoms from the hydroxide anions.     

Syntheses and characterization of two 1D Cu(II) coordination polymers with 2,2′:6′,2″-terpyridine ligand

The solution reactions of CuCl₂ with 2,2′:6′,2″-terpyridine (Terpy) and dicarboxylic acid (glutaric acid or suberic acid) afforded two 1D coordination polymers [Cu(Terpy)(C₅H₆O₄)] _n (I) and [Cu(Terpy)(C₈H₁₂O₄)] · 3H₂O (II) and their structures were characterized by IR, TG-DTA, and single-crystal X-ray diffraction. Crystallographic data for I: C₂₀H₁₆CuN₃O₄, M _r = 425.90, monoclinic, space group C2/c, a = 10.335(2), b = 21.193(4), c = 8.580(2) Å, β = 111.99(3)°, V = 1742.5(6) ų, Z = 4, ρ _c = 1.623 g/cm³, F(000) = 872, R = 0.0304 and wR = 0.0915; and those for II: C₂₃H₂₉CuN₃O₇, M _r = 523.03, triclinic, space group P \(\bar 1\), a = 8.362(2), b = 10.605(2), c = 14.617(3) Å, α = 73.26(3)°, β = 86.23(3)°, γ = 69.45(3)°, V = 1161.3(4) ų, Z = 2, ρ _c = 1.496 g/cm³, F(000) = 546, R = 0.0636 and wR = 0.1106. X-ray diffracion studies reveal that both complexes I and II feature 1D chain. The 1D polymer chains are connected by π-π-stacking interactions to generate 2D supramolecular layers.     

Kinetics and mechanism of oxidation of bis(2,2′,6′,2″-terpyridine) iron(II) by manganese(IV)

A study has been made on the oxidation of bis(2,2,6, 2-terpyridine)-iron(II), Fe(tpy) ₂ ²⁺ by manganese (IV) using stopped-flow spectrophotometry in H₂SO₄–H₃PO₄ mixtures. The reaction is first order in each the substrate and the oxidant. The rate of the reaction increases with hydrogen ion concentration. A plausible mechanism is proposed considering the protonated forms of manganese(IV) as reactive oxidizing species. The reaction obeys the rate law

二-2,2′:6′,2″-三联吡啶-4′-(4-苯甲酰)-乙二胺的合成

二、三联吡啶作为螯合配体可以和过渡金属离子生成高度稳定的配合物,并具有有趣的物理性质。因此在过去的几十年里,二、三联吡啶金属配合物受到广泛而深入的研究。文章在前人的研究基础上获得了含官能化双(三联吡啶)单元结构的二-2,2′:6′,2″-三联吡啶-4′-(4-苯甲酰)-乙二胺配体,可以作为非共价聚合物的很有效的构建模块,合成有趣的金属超分子聚合物。     

4′-(2-Methylphenyl)-2,2′:6′,2″-terpyridine: coordination chemistry with Ni(II), Cu(II), Zn(II) and Ag(I)

The synthesis of 4′-(2-methylphenyl)-2,2′:6′,2″-terpyridine (L) has been improved. The coordination chemistry of the ligand was explored using Ni(II), Cu(II), Zn(II), and Ag(I) ions. X-ray crystallography, elemental analysis, NMR, and mass spectrometry were used to characterize the 13 new compounds that have been synthesized. Under different reaction conditions, Ni(II), Cu(II), and Zn(II) produced discrete complexes, sometimes containing more than one metal ion, while Ag(I) furnished a polymeric spiral complex in which the central pyridine nitrogen of each terpyridine ligand bridges two Ag(I) ions. Crystallographically characterized complexes are [Ni(L)₂]Cl₂, [Ni₂Cl₄(L)₂], [Ni(L)(OH₂)₃]Cl₂, [Ni(L)₂]Br₂, [Cu(L)(OH₂)(OSO₃)], [Cu₃Cl₆(L)₂], [Cu(L)(OH)(OH₂)₂]PF₆, [Cu(L)₂](OTf)₂, [Cu(L)(OAc)₂], [Zn(L)(OAc)₂], [Zn(L)Cl₂], [Zn(L)₂](NO₃)₂, [{Ag₂(μ-L)₂(μ-NO₃)}_n](NO₃)_n.     

[Bis(trispivalatodimolybdenum (II))-μ-bis(4′-carboxylato-2,2′:6′,2″-terpyridine) ruthenium (II)] (2+) Tetrafluoroborate: Photophysical Studies

The photophysical properties of the title compound have been studied by fs and ns transient absorption spectroscopy. The electronic absorption spectrum consists of three principle absorptions assigned to terpy ¹LLCT at ~300 nm, ruthenium (II) t_2g⁶ to terpy ¹MLCT at ~470 nm and Mo₂ δ to terpycarboxylate at ~670 nm. The compound shows weak room temperature emission in THF solution at ~1,100 nm when excited into each of the aforementioned bands. This emission is assigned to the T₁ state, ³MMδδ*. Transient absorption spectroscopy indicates a lifetime for T₁ of 9.6 μs. This paper is dedicated to Prof. C. N. R. Rao.     

Cadmium(II) complexes of 4′-tolyl-2,2′:6′,2′′-terpyridine: synthesis,structures, and antibacterial activities

A straightforward synthetic method has been developed to prepare cadmium(II) complexes of 4′-tolyl-2,2′:6′,2″-terpyridine (ttpy) in good yields. These complexes are formulated as {[Cd(ttpy)(NO₃)₂][Cd₂(ttpy)₂(NO₃)₄]} (1), [Cd₂(ttpy)₂(N₃)₄]0.5CH₃OH?·?0.125H₂O (2), and {[Cd(ttpy)(SCN)(CH₃COO)][Cd(ttpy)(SCN)₂]₂} (3). Intermolecular, intramolecular, hydrogen bonding and π–π stacking interactions were observed in the complexes, and are responsible for the arrangement of complexes in the crystal packing and play essential roles in forming different frameworks of 1–3. The antibacterial activities of the synthesized complexes were tested against three gram positive bacteria and three gram negative bacteria.     

Synthesis,characterization and in vitro antitumor behavior of a vanadium(V) complex with 4′-(3-methoxyphenyl)-2,2′:6′2″-terpyridine

A dioxovanadium(V) complex, [VO₂(moptpy)](ClO₄) (1, moptpy = 4′-(3-methoxyphenyl)2,2′:6′2″-terpyridine), was synthesized and characterized by elemental analysis, ESI-MS, UV–vis, IR, and ¹H, ¹³C, and ⁵¹V NMR. The cytotoxicity in vitro of 1 was evaluated against cancer cell lines HepG-2 (hepatocellular carcinoma), SGC-7901 (gastric carcinoma), SiHa (cervical cancer), BEL-7402 (hepatocellular), and rat PC-12 (pheochromocytoma) by the MTT method. The results demonstrated that 1 exhibits superior anticancer activity in vitro with much lower values of 50% inhibitive concentration (IC₅₀) against the selected cell lines than cisplatin, and 1 shows the highest cytotoxic activity toward SGC-7901 cells (IC₅₀ = 1.3 ± 0.1 μM) among the selected cell lines. A series of cellular morphological and staining experiments were carried out, and the results indicated that 1 can effectively induce apoptosis of SGC-7901 cells through a ROS-mediated mitochondrial dysfunction pathway. In addition, cellular incorporation and cell cycle analysis were also performed, and it was concluded from the experimental observations that 1 can efficiently enter into the cell nuclei, and the complex inhibits cell growth in SGC-7901 cell at G0/G1 phase.     

2,2′:6′,2″-联三吡啶配体的合成

近年来,2,2′:6′,2″-联三吡啶作为典型的三齿有机杂环配体在超分子化学与材料化学领域得到广泛应用。通过取代基团对配体的结构修饰或改变金属离子的类型可以调控联三吡啶金属络合物的光物理和电化学性能,从而得到多种不同用途的功能化材料及超分子组装体。本文对单核联三吡啶配体近年来发展的典型合成方法加以阐述,并简单介绍联三吡啶配体在超分子化学中的应用。     

Spectroscopic, thermal and structural studies of a new mercury(II) complex of 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine (pyterpy) ligand, [Hg (hpyterpy)(SCN)2]2(MeSO4)2

A new mercury(II) complex [Hg(Hpyterpy)(SCN)₂]₂(MeSO₄)₂ was prepared from the reaction of 4′-(4-pyridyl)-2,2′:6′,2″- terpyridine (pyterpy), as a polypyridyl ligand, with mercury(II) thiocyanate. The compound was characterized by elemental analysis, IR, ¹H NMR and ¹³C NMR spectroscopy and its structure was determined by X-ray single-crystal diffraction. The thermal stability of compound was studied by thermogravimetric (TG) and differential thermal analyses (DTA).     

Synthesis,vibrational spectra,and structure of 4′-(4″-benzo-15-crown-5)oxy-2,2′:6′,2″-terpyridine (L) and its transition metal complexes. Extraction and ion-selective properties of L

Complexes of Co(II), Ni(II), Zn(II), and Cu(II) perchlorates and hexafluorophosphates with 4′-(4″-benzo-15-crown-5)oxy-2,2′:6′,2″-terpyridine (L) [M(L)₂](ClO₄)₂ · 3H₂O and [M(L)₂](PF₆)₂ · 2H₂O were synthesized. The spectral criteria of ligand coordination through the terpyridine nitrogen atoms were established. An assumption concerning the benzo-15-crown-5 conformation in the ligand molecule in the synthesized complexes was made. The extraction and ion-selective properties of L were studied.     

Understanding the role of flexible 4′-functionalized polyethylene glycoxy chains on the behavior of platinum(II) (4′-(ethylene glycoxy)-2,2′:6′,2′′-terpyridine: a kinetic and a mechanistic study

The ligand substitution kinetics of 4′-functionalized mononuclear Pt(II) (4′-(ethylene glycoxy)-2,2′:6′,2′′-terpyridine complexes, [Pt(nY-tpy)Cl)Cl] (where Y = ethylene glycoxy, n = number of ethylene, glycoxy units = 1, 2, 3, and 4, and tpy = 2,2′:6′,2′′-terpyridine), with thiourea, 1,3-dimethyl-2-thiourea, 1,1,3,3-tetramethyl-2-thiourea, and iodide were investigated under pseudo-first-order conditions as a function of concentration and temperature by conventional stopped-flow technique. The observed first-order rate constants followed the simple rate law k_obs = k₂[Nu]. The data obtained show that the ethylene glycoxy pendant, trans to the leaving group, acts as a σ-donor into the terpyridine ligand and is effective only up to n = 1, beyond which the substitution reactivity of the complexes are controlled by the steric influence of the appended ethylene glycoxy pendant units, which decreases with increase in the number of ethylene glycoxy units. The activation parameters obtained support an associative mechanism, where bond formation in the transition state is favored. The observed reactivity trends were supported by density functional theory calculations.     

The effect of solvents and organic acids on the p-doping behaviors of poly(3′,4′-Ethylenedioxy-2,2′:5′,2″-terthiophene)

Poly(3??,4??-Ethylenedioxy-2,2??:5??,2??-terthiophene) was synthesized by chemical oxidative polymerization of 3??,4??-Ethylenedioxy-2,2??:5??,2??-terthiophene using FeCl₃ as an oxidant. The resulting polymer was characterized by FTIR and ¹H NMR. p-doping behaviors of substituted polyterthiophene with different organic sulfonic acids (methanesulfonic acid, p-toluene sulfonic acid, and ??-naphthalene sulfonic acid) in different solvents (CH₃CN, CHCl₃, THF and DMF) were studied by UV-VIS spectroscopy. The results from structural characterizations showed that the ??,????-bonding predominates in polyterthiophene. The spectroscopic changes in UV-VIS showed that ??-naphthalene sulfonic acid was an efficient doping acid for polymer while varying the solvents. Meanwhile, CH₃CN showed a high efficiency for p-doping of polyterthiophene while varying the doping acids.     

An Efficient and Easy Synthesis of Tetrasubstituted 2,2′:6′,2″-Terpyridines

An efficient synthesis of 4,4″-dinitro-5,5″-dimethyl-2,2′:6′,2″-terpyridine was accomplished. The crystal structures of three different 2,2':6’,2″-terpyridines were determined by x-ray analysis.     

6′,6″-二吡啶基-2,2′:4′,4″:2″,2′″-四联吡啶稀土配合物的合成、表征及荧光性质研究(英文)

0 IntroductionMetallosupramolecular oligomers and polymerscan result from the interaction of metal ions with ap-propriate multidentate ligands designed for multinucle-ar binding[1,2], and there are considerable interests in thedesign of species containing known numbers of metalions in defined spatial arrangements. The electronic andphotophysical properties of oligopyridine complexes oftransition-metal ions make their incorporation particu-larlyattractive and the possibilityofinter-metallic ele…     

A kinetic and mechanistic study of dinuclear Pt(II) 2,2′:6′,2″-terpyridine compounds bridged with polyethyleneglycol ether flexible linkers

A series of dinuclear Pt(II) complexes bridged with polyethyleneglycol ether of the type [ClPt(tpy)O(CH₂CH₂O)_n(tpy)PtCl]Cl₂ where n = 1 (Ptdteg), 2 (Ptdtdeg), 3 (Ptdtteg), 4 (Ptdttteg), and linker-free complex, (Ptdt) (where tpy = 2,2′:6′,2″-terpyridine), were synthesized and characterized to investigate the role of bridging polyethyleneglycol ether linker on the substitution reactivity of dinuclear Pt(II) complexes. Substitution reactions were studied using thiourea nucleophiles, viz. thiourea (TU), 1,3-dimethyl-2-thiourea (DMTU), 1,1,3,3-tetramethyl-2-thiourea (TMTU) under pseudo-first-order conditions as a function of concentration and temperature by conventional stopped-flow reaction analyzer. The reactions gave single exponential fits following the rate law k_obs = k₂[Nu]. Introduction of polyethyleneglycol ether linker decreases the electrophilicity of the platinum center and the whole complex. The results obtained indicate that the rate of substitution is controlled by both electronic and steric hindrance which increases with the length of the linker. Experimental results are supported by density functional theory calculations and structures obtained at B3LYP/LANL2DZ level. The order of the reactivity of the nucleophiles is TU > DMTU > TMTU. The magnitude and the size of the enthalpy of activation and entropy of activation support an associative mode of mechanism, where bond formation in the transition state is favored.     

Synthesis,molecular structure and electrochemistry of cobalt(II) complexes of 2,2′: 6′,2′′-terpyridine macrocycles

The macrocycle L, prepared by template condensation of bis-6,6′′-(α-methylhidrazino)-4′-phenyl-2,2′:6′′,2′-terpyridine with glyoxal, forms a stable crystalline complex of cobalt(II) [Co(L)(H₂O)₂][PF₆]₂ which has been used as a starting material to prepare, for electrochemical studies, a series of seven coordinate cobalt(II) complexes [Co(L)X₂][PF₆]₂ (X=pyridine, 4-cianopyridine, 4-aminopyridine, 4-dimethylaminopyridine, pirazine, imidazole, 1-methylimidazole, 2-methylimidazole, and trimethylphosphite). Cyclic voltammetry of the aquo complex in DMSO show one reversible reduction wave at −1.35 V versus Ag ∣ AgBF₄ reference electrode and controlled potential electrolysis in the presence of trimethylphosphite affords a diamagnetic species which has been assigned as a mononuclear d⁸ Co(I) species. The crystal and molecular structure of [Co(L)(imidazole)₂][PF₆]₂·Me₂CO shows the metal to be in a pentagonal-bipyramidal N₇ environment.