125330-07-6

Upstream product

• 553-26-4 4,4'-bipyridine 
• 53344-73-3 4-(2-chloropyridin-4-yl)pyridine 
• 18511-71-2 4,4'-dibromo-2,2'-bipyridine 
• 1692-15-5 4-pyridylboronic acid 

Downstream Products

• 1169964-30-0 [Cu(C₁₂H₆N₂(C₆H₂(CH₃)3)2)(NC₅H₄CHNC₆H₄CH₃)]⁽¹⁺⁾*[PF₆]^(1-)=[Cu(C₁₂H₆N₂(C₆H₂(CH₃)3)2)(NC₅H₄CHNC₆H₄CH₃)][PF₆] 

Relevant academic research and scientific papers

Photoinduced electron transfer in supramolecular ruthenium-porphyrin assemblies

We present dynamic supramolecular systems composed of a Ru(ii) complex of the form of [Ru(dtBubpy)2(qpy)][PF6]2 (where dtBubpy is 4,4′-di-tert-butyl-2,2′-dipyridyl and qpy is 4,4′:2′,2′′:4′′,4′′′-quaterpyridine) and zinc t

Syntheses and properties of two-dimensional charged nonlinear optical chromophores incorporating redox-switchable cis-tetraammineruthenium(II) centers

In this article, we describe a series of new complex salts in which electron-donating cis-{RuII(NH3)4}2+ centers are connected to two electron-accepting N-methyl/aryl-pyridinium groups. These V-shaped complexes contain either monodentate 4,4′- bipyridyl-derived ligands or related chelates based on 2,2′:4,4″: 4′,4?-quaterpyridyl and have been characterized by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Molecular quadratic nonlinear optical (NLO) responses β have been determined by using hyper-Rayleigh scattering at 800 nm and also via Stark (electroabsorption) spectroscopic studies on the intense, visible d → π* metal-to-ligand charge-transfer bands. These experiments reveal that these dipolar pseudo-C2v chromophores exhibit two substantial components of the β tensor, βzzz and βzyy, with the difference between them being most marked for the nonchelated systems. Time-dependent density-functional theory and finite field calculations serve to further illuminate the electronic structures and associated linear and NLO properties of the new chromophoric salts.

Derivatives of Tris(2,2'-bipyridine)ruthenium(II) with Pendant Pyridyl or Phenol Ligands

Reaction of 2,2':4',4''-terpyridine or 4-(4-pyridyl)-2,2':4',4''-terpyridine with (bipy = 2,2'-bipyridine) and of 4-(p-methoxyphenyl)-2,2'-bipyridine with followed by demethylation of the anisole with BBr3, yields derivatives of Ru(bipy)3(2+) which contain externally directed pendant pyridyl or phenol groups capable of ligation to other metals.These complexes are proposed as 'building blocks' for photoactive polynuclear complexes containing the Ru(bipy)3(2+) chromophore.Methylation of the pendant pyridyl rings with methyl iodide generates electron-accepting groups covalently attached to the Ru(bipy)3(2+) core.

Syntheses and properties of complexes with bis(2,2′-bipyridyl) ruthenium(II) moieties coordinated to 4,4′:2′,2′′: 4′′,4′′′-quaterpyridinium ligands

Eleven new complexes of the form cis-[RuII(bpy) 2(LA)]4+ (bpy = 2,2′-bipyridyl; L A = a pyridinium-substituted bpy derivative) have been prepared and isolated as their PF6- salts

Redox properties of ground and electronically excited states: [Ru(bpy)2Qbpy]2+ monolayers

Dense monolayers of [Ru(bpy)2Qbpy]2+, where bpy is 2,2′-bipyridyl and Qbpy is 2,2′:4,4″:4′4″-quarterpyridyl, have been formed by spontaneous adsorption onto clean platinum microelectrodes. Cyclic voltammetry of these monolayers is nearly ideal, and five redox states are accessible over the potential range from +1.3 to -2.0 V. Chronoamperometry conducted on a microsecond time scale has been used to measure the heterogeneous electron-transfer rate constant, k, for both metal- and ligand-based redox reactions. Heterogeneous electron transfer is characterized by a single unimolecular rate constant (k/s-1). Standard heterogeneous electron-transfer rate constants, k°, have been evaluated by extrapolating Tafel plots of In k vs overpotential, η, to zero driving force to yield values of (5.1 ± 0.3) × 105 s-1, (3.0 ± 0.1) × 106 s-1, and (3.4 ± 0.2) × 106 s-1 for k°3+/2+, k°2+/1+, and k°1+/0, respectively. Temperature-resolved measurements of k reveal that the electrochemical activation enthalpy, ΔH?, decreases from 12.1 ± 1.7 kJ mol-1 for the 3+/2+ reaction to 7.5 ± 0.8 kJ mol-1 for the 2+/1+ process. Probing the temperature dependence of the formal potential gives the reaction entropy, ΔSrc°. Significantly, the free energy of activation is constant at 6.9 ± 0.6 kJ mol-1 for all three redox couples investigated. The electronic transmission coefficient, Kel, describing the probability of electron transfer once the transition state has been reached, is considerably less than unity for all three redox processes. Following photoexitation using a laser pulse at 355 nm, emission is observed from the monolayers with an excited-state lifetime (6.2 μs) that exceeds that of the complex in solution (1.4 μs). It appears that weak electronic coupling between the adsorbates and the electrode means that the excited states are not completely deactivated by radiationless energy transfer to the metal. For the first time, we have used voltammetry conducted at megavolt per second scan rates to directly probe the redox potentials and electron-transfer characteristics of electronically excited species.

Synthesis of highly charged ruthenium(II)-quaterpyridinium complexes: A bottom-up approach to monodisperse nanostructures

Tris-homoleptic ruthenium(II)-quaterpyridine and -quaterpyridinium complexes, possessing geometric dimensions in the nanoscale, have been synthesized. The diameters range from 1.82 to 4.55 nm according to molecular modeling. The new complexes are highly charged (either +8 or +14) and luminescent and represent examples for the 'bottom-up' approach to monodisperse nanostructures. Georg Thieme Verlag Stuttgart.

An iridium(III)-palladium(II) metal-organic cage for efficient mitochondria-targeted photodynamic therapy

An Ir8Pd4-heteronuclear metal-organic cage (MOC-51) was assembled from bipodal metalloligand [Ir(ppy)2(qpy)(BF4)] (qpy = 4,4′:2′,2″:4″,4?-quaterpyridine; ppy = 2-phenylpridine) with Pd(II) salt. The cubic barrel shaped MOC shows one-photon and two-photon excited deep-red emission, as well as large singlet oxygen quantum yields under visible light irradiation, therefore exhibiting great potentials in organelles-targeted cell imaging and photodynamic therapy (PDT). Compared with the Ir(III) metalloligand, the Ir8Pd4-MOC showed less dark toxicity and higher mitochondria-targeting efficiency. The localization in mitochondria overcomes the limitation of short lifetime and diffusion distance of ROS in cell, thus improved PDT effect can be obtained in low light dose usage of the MOC. This study presents the first case of Ir-based metal-organic cages for bio-applications in successful integration of imaging diagnosis and photodynamic therapy

2,2':4,4'':4',4'''-Quaterpyridyl: A Building Block for the Preparation of Novel Redox Reagents. 1. Preparation and Quaternization

An efficient preparation of 2,2':4,4'':4',4'''-quaterpyridyl (qpy) from 4,4'-bipyridine is described, using palladium on charcoal.Conditions are described for the selective methylation of the nitrogen atoms present.This has allowed the preparation of mono- and dimethylquaternary salts that retain an α-diimine site for complexation to a metal.These quarternary salts can be used to prepare complexes in which metal ions are coordinated to viologen-type ligands.Electrochemical and spectroscopic measurements of the diquarternary salt derived from qpy suggest that it behaves as two separate or weakly interacting monoquat moieties.

Phosphorescent soft salt for ratiometric and lifetime imaging of intracellular pH variations

In contrast to traditional short-lived fluorescent probes, long-lived phosphorescent probes based on transition-metal complexes can effectively eliminate unwanted background interference by using time-resolved luminescence imaging techniques, such as photoluminescence lifetime imaging microscopy. Hence, phosphorescent probes have become one of the most attractive candidates for investigating biological events in living systems. However, most of them are based on single emission intensity changes, which might be affected by a variety of intracellular environmental factors. Ratiometric measurement allows simultaneous recording of two separated wavelengths instead of measuring mere intensity changes and thus offers built-in correction for environmental effects. Herein, for the first time, a soft salt based phosphorescent probe has been developed for ratiometric and lifetime imaging of intracellular pH variations in real time. Specifically, a pH sensitive cationic complex (C1) and a pH insensitive anionic complex (A1) are directly connected through electrostatic interaction to form a soft salt based probe (S1), which exhibits a ratiometric phosphorescent response to pH with two well-resolved emission peaks separated by about 150 nm (from 475 to 625 nm). This novel probe was then successfully applied for ratiometric and lifetime imaging of intracellular pH variations. Moreover, quantitative measurements of intracellular pH fluctuations caused by oxidative stress have been performed for S1 based on the pH-dependent calibration curve.

Exploring the self-assembly and energy transfer of dynamic supramolecular iridium-porphyrin systems

We present the first examples of dynamic supramolecular systems composed of cyclometalated Ir(iii) complexes of the form of [Ir(C^N)2(N^N)]PF6 (where C^N is mesppy = 2-phenyl-4-mesitylpyridinato and dFmesppy = 2-(4,6-difluorophenyl)-