15862-19-8Relevant articles and documents
Terpyridine-based heteroditopic ligand for RuIILn3III metallostar architectures (Ln = Gd, Eu, Nd, Yb) with MRI/optical or dual-optical responses
Boulay, Alexandre,Deraeve, Cline,Vander Elst, Luce,Leygue, Nadine,Maury, Olivier,Laurent, Sophie,Muller, Robert N.,Mestre-Voegtl, Batrice,Picard, Claude
, p. 1414 - 1425 (2015)
A new ditopic ligand (L) based on a 2,2′:5′,4″-terpyridine unit substituted in the 2″,6″ positions with iminodiacetate arms has been designed and synthesized for the construction of RuIIL3Ln3III supramolecular architectures. The two components of this system, a 2,2′-bipyridine unit for RuII coordination and a pyridine-bis(iminodiacetate) core for LnIII coordination, are tightly connected via a covalent Carom(py)-Carom(py) bond. The paramagnetic and photophysical properties of the corresponding tetrametallic RuIIL3Gd3III complex have been evaluated, highlighting the potential of this metallostar structure to act as a bimodal MRI/optical imaging agent. Variable-temperature 17O NMR and proton nuclear magnetic relaxation dispersion (NMRD) measurements showed that this complex exhibits (i) a remarkable relaxivity per metallostar molecule, particularly at clinical and high magnetic fields (r1310K = 51.0 and 36.0 mM-1 s-1 at 20 and 300 MHz, respectively) and (ii) a near-optimal residence lifetime of GdIII coordinated water molecule (τM310K = 77.5 ns). This is the result of the presence of two inner-sphere water molecules in the GdIII components of the metallostar and a slow tumbling rate of the molecule (τR310K = 252 ps). Upon excitation in the visible domain (λexc = 472 nm), the RuII component of the complex exhibits a bright-red luminescence centered at 660 nm with a quantum yield of 2.6% in aqueous solutions at pH 7.4. Moreover, this RuIIL3Gd3III assembly is also characterized by a high kinetic inertness in biological media (PBS and human serum solutions) and a high photostability (photobleaching). Finally, preliminary photophysical studies on RuL3Nd3 and RuL3Yb3 assemblies revealed that the RuII center acts as an effective sensitizer for LnIII-based luminescence in the near-IR region. The NdIII species was found to be the most effective at quenching the 3MLCT luminescence of the Ru center.
Fabrication of high-performance and low-hysteresis lead halide perovskite solar cells by utilizing a versatile alcohol-soluble bispyridinium salt as an efficient cathode modifier
Chen, Guiting,Zhang, Fan,Liu, Meiyue,Song, Jun,Lian, Jiarong,Zeng, Pengju,Yip, Hin-Lap,Yang, Wei,Zhang, Bin,Cao, Yong
, p. 17943 - 17953 (2017)
A novel alcohol-soluble conjugated bispyridinium salt (FPyBr) is developed and used as a cathode modifier to improve the cathode interface of planar heterojunction perovskite solar cells (PHJ PVSCs). The excellent electron-withdrawing ability of bispyridinium rings endows FPyBr with a favorable energy level alignment with phenyl-C60-butyric acid methyl ester (PCBM) and the cathode (e.g., Al), which leads to an ideal ohmic contact and efficient electron transport and collection. The deep-lying highest occupied molecular orbital energy level of FPyBr can also effectively block hole carriers and thus decrease leakage current and hole-electron recombination at the cathode interface. In addition, FPyBr can n-dope PCBM through an anion-induced electron transfer process, which increases the electron mobility of PCBM drastically, thereby diminishing interfacial resistance and promoting electron transport. As a result, by incorporating an FPyBr cathode interlayer with ethanol solvent, high-performance and low-hysteresis PHJ PVSCs with a maximal power conversion efficiency (PCE) of 19.61% can be realized. In contrast, reference devices without any cathode interlayer display a distinctly worse performance, with a PCE of 16.97%. Therefore, this excellent cathode modifier provides a new opportunity to fabricate high performance multilayer PVSCs using lowerature solution processing without interfacial erosion/mixing.
Single-molecule white-light of tris-pyrazolonate-Dy3+ complexes
Liu, Jiaxiang,Shi, Qi,He, Yani,Fu, Guorui,Li, Wentao,Miao, Tiezheng,Lü, Xingqiang
, (2019)
Based on the self-assembly of the pyrazolone ligand HPMIP (1-phenyl-3-methyl-4-(isobutyryl)-5-pyrazolone), DyCl3·6H2O and/or the 5-Br-2,2′-bpy (5-bromo-2,2′-bipyridine), two tris-pyrazolonate-Dy3+-complexes [Dy(PMIP)3(H2O)2] (2) and [Dy(PMIP)3(5-Br-2,2′-bpy)] (5) characteristic of dual-emissive emissions toward single-molecule white-light are obtained, respectively, and in dependence on the effective suppression from the oscillator-induced quenching by the involved 5-Br-2,2′-bpy, the color-compensation of the residual ligands-based strong emission and the Dy3+-centered (4F9/2 → 6HJ/2 transitions) multiple emissions renders its Dy3+-complex 5 an efficient (Φem = 4.2%) single-molecule white-light.
Copper-Free One-Pot Sonogashira-Type Coupling for the Efficient Preparation of Symmetric Diarylalkyne Ligands for Metal-Organic Cages**
Lehr, Marc,Paschelke, Tobias,Bendt, Victoria,Petersen, André,Pietsch, Lorenz,Harders, Patrick,McConnell, Anna J.
, p. 2728 - 2735 (2021)
The often time-consuming and challenging multi-step synthesis of ligands for metal-organic cages is a limiting factor for the discovery and application of new cages. We report a highly efficient copper-free one-pot Sonogashira-type coupling for the preparation of symmetric diarylalkyne ligands on both a small and large scale; bipyridine- and benzimidazole-based ligands for the self-assembly of Co4L6 cages were synthesized in short reaction times and high isolated yields directly from aryl halide precursors. This one-pot method reduces the synthetic burden of ligand synthesis and will facilitate the preparation of ligands with additional functionality for applications of their corresponding cages.
Fullerene receptor based on calix[5]arene through metal-assisted self-assembly
Haino, Takeharu,Araki, Hiromi,Yamanaka, Yuko,Fukazawa, Yoshimasa
, p. 3203 - 3206 (2001)
A self-assembled fullerene receptor based on calix[5]arene has been developed. Silver cation complexation held together the two calix[5]arenes with bipyridine units providing a large enough cavity to take up C60 or C70. The formation of the supramolecular complex with C60 or C70 was established by using the electrospray mass spectrometry.
Enhancing Photocatalytic Hydrogen Generation: the Impact of the Peripheral Ligands in Ru/Pd and Ru/Pt Complexes
Das, Nivedita,Bindra, Gurmeet Singh,Paul, Avishek,Vos, Johannes G.,Schulz, Martin,Pryce, Mary T.
, p. 5330 - 5337 (2017)
The synthesis, photophysical properties and photocatalytic efficiency of a range of novel supramolecular assemblies of the type [Ru(dceb)2(μ-bisbpy)MCl2][PF6]2 and [Ru(bpy)2(μ-bisbpy)MCl2][PF6]2 (M=Pd or Pt, dceb=diethyl 2,2’-bipyridine-4,4’-dicarboxylate, bpy=2,2’-bipyridine and bisbpy=2,2’:5’,3’’:6’’,2’’’-quaterpyridine) are reported. Photocatalytic hydrogen generation was dependent on the nature of the peripheral ligand, on the catalytic centre and on the amount of water present in the photocatalytic mixture. The best catalytic conditions were obtained with the dceb peripheral ligand (turnover numbers up to 513 after 18 h). The experimental data and DFT calculations on both the bpy- and dceb-based compounds indicated that the peripheral dceb ligands participated in the photocatalytic process.
A Paramagnetic NMR Spectroscopy Toolbox for the Characterisation of Paramagnetic/Spin-Crossover Coordination Complexes and Metal–Organic Cages
Lehr, Marc,McConnell, Anna J.,N?ther, Christian,Paschelke, Tobias,S?nnichsen, Frank D.,Trumpf, Eicke,Vogt, Anna-Marlene
, p. 19344 - 19351 (2020)
The large paramagnetic shifts and short relaxation times resulting from the presence of a paramagnetic centre complicate NMR data acquisition and interpretation in solution. As a result, NMR analysis of paramagnetic complexes is limited in comparison to diamagnetic compounds and often relies on theoretical models. We report a toolbox of 1D (1H, proton-coupled 13C, selective 1H-decoupling 13C, steady-state NOE) and 2D (COSY, NOESY, HMQC) paramagnetic NMR methods that enables unprecedented structural characterisation and in some cases, provides more structural information than would be observable for a diamagnetic analogue. We demonstrate the toolbox's broad versatility for fields from coordination chemistry and spin-crossover complexes to supramolecular chemistry through the characterisation of CoII and high-spin FeII mononuclear complexes as well as a Co4L6 cage.
Carboxy derivatised Ir(iii) complexes: synthesis, electrochemistry, photophysical properties and photocatalytic hydrogen generation
Paul, Avishek,Das, Nivedita,Halpin, Yvonne,Vos, Johannes G.,Pryce, Mary T.
, p. 10423 - 10430 (2015)
In this contribution the synthesis and characterisation of a series of novel mixed ligand iridium(iii) complexes, functionalised with a carboxy ester or phosphonate groups are reported. These groupings are introduced on the 4-position of either the phenyl pyridine or the 2,2′-bipyridyl ligands. A low temperature high yield synthesis for the precursor [Ir(ppy-COOEt)2(μ-Cl)]2 was developed. The photophysical and electrochemical properties of these compounds are also described, together with their behaviour as photosensitisers for the generation of hydrogen from water.
Electrochemiluminescent dinuclear Ru(II) complexes assembled with 1,1′-(1,2-ethynediyl)- or dimethlyene-bridged bis(bipyridine) ligands: Synthesis and photophysical and electrochemical properties
Kim, Minki,Kang, Chang Hoon,Hong, Subong,Lee, Won-Yong,Kim, Byeong Hyo
, p. 145 - 150 (2013)
1,2-Di(2,2′-bipyridin-5-yl)ethane (BL1) and 1,2-di(2,2′- bipyridin-5-yl)ethyne (BL2) were synthesized as new bridging ligands and coordinated to (RuL2(acetone)2)(PF6) 2 for the preparation of various [Ru(L)2(BL)Ru(L) 2](PF6)4-type dinuclear ruthenium complexes (where BL = BL1, BL2 and L = bpy, o-phen, DTDP). The electrochemical redox potentials, spectroscopic properties, and relative electrochemiluminescence intensity of BL1 and BL2 were characterized and compared to those of well-known tris(1,10-phenanthroline)rutheniun(II) [Ru(o-phen)3](PF 6)2] complex as a reference. Dinuclear Ru(II) complexes containing the conjugated bridging ligand (BL2) showed much more intense electrochemiluminescent responses than dinuclear Ru(II) complexes with the non-conjugated bridging ligand (BL1). Among the complexes with conjugated bridging ligands, [(DTDP)2Ru(bpy-CC-bpy)Ru(DTDP)2](PF 6)4 exhibited enhanced ECL intensities as high as 3.6 times greater than that of the reference, [Ru(o-phen)3](PF 6)2.
Color-tunable white-light of binary tris-β-diketonate-(Dy3+, Gd3+ x) complexes’ blend under single wavelength excitation
Shi, Qi,Liu, Jiaxiang,Wang, Jia,Yang, Xiaohui,Zhang, Xingmei,Li, Shuna,Sun, Ping,Chen, Jin,Li, Beibei,Lü, Xingqiang
, (2020)
Based on the Dy3+-centered yellow-light and the ligands-based blue-light of the iso-structural two complexes [Ln(acac)3(5-Br-2,2′-bpy)] (Ln3+ = Dy3+ (2) or Gd3+ (3); Hacac = acetylacetone, 5-Br-2,2′-b
