Synthesis of heteroleptic pyrrolide/bipyridyl complexes of ruthenium(II)

LundriganTravis,; JacksonCarla, L M; Uddin, Imam; TuckerLloyd, A; Al-Sheikh, AliAdeeb; Linden, Anthony; Stanley, CameronT.; ThompsonAlison,

doi:10.1139/v2012-045

Cited by 17 publications

(26 citation statements)

References 35 publications

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“…Cambridge Structural Database (CSD) searches on 2-acylpyrroles reveal that there are also some other instances of 2-acylpyrroles which form dimers in the solid phase by N-H … O=C interactions [109][110][111][112][113][114][115][116][117][118][119][120][121][122][123][124][125]. Table 3 Table 2: Geometrical, and topological parameters of X-H … O=C hydrogen bonds (in Å and degrees) with H-bond energies E HB in kcal mol -1 of 2-acylpyrrole dimers calculated at the B3LYP/6-311++G(d,p) level of theory; data calculated at B3LYP/6-311+G* are given in parentheses.…”

Section: O Hydrogen Bondsmentioning

confidence: 99%

Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT Studies

Dubis

2014

J Phys Chem Biophys

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2-carboxylic acids [3] and corresponding esters [4]. Pyrrole-2-carboxylates are also useful substrates for the preparation of more complex pyrrole containing systems [5] such as ketorolac, a drug with anti-inflammatory and analgesic properties [6]. It is noted that the 2-acylpyrrole motif is widespread in nature. There are many examples of 2-acylpyrrole based molecules (Figure 1) with various biological activities [7,8]. Representative examples are pyoluteorin and pyrrolomycin D, secondary metabolites produced by marine Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT StudiesAlina T Dubis* Institute of Chemistry, University of Białystok, Hurtowa 1, Poland AbstractConformations of alpha-substituted pyrroles have been effectively studied using spectroscopic methods assisted by theoretical calculations developed in the recent decade. The question of how to effectively study the conformation of 2-acylpyrrole no longer remains unanswered. The detailed spectroscopic studies conducted in the last decade and interpreted on the basis of theoretical calculations provide a satisfactory answer to that question. Based on the Density Functional Theory (DFT) calculations of conformational properties of 2-acylpyrroles, for which two stable rotameric forms were predicted, syn and anti-conformers have been studied either by experimental or theoretical methods. The family of 2-acylpyrroles have both a proton donor N-H group and a proton acceptor C=O group. This structure favors the formation of doubly hydrogen-bonded cyclic dimers connected by two N-H...O=C bonds. The tendency to form cyclic dimers stabilizes the syn-conformation. Due to these properties 2-acylpyrroles can be used as structural models for the conformational analysis of peptides.This review summarizes recent investigations of conformations of 2-acylpyrroles, with a particular emphasis on the hydrogen bonds forming within these systems. The influence of 2-substitution on different aspects of stability of these molecular systems and the usefulness of infrared spectroscopy supported by theoretical calculations in H-bonds and conformational studies are discussed. Among the molecular properties hydrogen bond energy, structural characteristics such as C=O bond length of dimers and unique spectral features of 2-acylpyrroles that can be used to predict and investigate the conformation and structure of proteins are considered.Graphical abstract. The potential energy diagram of 2-acylpyrroles as a function of the dihedral angle pyrrole ringcarbonyl group of bond rotation. Most stable conformer syn converts to conformer anti via the transition state TS1; less stable conformer anti converts to conformer syn via the transition state TS2. conformational research and can greatly support experimental work with quite good accuracy. Among the most useful parameters are geometrical parameters, relative conformational energies, barriers to internal rotation and vibrational frequencies for each conformer. Journal of Physical Chemistry & BiophysicsEnergy differ...

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Section: O Hydrogen Bondsmentioning

confidence: 99%

Conformational Preferences of 2-Acylpyrroles in Light of FT-IR and DFT Studies

Dubis

2014

J Phys Chem Biophys

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“…We have previously reported the first synthesis of heteroleptic pyrrolyl/2,2′-bypyridyl complexes of ruthenium (II). 67 Considering the high stability and unusual UV/vis properties of these monoruthenium complexes, we now explore the synthesis and properties of symmetric bis(ruthenium) complexes of this type, with the goal of determining the effect of varying the extent of conjugation in these bis[Ru(II)-pyrrolide] triads. Initial studies concerned the design and synthesis of a monopyrrolic ligand bearing extended conjugation, with intent to optimize the synthetic protocol.…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

“…Initial studies concerned the design and synthesis of a monopyrrolic ligand bearing extended conjugation, with intent to optimize the synthetic protocol. 67,78 As such, N-Boc-2-vinyl pyrrole (1a) 79 was synthesized in a two-step procedure from 2-formyl pyrrole and, following a modified procedure, 80 was successfully employed as a Heck substrate with bromobenzene, providing the in situ-deprotected styryl-pyrrole 2a in good yield (64%, Scheme 1). Employing 1,4-dibromobenzene as the aryl halide along with 2 equivalents of vinylpyrrole 1a resulted in the conjugated, symmetric bis(pyrrole) 2b in high yield (86%).…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

“…Previously, we have shown that 2-formyl and 2-keto pyrroles can replace one of the 2,2′-bipyridyl (bpy) ligands in [Ru(bpy)3] 2+ to form stable complexes under ambient conditions with MLCT states shifted as much as 1.52 eV relative to the parent complex. 67 In these model mononuclear complexes, continuous absorption out to 600 nm was achieved without the need for sterically-demanding diimines such as 2,2′-biquinoline (biq) that are known to lower the energies of both MLCT and MC states, leading to red-shifted absorption, but also photodissociation. The small, bidentate pyrrolide ligand forms strong N- ( 1 ) bonds to Ru(II), lowering the energy of MLCT states without promoting ligand loss from dissociative MC states.…”

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confidence: 99%

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Bis[Pyrrolyl Ru(II)] Triads: a New Class of Photosensitizers for Metal-Organic Photodynamic Therapy

Smithen¹,

Monro²,

Pinto³

et al. 2020

Preprint

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A new family of ten dinuclear Ru(II) complexes based on the bis[pyrrolyl Ru(II)] triad scaffold, where two Ru(bpy)2 centers are separated by a variety of organic linkers, was prepared to evaluate the influence of the organic chromophore on the spectroscopic and in vitro photodynamic therapy (PDT) properties of the compounds. The bis[pyrrolyl Ru(II)] triads absorbed strongly throughout the visible region, with several members having molar extinction coefficients (e) ≥104 at 600–620 nm and longer. Phosphorescence quantum yields were generally less than 0.1% and in some cases undetectable. The singlet oxygen quantum yields ranged from 5% to 77% and generally correlated with their photocytotoxicities toward human leukemia (HL-60) cells regardless of the wavelength of light used. Dark cytotoxicities varied ten-fold, with EC50 values in the range of 10–100 µM and phototherapeutic indices (PIs) as large as 5,400 and 260 with broadband visible (28 J cm-2, 7.8 mW cm-2) and 625-nm red (100 J cm-2, 42 mW cm-2) light, respectively. The bis[pyrrolyl Ru(II)] triad with a pyrenyl linker (5h) was especially potent, with an EC50 value of 1 nM and PI >27,000 with visible light and subnanomolar activity with 625-nm light (100 J cm-2, 28 mW cm-2). The lead compound 5h was also tested in a tumor spheroid assay using the HL60 cell line and exhibited greater photocytotoxcicity in this more resistant model (EC50=60 nM and PI>1,200 with 625-nm light) despite a lower dark cytotoxicity. The in vitro PDT effects of 5h extended to bacteria, where submicromolar EC50 values and PIs >300 against S. mutans and S. aureus were obtained with visible light. This activity was attenuated with 625-nm red light, but PIs were still near 50. The ligand-localized 3ππ* state contributed by the pyrenyl linker of 5h likely plays a key role in its phototoxic effects toward cancer cells and bacteria.

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“…Mass spectra were obtained using TOF and LCQ Duo ion trap instruments operating in ESI +/− mode or APCI, as indicated. Compounds 1a-h 25,27,[38][39][40][41][42] were prepared according to literature procedures.…”

Section: Generalmentioning

confidence: 99%