17 research outputs found
From Induced-Fit Assemblies to Ternary Inclusion Complexes with Fullerenes in Corannulene-Based Molecular Tweezers
Producción CientíficaThe participation of the tether moiety in fullerene recognition of corannulene-based molecular tweezers is known to be an important factor. In the present work, we describe the synthesis of a set of fullerene receptors bearing two corannulene units located at a suitable distance to effectively interact with C60 and C70. The tether comprises a fluorene-like scaffold where an assortment of different groups with variable electronic properties has been grafted. The photophysical and electrochemical properties of all final compounds have been unveiled and correlated to the donor/acceptor (DA) nature of the tether. Despite these strong variations, their affinity toward fullerenes cannot be correlated in any way to simple DA behavior as the main contribution to the interaction correspond to London dispersion forces. We found, however, that the sulfur-derived subfamily is able to adapt better to the fullerene outer surface slightly increasing the charge transfer and electrostatic attractive interactions being the most outstanding example the case of thiophene 4-S with C70 as it is capable of forming a ternary 2:1 inclusion complex in solution with an electronic binding energy that offsets entropy and desolvation penalties typically associated with higher-order inclusion complexes.Ministerio de Ciencia, Innovación y Universidades (project (projects numbers PGC2018-096880-A-I00, MCIU/AEI/FEDER, UE, PGC2018-099470-B-I00, and MCIU/AEI/FEDER, UE
Luminescent cis-Bis(bipyridyl)ruthenium(II) Complexes with 1,2-Azolylamidino Ligands: Photophysical, Electrochemical Studies, and Photocatalytic Oxidation of Thioethers
Producción CientíficaNew 1,2-azolylamidino complexes cis-[Ru(bipy)2(NH═C(R)az*-κ2N,N)](OTf)2 (R = Me, Ph; az* = pz, indz, dmpz) are synthesized via chloride abstraction after a subsequent base-catalyzed coupling of a nitrile with the previously coordinated 1,2-azole. The synthetic procedure allows the easy obtainment of complexes having different electronic and steric 1,2-azoylamidino ligands. All of the compounds have been characterized by 1H, 13C, and 15N NMR and IR spectroscopy and by monocrystal X-ray diffraction. Photophysical studies support their phosphorescence, whereas their electrochemistry reveals reversible RuII/RuIII oxidations between +1.13 and +1.25 V (vs SCE). The complexes have been successfully used as catalysts in the photooxidation of different thioethers, the complex cis-[Ru(bipy)2(NH═C(Me)dmpz-κ2N,N)]2+ showing better catalytic performance in comparison to that of [Ru(bipy)3]2+. Moreover, the significant catalytic performance of the dimethylpyrazolylamidino complex is applied to the preparation of the drug modafinil, which is obtained using ambient oxygen as an oxidant. Finally, mechanistic assays suggest that the oxidation reaction follows a photoredox route via oxygen radical anion formation.Ministerio de Economía, Industria y Competitividad (grants PGC2018- 099470-B-I00 and RTI2018-095038-B-I00)Junta de Castilla y León (grant VA130618)Junta de Castilla y León - Fondo Social Europeo (project BU263P18
Self-Assembly Hydrosoluble Coronenes: A Rich Source of Supramolecular Turn-On Fluorogenic Sensing Materials in Aqueous Media
Water-soluble coronenes, that form nanoparticles by self-association, work as new fluorescent materials by complexation with cucurbit[7]uril, as well as selective turn-on fluorogenic sensors for nitroaromatic explosives with remarkable selectivity, by using only water as solvent.NATO Science for Peace and Security Programme (SPS G5536), Ministerio de Ciencia, Innovación y Universidades-FEDER (PID2019-111215RB-100 and RTI2018-102040-B-100), Junta de Castilla y León, Consejería de Educación y Cultura y Fondo Social Europeo (BU263P18) and “la Caixa” Foundation (LCF/PR/PR12/11070003) for financial support. A.R.C. thanks Secretaría General de Universidades (FPU18/03225)
Multicomponent Prins Cyclization from Allylsilyl Alcohols Leading to Dioxaspirodecanes
A multicomponent reaction for the preparation of dioxaspirodecanes starting from allylsilyl alcohols was achieved. The one-pot sequence involves the sequential acid-catalyzed reaction of an allylsilyl alcohol with an aldehyde to afford an alkenediol. The subsequent Prins cyclization of the homoallylic alcohol moiety generates a tetrahydropyranyl carbocation which is intramolecularly trapped by the second hydroxyl group. The chemoselectivity of the process shows dependence on the nature of the aldehyde and the concentration of the catalyst
One‐step Oxidative Monofluorination of Electron‐deficient Sulfoxides to Access Highly Lewis Acidic Sulfur(VI) Cations
International audienc
Synthesis of Azepane Derivatives by Silyl-aza-Prins Cyclization of Allylsilyl Amines: Influence of the Catalyst in the Outcome of the Reaction
The synthesis of
seven-membered nitrogen heterocycles by silyl-aza-Prins
cyclization is described. The process provides <i>trans</i>-azepanes in high yields and good to excellent diastereoselectivities.
Moreover, the reaction outcome is dependent on the Lewis acid employed.
Thus, while azepanes are selectively obtained when InCl<sub>3</sub> is used, the reaction in the presence of TMSOTf provides tetrahydropyran
derivatives corresponding to a tandem Sakurai–Prins cyclization
Luminescent Rhenium(I)tricarbonyl Complexes Containing Different Pyrazoles and Their Successive Deprotonation Products: CO2 Reduction Electrocatalysts
Cationic fac-[Re(CO)3(pz*H)(pypzH)]OTf
(pz*H = pyrazole, pzH; 3,5-dimethylpyrazole, dmpzH; indazole,
indzH; 3-(2-pyridyl)pyrazole, pypzH) were obtained from fac-
[ReBr(CO)3(pypzH)] by halide abstraction with AgOTf and
subsequent addition of the corresponding pyrazole. Successive
deprotonation with Na2CO3 and NaOH gave neutral fac-
[Re(CO)3(pz*H)(pypz)] and anionic Na{fac-[Re(CO)3(pz*)-
(pypz)]} complexes, respectively. Cationic fac-[Re(CO)3(pz*H)-
(pypzH)]OTf, neutral complexes fac-[Re(CO)3(pz*H)(pypz)],
and fac-[Re(CO)3(pypz)2Na] were subjected to photophysical and
electrochemical studies. They exhibit phosphorescent decays from
a prevalently 3MLCT excited state with quantum yields (Φ) in the
range between 0.03 and 0.58 and long lifetimes (τ from 220 to 869 ns). The electrochemical behavior in Ar atmosphere of cationic
and neutral complexes indicates that the oxidation processes assigned to ReI → ReII occurs at lower potentials for the neutral
complex compared to cationic complex. The reduction processes occur at the ligands and do not depend on the charge of the
complexes. The electrochemical behavior in CO2 saturated media is consistent with CO2 electrocatalyzed reduction, where the
values of the catalytic activity [icat(CO2)/icat(Ar)] ranged from 2.7 to 11.5 (compared to 8.1 for fac-[Re(CO)3Cl(bipy)] studied as a
reference). Controlled potential electrolysis for the pyrazole cationic (3a) and neutral (4a) complexes after 1 h affords CO in faraday
yields of 61 and 89%, respectively. These values are higher for indazole complexes and may be related to the acidity of the
coordinated pyrazole
(1,2-Azole)bis(bipyridyl)ruthenium(II) Complexes: Electrochemistry, Luminescent Properties, And Electro- And Photocatalysts for CO2 Reduction
New cis-(1,2-azole)-aquo bis(2,2′-bipyridyl)ruthenium(II) (1,2-azole (az*H) = pzH (pyrazole), dmpzH (3,5-dimethylpyrazole), and indzH (indazole)) complexes are synthesized via chlorido abstraction from cis-[Ru(bipy)2Cl(az*H)]OTf. The latter are obtained from cis-[Ru(bipy)2Cl2] after the subsequent coordination of the 1,2-azole. All the compounds are characterized by 1H, 13C, 15N NMR spectroscopy as well as IR spectroscopy. Two chlorido complexes (pzH and indzH) and two aquo complexes (indzH and dmpzH) are also characterized by X-ray diffraction. Photophysical and electrochemical studies were carried out on all the complexes. The photophysical data support the phosphorescence of the complexes. The electrochemical behavior of all the complexes in an Ar atmosphere indicate that the oxidation processes assigned to Ru(II) → Ru(III) occurs at higher potentials in the aquo complexes. The reduction processes under Ar lead to several waves, indicating that the complexes undergo successive electron-transfer reductions that are centered in the bipy ligands. The first electron reduction is reversible. The electrochemical behavior in CO2 media is consistent with CO2 electrocatalyzed reduction, where the values of the catalytic activity [icat(CO2)/ip(Ar)] ranged from 2.9 to 10.8. Controlled potential electrolysis of the chlorido and aquo complexes affords CO and formic acid, with the latter as the major product after 2 h. Photocatalytic experiments in MeCN with [Ru(bipy)3]Cl2 as the photosensitizer and TEOA as the electron donor, which were irradiated with >300 nm light for 24 h, led to CO and HCOOH as the main reduction products, achieving a combined turnover number (TONCO+HCOO–) as high as 107 for 2c after 24 h of irradiation.Junta de Castilla y León (ref. VA130618). E.C. thanks the UVa for her grant. The authors in Valladolid gratefully acknowledge financial support from the Spanish MINECO, Spain (PGC2018-099470-B-I00) and Junta de Castilla y León (VA130618), and the authors in Burgos gratefully acknowledge financial support from the Junta de Castilla y León, Consejería de Educación y Cultura and Fondo Social Europeo (Project BU263P18). A.M.A.-B. is grateful for support from the National Science Foundation CAREER Grant (CHE-1652606)
Luminescent Rhenium(I)tricarbonyl Complexes Containing Different Pyrazoles and Their Successive Deprotonation Products: CO2 Reduction Electrocatalysts
Cationic fac-[Re(CO)3(pz*H)(pypzH)]OTf
(pz*H = pyrazole, pzH; 3,5-dimethylpyrazole, dmpzH; indazole,
indzH; 3-(2-pyridyl)pyrazole, pypzH) were obtained from fac-
[ReBr(CO)3(pypzH)] by halide abstraction with AgOTf and
subsequent addition of the corresponding pyrazole. Successive
deprotonation with Na2CO3 and NaOH gave neutral fac-
[Re(CO)3(pz*H)(pypz)] and anionic Na{fac-[Re(CO)3(pz*)-
(pypz)]} complexes, respectively. Cationic fac-[Re(CO)3(pz*H)-
(pypzH)]OTf, neutral complexes fac-[Re(CO)3(pz*H)(pypz)],
and fac-[Re(CO)3(pypz)2Na] were subjected to photophysical and
electrochemical studies. They exhibit phosphorescent decays from
a prevalently 3MLCT excited state with quantum yields (Φ) in the
range between 0.03 and 0.58 and long lifetimes (τ from 220 to 869 ns). The electrochemical behavior in Ar atmosphere of cationic
and neutral complexes indicates that the oxidation processes assigned to ReI → ReII occurs at lower potentials for the neutral
complex compared to cationic complex. The reduction processes occur at the ligands and do not depend on the charge of the
complexes. The electrochemical behavior in CO2 saturated media is consistent with CO2 electrocatalyzed reduction, where the
values of the catalytic activity [icat(CO2)/icat(Ar)] ranged from 2.7 to 11.5 (compared to 8.1 for fac-[Re(CO)3Cl(bipy)] studied as a
reference). Controlled potential electrolysis for the pyrazole cationic (3a) and neutral (4a) complexes after 1 h affords CO in faraday
yields of 61 and 89%, respectively. These values are higher for indazole complexes and may be related to the acidity of the
coordinated pyrazole
Integration of proteomics and transcriptomics data sets for the analysis of a lymphoma B-cell line in the context of the chromosome-centric human proteome project
et al.A comprehensive study of the molecular active landscape of human cells can be undertaken to integrate two different but complementary perspectives: transcriptomics, and proteomics. After the genome era, proteomics has emerged as a powerful tool to simultaneously identify and characterize the compendium of thousands of different proteins active in a cell. Thus, the Chromosome-centric Human Proteome Project (C-HPP) is promoting a full characterization of the human proteome combining high-throughput proteomics with the data derived from genome-wide expression profiling of protein-coding genes. Here we present a full proteomic profiling of a human lymphoma B-cell line (Ramos) performed using a nanoUPLC-LTQ-Orbitrap Velos proteomic platform, combined to an in-depth transcriptomic profiling of the same cell type. Data are available via ProteomeXchange with identifier PXD001933. Integration of the proteomic and transcriptomic data sets revealed a 94% overlap in the proteins identified by both -omics approaches. Moreover, functional enrichment analysis of the proteomic profiles showed an enrichment of several functions directly related to the biological and morphological characteristics of B-cells. In turn, about 30% of all protein-coding genes present in the whole human genome were identified as being expressed by the Ramos cells (stable average of 30% genes along all the chromosomes), revealing the size of the protein expression-set present in one specific human cell type. Additionally, the identification of missing proteins in our data sets has been reported, highlighting the power of the approach. Also, a comparison between neXtProt and UniProt database searches has been performed. In summary, our transcriptomic and proteomic experimental profiling provided a high coverage report of the expressed proteome from a human lymphoma B-cell type with a clear insight into the biological processes that characterized these cells. In this way, we demonstrated the usefulness of combining -omics for a comprehensive characterization of specific biological systems.We gratefully acknowledge financial support from the Carlos III Health Institute of Spain (ISCIII, FIS PI11/02114, FIS PI14/01538, and FIS PI12/00624), Fondos FEDER (EU) and Junta Castilla-León SA198A12-2. The Proteomics Unit belongs to ProteoRed, PRB2-ISCIII, supported by grant PT13/0001. P.D. and C.D. are supported by a JCYL-EDU/346/2013 Ph.D.
scholarship.Peer Reviewe