Search results for "Triplet"
showing 10 items of 159 documents
Coexistence of superconductivity and spin-splitting fields in superconductor/ferromagnetic insulator bilayers of arbitrary thickness
2021
Ferromagnetic insulators (FI) can induce a strong exchange field in an adjacent superconductor (S) via the magnetic proximity effect. This manifests as spin splitting of the BCS density of states of the superconductor, an important ingredient for numerous superconducting spintronics applications and the realization of Majorana fermions. A crucial parameter that determines the magnitude of the induced spin splitting in FI/S bilayers is the thickness of the S layer d: In very thin samples, the superconductivity is suppressed by the strong magnetism. By contrast, in very thick samples, the spin splitting is absent at distances away from the interface. In this work, we calculate the density of …
Excited-State Kinetics of an Air-Stable Cyclometalated Iron(II) Complex.
2019
The complex class [Fe(N^N^C)(N^N^N)]+ with an Earth-abundant metal ion has been repeatedly suggested as a chromophore and potential photosensitizer on the basis of quantum chemical calculations. Synthesis and photophysical properties of the parent complex [Fe(pbpy)(tpy)]+ (Hpbpy=6-phenyl-2,2'-bipyridine and tpy=2,2':6',2''-terpyridine) of this new chromophore class are now reported. Ground-state characterization by X-ray diffraction, electrochemistry, spectroelectrochemistry, UV/Vis, and X-ray spectroscopy in combination with DFT calculations proves the high impact of the cyclometalating ligand on the electronic structure. The photophysical properties are significantly improved compared to …
Theoretical Investigation of the Low-Energy States of CpMoCl(PMe 3 ) 2 and Their Role in the Spin-Forbidden Addition of N 2 and CO
2003
International audience; A recent computational investigation of Jahn−Teller effects in unsaturated 16-electron d4d6 [CpMLn] complexes (Abu-Hasanayn, F.; Cheong, P.; Oliff, M. Angew. Chem.2002, 41, 2120) highlighted the typical presence of two spin-triplet and two singlet states of competing stability in these complexes and pointed out the necessity to account for more than one electronic state in studies thereof. Consequently, we have reinvestigated the addition of N2 to all the four low-energy states of CpMoCl(PH3)2, a reaction for which previously only one singlet and one triplet state have been considered (Keogh, D. W.; Poli, R. J. Am. Chem. Soc.1997, 119, 2516). The present study was pe…
Cobaltocenium substituents as electron acceptors in photosynthetic model dyads
2017
Abstract Cobaltocenium carboxylic acid hexafluorophosphate has been attached to a zinc(II) meso-tetraphenyl porphyrin chromophore via an amide linkage. Optical and electrochemical studies reveal that the metallocene and the porphyrin interact only negligibly in the ground state of the dyad. Photoinduced charge-shift from the zinc porphyrin to the cobaltocenium substituent to give the zinc porphyrin radical cation and the cobaltocene occurs upon exciting the porphyrin with light. Steady state emission, time-resolved fluorescence and transient absorption pump–probe spectroscopy in addition to density functional theory calculations suggest that the charge shift to the cobaltocenium substituent…
Theoretical investigation of the spin crossover transition states of the addition of methane to a series of Group 6 metallocenes using minimum energy…
2016
International audience; Density functional calculations are reported on the addition of methane to Group 6 metallocenes, M(η-C5H5)2 (M), M(CH2(η-C5H4)2) (a-M) and M(η-C5Me5)2 (M*) where M = Mo and W. Full geometry optimisations were carried out on the singlet and triplet 16 electron complexes, 1[M] and 3[M], the η2-methane complexes, 1[M(η2-CH4)], and the hydridomethyl adducts, 1[M(CH3)(H)]. The triplet state for [M] was found to be more stable for all six metallocenes, the difference being least in the case of the ansa-bridged system. Formation of the hydridomethyl complexes was exoenergetic for all tungsten systems and for a-Mo, the other two Mo systems being endoenergetic. Minumum energy…
rbFOX1/MBNL1 competition for CCUG RNA repeats binding contributes to myotonic dystrophy type 1/type 2 differences
2018
Myotonic dystrophy type 1 and type 2 (DM1, DM2) are caused by expansions of CTG and CCTG repeats, respectively. RNAs containing expanded CUG or CCUG repeats interfere with the metabolism of other RNAs through titration of the Muscleblind-like (MBNL) RNA binding proteins. DM2 follows a more favorable clinical course than DM1, suggesting that specific modifiers may modulate DM severity. Here, we report that the rbFOX1 RNA binding protein binds to expanded CCUG RNA repeats, but not to expanded CUG RNA repeats. Interestingly, rbFOX1 competes with MBNL1 for binding to CCUG expanded repeats and overexpression of rbFOX1 partly releases MBNL1 from sequestration within CCUG RNA foci in DM2 muscle ce…
Real life triplet FIr/FOx chemotherapy in first-line metastatic pancreatic ductal adenocarcinoma patients: Recommended schedule for expected activity…
2018
// Gemma Bruera 1, 2 , Silvia Massacese 3 , Stefania Candria 1 , Antonio Galvano 4 , Rosa Manetta 5 , Aldo Victor Giordano 5 , Sergio Carducci 5 , Alessandra Di Sibio 5 , Eugenio Ciacco 3 , Antonio Russo 4 , Enrico Ricevuto 1, 2 and on behalf of Oncology Network ASL1 Abruzzo, Italy 1 Oncology Territorial Care Unit, S. Salvatore Hospital, Oncology Network ASL1 Abruzzo, University of L’Aquila, L’Aquila, Italy 2 Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L’Aquila, Italy 3 Pharmacy Unit, S. Salvatore Hospital, Oncology Network ASL1 Abruzzo, L’Aquila, Italy 4 Medical Oncology Unit, Department of Surgical, Oncological and Stomatological Sciences, Univers…
Dose-finding study of intensive weekly alternating schedule of docetaxel, 5-fluorouracil, and oxaliplatin, FD/FOx regimen, in metastatic gastric canc…
2018
// Gemma Bruera 1, 2 , Silvia Massacese 3 , Antonio Galvano 4 , Antonella Dal Mas 5 , Stefano Guadagni 6, 2 , Giuseppe Calvisi 5 , Eugenio Ciacco 3 , Antonio Russo 4 , Enrico Ricevuto 1, 2 , on behalf of Oncology Network ASL1 Abruzzo, Italy 1 Oncology Territorial Care, S. Salvatore Hospital, Oncology Network ASL1 Abruzzo, University of L'Aquila, L'Aquila, Italy 2 Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L’Aquila, Italy 3 Pharmacy Unit, S. Salvatore Hospital, Oncology Network ASL1 Abruzzo, L’Aquila, Italy 4 Medical Oncology, Department of Surgical, Oncological and Stomatological Sciences, University of Palermo, Palermo, Italy 5 Pathology, S. Salva…
Synthesis and antiproliferative mechanism of action of pyrrolo[3′,2′:6,7] cyclohepta[1,2-d]pyrimidin-2-amines as singlet oxygen photosensitizers
2016
A new series of pyrrolo[3′,2′:6,7]cyclohepta[1,2-d]pyrimidin-2-amines, was conveniently prepared using a versatile and high yielding multistep sequence. A good number of derivatives was obtained and the cellular photocytotoxicity was evaluated in vitro against three different human tumor cell lines with EC50 (0.08–4.96 μM) values reaching the nanomolar level. Selected compounds were investigated by laser flash photolysis. The most photocytotoxic derivative, exhibiting a fairly long-lived triplet state (τ ∼ 7 μs) and absorbance in the UV–Vis, was tested in the photo-oxidations of 9,10-anthracenedipropionic acid (ADPA) by singlet oxygen. The photosentizing properties are responsible for the c…
Photophysical behavior of 3-methylquinoline and 3-bromoquinoline
1992
Abstract The phosphorescence emission and excitation spectra and their polarizations have been studied for 3-methylquinoline and 3-bromoquinoline in methylcyclohexane and ethanol glasses at 77 K. From the results obtained in 3-methylquinoline (τp = 1.30 s in ethanol, τp = 1.05 s in methylcyclohexane and the out-of-plane polarization) it is concluded that the emission originates from a triplet state of 3ππ∗ character. In 3-bromoquinoline, the phosphorescence lifetimes (ca. 8 ms in a non-polar solvent and 15 ms in a polar solvent) and the negative degree of polarization indicate an emitting state of ππ∗ character that is strongly coupled to a higher-lying triplet state of the nπ∗ type. The mo…