Search results for "Complexes"

Quantitative EPR study of Mn(II)salen oxidation within zeolite Y

2000

Intermolecular hydrogen bonding in isostructural pincer complexes [OH-(t-BuPOCOPt-Bu)MCl] (M = Pd and Pt)

2019

In the crystal structure of the isostructural title compounds, namely {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridopalladium(II), [Pd(C22H39O3P2)Cl], 1, and {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridoplatinum(II), [Pt(C22H39O3P2)Cl], 2, the metal centres are coordinated in a distorted square-planar fashion by the POCOP pincer fragment and the chloride ligand. Both complexes form strong hydrogen-bonded chain structures through an interaction of the OH group in the 4-position of the aromatic POCOP backbone with the halide ligand. © 2019.

Impact of Vanadium Complexes with Tetradentate Schiff Base Ligands on the DPPC and EYL Liposome Membranes: EPR Studies

2023

This paper investigates the effect of three vanadium complexes with Schiff base-type tetradentate ligands of general formula N,N′-1,2-cyclohexylenebis(3,5-dichlorosalicylideneiminate) (V1); LVCl2 (L = N,N′-1,2-cyclohexylenebis(5-chlorosalicylideneiminate) (V2); and N,N′-1,3propylenebis (salicylideneiminate) (V3) on the fluidity of liposome membranes obtained by the sonication of natural lecithin (EYL) and synthetic lecithin (DPPC). The study was carried out with TEMPO and 16DOXYL spin probes using the EPR technique. The results show that the effect of the complexes on the fluidity of liposomes whose membranes are in the liquid crystalline phase is much stronger as compared to the liposome m…

Insights into the decomposition pathway of a lutetium alkylamido complex via intramolecular C–H bond activation

2017

Synthesis, characterization and reaction chemistry of lutetium alkylamido LLu(CH2SiMe3)(NHCPh3) (2), L = 2,5-[Ph2P=N(4-iPrC6H4)]2N(C4H2)–, is reported. Complex 2 undergoes cyclometalation of the NHCPh3 ligand at elevated temperatures to produce the orthometalated complex LLu(κ2−N,C-(NHCPh2(C6H4))) (3) which converts to 0.5 equivalents of bis(amido) LLu(NHCPh3)2 (4) upon heating at 80 °C for 24 h. Reaction of complex 2 with 4-dimethylaminopyridine (DMAP) does not promote alkane elimination nor imido formation. A kinetic analysis of the thermal decomposition of complex 2, supported by deuterium labelling studies and computational analysis (PBE0/def2-TZVP/SDD(Lu)), indicate direct Csp2–H activ…

Magneto-Structural Properties and Theoretical Studies of a Family of Simple Heterodinuclear Phenoxide/Alkoxide Bridged MnIIILnIII Complexes : On the …

2018

A family of MnIIILnIII strictly dinuclear complexes of general formula [MnIII(μ-L)(μ-OMe)(NO3)LnIII(NO3)2(MeOH)] (LnIII = Gd, Dy, Er, Ho) has been assembled in a one pot synthesis from a polydentate, multipocket aminobis(phenol)ligand [6,6'-{(2-(1-morpholyl)ethylazanediyl)bis(methylene)}bis(2-methoxy-4-methylphenol)], Mn(NO3)2·4H2O, Ln(NO3)3· nH2O, and NEt3 in MeOH. These compounds represent the first examples of fully structurally and magnetically characterized dinuclear MnIIILnIII complexes. Single X-ray diffraction studies reveal that all complexes are isostructural, consisting of neutral dinuclear molecules where the MnIII and LnIII metal ions, which exhibit distorted octahedral MnN2O4 …

Single-molecule magnet properties of a monometallic dysprosium pentalene complex

2018

The pentalene-ligated dysprosium complex [(η8-Pn†)Dy(Cp*)] (1Dy) (Pn† = [1,4-(iPr3Si)2C8H4]2−) and its magnetically dilute analogue are single-molecule magnets, with energy barriers of 245 cm−1. Whilst the [Cp*]− ligand in 1Dy provides a strong axial crystal field, the overall axiality of this system is attenuated by the unusual folded structure of the [Pn†]2− ligand. peerReviewed

Theoretical investigation of magnetic properties in Cu(II) complexes with bridging azide ions

2011

Antiapoptotic effect of calcitonin gene-related peptide on oxidative stress-induced injury in H9c2 cardiomyocytes via the RAMP1/CRLR complex.

2005

Calcitonin gene-related peptide (CGRP) plays an important role in the mediation of protective effects observed in situations such as ischemic preconditioning in rat hearts. In this study, we investigated in H9c2 rat cardiomyoblasts if the protective effect of CGRP could be linked to an inhibitory effect on the apoptotic pathway. We also determined the specificity of observed effects by treatment with adrenomedullin (ADM) in stress conditions generated by 100 microM hydrogen peroxide. Using MTT assays, we demonstrate that a pretreatment with CGRP decreases by half the loss of cell viability induced by H(2)O(2). CGRP inhibits phosphatidylserine externalization, caspase 3 activation and DNA fr…

Dofetilide effects on the inhibition by trains of subthreshold conditioning stimuli.

2004

We investigated the electrophysiological actions of dofetilide upon the ventricular myocardium to determine whether the drug modifies the inhibitory effects of subthreshold stimuli trains upon ventricular refractoriness. In nine Langendorff perfused rabbit hearts, ventricular epicardial electrodes were used to determine the following parameters at baseline and during dofetilide perfusion (0.5 micromolar): effective (ERP) and functional (FRP) refractory periods, conduction velocity (CV), wavelength (WL), and ERP prolongation (inhibitory effect) induced by subthreshold stimuli trains (STr) at pulse frequencies of 100, 300, and 600 Hz. Dofetilide significantly prolongs ventricular refractorine…

Visualizing the atherosclerotic plaque: a chemical perspective.

2014

Atherosclerosis is the major underlying pathologic cause of coronary artery disease. An early detection of the disease can prevent clinical sequellae such as angina, myocardial infarction, and stroke. The different imaging techniques employed to visualize the atherosclerotic plaque provide information of diagnostic and prognostic value. Furthermore, the use of contrast agents helps to improve signal-to-noise ratio providing better images. For nuclear imaging techniques and optical imaging these agents are absolutely necessary. We report on the different contrast agents that have been used, are used or may be used in future in animals, humans, or excised tissues for the distinct imaging moda…