Search results for "Halogen"

High temperature ferro-paraelectric phase transition in tris(trimethylammonium) nonachlorodiantimonate(III) (TMACA) studied by X-ray diffraction meth…

2000

Abstract The structure of [NH(CH3)3]3Sb2Cl9, tris(trimethylammonium) nonachlorodiantimonate(III) (TMACA) has been determined at 295 K and 373 K, below and above the high temperature ferro-paraelectric phase transition. In both phases the anionic sublattice of TMACA is built of characteristic two-dimensional (Sb2Cl93−)n polyanionic layers lying in the bc plane. In room temperature, ferroelectric phase (monoclinic, Pc space group) there are three crystallographically non-equivalent trimethylammonium [NH(CH3)3]+ cations. Two of them are located between polyanionic layers and the third one, disordered, inside the cavity formed by six SbCl63− octahedra. In the high temperature paraelectric phase…

Legacy and Emerging Contaminants in Demersal Fish Species from Southern Norway and Implications for Food Safety

2020

The present study aimed at measuring the levels of legacy and emerging contaminants in fillet samples from four demersal fish caught in two fishing sites from Southern Norway, in order to assess possible implications for food safety. Levels of organochlorine compounds (OCs), organophosphate pesticides (OPs), polychlorinated biphenyls (PCBs), polybromodiphenyl ethers (PBDE), per- and polyfluoroalkyl substances (PFASs), and polycyclic aromatic hydrocarbons (PAHs) were measured in fillet from Atlantic cod (Gadus morhua), European plaice (Pleuronectes platessa), lemon sole (Microstomus kitt), and European flounder (Platichthys flesus) specimens. A negligible contamination by all the investigate…

Induction of Hsp70 by the Herbicide Oxyfluorfen (Goal) in the Egyptian Nile Fish, Oreochromis niloticus

1999

This paper deals with the expression of the biomarker hsp70 in the liver and kidney of the freshwater fish Oreochromis niloticus following exposure to the herbicide oxyfluorfen (Goal). Fishes were exposed to three concentrations, the 96-h LC50 (3 mg/L), the 96-h (1/2)LC50 (1.5 mg/L), and the 96-h (1/4)LC50 (0.75 mg/L) of oxyfluorfen for 6, 15, and 24 days, respectively, and samples were taken at three different time periods for each concentration. The livers responded to the herbicide by an induction of the expression of both the constitutive (hsp75; Mr 75 kDa) and the inducible (hsp73; Mr 73 kDa) hsp70 proteins. In kidney, the herbicide induced a time-dependent increase in the expression o…

2018

Volcanoes are a significant halogen source to the atmosphere. After water, carbon dioxide and sulfur compounds, halogens are often the most abundant gases in volcanic plumes. In the past, less attention was given to the heavy halogens bromine and iodine. However, the discovery of bromine monoxide (BrO) in volcanic plumes led to new interest especially in volcanic bromine chemistry and its impact on atmospheric processes. The BrO detection came along with advances in volcanic remote sensing techniques, in particular, robust DOAS applications and the possibility of continuous measurements by automated instruments located at safe distances from the volcano. As one of the consequences, the volc…

BrO formation in volcanic plumes

2006

Volcanoes have only recently been recognized as a potentially major source of reactive bromine species to the atmosphere, following from the detection of bromine monoxide (BrO) in the plume emitted by Soufriere Hills Volcano, Montserrat. However, BrO is not expected to be emitted in significant quantity from magma, presenting a puzzle regarding its formation. We report here new field measurements of the tropospheric plume emitted by Mt. Etna, Italy, which provide the first direct evidence of fast oxidation of halogen species in a volcanic plume, and lead to an explanation of how BrO is generated from magmatic HBr emissions. We show that the timescale of BrO formation (a few minutes after em…

AEROBIC 1,2-DICHLOROETHANE DEGRADERS IN CONTAMINATED GROUNDWATER

2022

Iodine(I) and Silver(I) Complexes of Benzoimidazole and Pyridylcarbazole Derivatives

2021

The synthesis of iodine(I) complexes with either benzoimidazole or carbazole-derived sp 2 N -containing Lewis bases is described, as well as their corresponding silver(I) complexes. The addition of elemental iodine to the linear two-coordinate Ag(I) complexes produces iodine(I) complexes with a three-center four-electron (3c-4e) [N — I — N] + bond. The 1 H and 1 H- 15 N HMBC NMR studies unambiguously confirm the formation of the complexes in all cases via the [N — Ag — N] + → [N — I — N] + cation exchange, with the 15 N NMR chemical shift change between 94 to 111 ppm when compared to the free ligand. The single crystal X-ray crystallographic studies on four I + complexes revealed highly sym…

Design and construction of halogen-bonded capsules and cages

2017

This thesis describes the design, synthesis and characterization of supramolecular halogen-bonded capsules and cages from multivalent ligands. In the first part of the thesis, an overview to halogen bonding is provided. After discussing the general features of the halogen bonding, the most frequently used halogen bond donors are introduced and examples of their utilization in halogen-bonded systems are discussed. The chapter also presents recent advances made in the field of halogen-bonded supramolecular capsules. The first part of the thesis also includes a review of halogen-bonded complexes involving halonium ions, and a brief introduction to [N···X+···N] halogen bonds is provided along w…

Halogen Bonds in Square Planar 2,5-Dihalopyridine-Copper(II) Bromide Complexes

2018

The “nitrogen effect” : Complexation with macrocycles potentiates fused heterocycles to form halogen bonds in competitive solvents

2023

Weak intermolecular forces are typically very difficult to observe in highly competitive polar protic solvents as they are overwhelmed by the quantity of competing solvent. This is even more challenging for three-component ternary assemblies of pure organic compounds. In this work, we overcome these complications by leveraging the binding of fused aromatic N-heterocycles in an open resorcinarene cavity to template the formation of a three-component halogen-bonded ternary assembly in a protic polar solvent system. peerReviewed