Stable Diporphyrinylaminyl Radical and Nitrenium Ion

2018 ◽  
Vol 57 (30) ◽  
pp. 9434-9438 ◽  
Author(s):  
Daiki Shimizu ◽  
Keisuke Fujimoto ◽  
Atsuhiro Osuka
Keyword(s):  
Nitrenium Ion

scholarly journals Time-Resolved Spectroscopic Study of N,N-Di(4-bromo)nitrenium Ions in Selected Solutions

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3182 ◽  
Author(s):  
Lili Du ◽  
Xin Lan ◽  
Zhiping Yan ◽  
Ruixue Zhu ◽  
David Phillips
Keyword(s):  
Transient Absorption ◽  
Direct Detection ◽  
Reaction Pathway ◽  
Addition Reactions ◽  
Time Resolved ◽  
Nitrenium Ions ◽  
Future Studies ◽  
Nitrenium Ion ◽  
Design Time

Nitrenium ions are important reactive intermediates in chemistry and biology. In this work, femtosecond and nanosecond transient absorption (fs-TA and ns-TA) along with nanosecond time-resolved resonance Raman (ns-TR3) experiments were employed to examine the photochemical pathways of N-(4,4′-dibromodiphenylamino)-2,4,6-trimethylpyridinium BF4− (salt (DN) from just absorption of a photon of light to the production of the important N,N-di(4-bromophenyl)nitrenium ion 2. In acetonitrile (MeCN), the formation of halogenated diarylnitrenium ion 2 was observed within 4 ps, showing the vibrational spectra with strong intensity. The nucleophilic adduct reaction of ion 2 with H2O was also examined in aqueous solutions. The direct detection of the unique ortho adduct intermediate 3 shows that there is an efficient and exclusive reaction pathway for 2 with H2O. The results shown in this paper give new characterization of 2, which can be used to design time-resolved spectroscopy investigations of covalent addition reactions of nitrenium ions with other molecules in future studies.

Nitrenium ions and trivalent boron ligands as analogues of N-heterocyclic carbenes in olefin metathesis: a computational study

2015 ◽  
Vol 44 (46) ◽  
pp. 20021-20026 ◽  
Author(s):  
A. Pazio ◽  
K. Woźniak ◽  
K. Grela ◽  
B. Trzaskowski
Keyword(s):  
Olefin Metathesis ◽  
Computational Study ◽  
Heterocyclic Carbenes ◽  
Mechanistic Study ◽  
Nitrenium Ions ◽  
Nitrenium Ion ◽  
Metathesis Catalysts

A DFT mechanistic study reveals that nitrenium ion-modified Hoveyda-like complexes are good candidates for latent metathesis catalysts, while boron-modified systems are candidates for very fast metathesis catalysts.

Stable Diporphyrinylaminyl Radical and Nitrenium Ion

2018 ◽  
Vol 130 (30) ◽  
pp. 9578-9582 ◽  
Author(s):  
Daiki Shimizu ◽  
Keisuke Fujimoto ◽  
Atsuhiro Osuka
Keyword(s):  
Nitrenium Ion

scholarly journals Time-Resolved Spectroscopic Study of N,N–Di(4–bromo)nitrenium Ions in Acidic Aqueous Solution

2019 ◽  
Vol 20 (21) ◽  
pp. 5512 ◽  
Author(s):  
Lili Du ◽  
Zhiping Yan ◽  
Xueqin Bai ◽  
Runhui Liang ◽  
David Lee Phillips
Keyword(s):  
Aqueous Solution ◽  
Transient Absorption ◽  
Function Theory ◽  
Spectroscopic Properties ◽  
Time Resolved ◽  
Nitrenium Ions ◽  
Acidic Aqueous Solution ◽  
Nitrenium Ion ◽  
Femtosecond Transient Absorption ◽  
Aqueous Conditions

Nitrenium ions are common reactive intermediates with high activities towards some biological nucleophiles. In this paper, we employed femtosecond transient absorption (fs-TA) and nanosecond transient absorption (ns-TA) as well as nanosecond time-resolved resonance Raman (ns-TR3) spectroscopy and density function theory (DFT) calculations to study the spectroscopic properties of the N(4,4′–dibromodiphenylamino)–2,4,6–trimethylpyridinium BF4− salt (1) in an acidic aqueous solution. Efficient cleavage of the N–N bond (4 ps) to form the N,N–di(4–bromophenyl)nitrenium ion (DN) was also observed in the acidic aqueous solution. As a result, the dication intermediate 4 appears more likely to be produced after abstracting a proton for the nitrenium ion DN in the acid solution first, followed by an electron abstraction to form the radical cation intermediate 3. These new and more extensive time-resolved spectroscopic data will be useful to help to develop an improved understanding of the identity, nature, and properties of nitrenium ions involved in reactions under acidic aqueous conditions.

Myeloperoxidase as a generator of drug free radicals

1995 ◽  
Vol 61 ◽  
pp. 163-170 ◽  
Author(s):  
Jack P. Uetrecht
Keyword(s):  
Neutrophil Function ◽  
Reactive Metabolites ◽  
Therapeutic Effects ◽  
Aminosalicylic Acid ◽  
Idiosyncratic Drug Reactions ◽  
Drug Reactions ◽  
Drug Induced ◽  
Nitrenium Ion ◽  
High Incidence ◽  
Inflammatory Bowel

Reactive metabolites are believed to be responsible for many types of toxicity, including idiosyncratic drug reactions. Bone marrow is a frequent target of idiosyncratic reactions, and, since these reactions have characteristics that suggest involvement of the immune system, the formation of reactive metabolites by leucocytes could also play a role in the aetiology of idiosyncratic drug reactions. The major oxidation system in neutrophils and monocytes is a combination of NADPH oxidase and myeloperoxidase. This system oxidizes primary arylamines, such as sulphonamides, to reactive metabolites and these drugs are also associated with a high incidence of agranulocytosis, generalized idiosyncratic reactions and/ or drug-induced lupus. Clozapine is oxidized by this system to a relatively stable nitrenium ion; clozapine is also associated with a high incidence of agranulocytosis. Arylamines that have an oxygen or nitrogen in the para position, such as amodiaquine, vesnarinone and 5-aminosalicylic acid, are oxidized to quinone-like reactive intermediates. Aminopyrine is oxidized to a very reactive dication. Such reactive metabolites could also inhibit neutrophil function and mediate some of the therapeutic effects of these drugs: for example, the use of dapsone for dermatitis herpetiformis and the use of 5-aminosalicylic acid for inflammatory bowel disease.

N-acetoxy-N-alkoxyamides - a new class of nitrenium ion precursors which are mutagenic

1989 ◽  
Vol 30 (20) ◽  
pp. 2649-2652 ◽  
Author(s):  
Robert G. Gerdes ◽  
Stephen A. Glover ◽  
José F. ten Have ◽  
Colleen A. Rowbottom
Keyword(s):  
Nitrenium Ion ◽  
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