scholarly journals Sustainable Approaches to the Synthesis of Metallophthalocyanines in Solution

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1760
Author(s):  
Gloria Zanotti ◽  
Patrizia Imperatori ◽  
Anna Maria Paoletti ◽  
Giovanna Pennesi
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Potassium Hydroxide ◽  
Production Cost ◽  
Added Value ◽  
Reaction Conditions ◽  
Transition Metal Cations ◽  
Tert Butyl ◽  
Whole Process ◽  
Reaction Media

This work aims to investigate more sustainable reaction conditions for the synthesis of metallophthalocyanines. Anisole, glycerol and their mixtures have been investigated as reaction media for the tetramerization of phthalonitriles. Acetates of three divalent first-transition metal cations, Co(II), Cu(II) and Zn(II), were used and several bases were tested, depending on the chosen substrates and reaction conditions, with a view to making the whole process more sustainable while ensuring its scalability. Unsubstituted phthalocyanines were synthesized to analyze the behavior of the different metal ions in terms of reactivity in the new reaction media, resulting in a general Cu > Co > Zn trend, while the nonpolar tetra-tert-butyl substitution was investigated to evaluate the synthesis of soluble derivatives in the new conditions. Furthermore, the potassium hydroxide (KOH)-aided statistical synthesis of the unsymmetrical 9(10), 16(17), 23(24)-tri-tert-butyl-2-iodophthalocyaninato zinc(II), starting from 4-tert-butylphthalonitrile and 4-iodophthalonitrile in a glycerol/anisole mixture, proceeded with a satisfactory 26% yield. Our results provide insights into the investigation of new reaction environments and the understanding of their strengths and weaknesses, with a view to further increasing the sustainability of the synthesis of metallomacrocycles with high added value while lowering their production cost.

New cobalt(ii) coordination designs and the influence of varying chelate characters, ligand charges and incorporated group I metal ions on enzyme-like oxidative coupling activity

2020 ◽  
Vol 44 (35) ◽  
pp. 14849-14858
Author(s):  
Hammed Olawale Oloyede ◽  
Joseph Anthony Orighomisan Woods ◽  
Helmar Görls ◽  
Winfried Plass ◽  
Abiodun Omokehinde Eseola
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Active Site ◽  
Oxidative Coupling ◽  
Reaction Conditions ◽  
Group I ◽  
Mediated Catalysis

In transition-metal-mediated catalysis, design of new, well defined coordination architectures and subjecting them to catalysis testing under the same reaction conditions is a necessity tool for improved understanding of desirable active site geometries and characteristics.

scholarly journals Redox Active Transition Metal ions Make Melanin Susceptible to Chemical Degradation Induced by Organic Peroxide

2017 ◽  
Vol 75 (3-4) ◽  
pp. 319-333 ◽  
Author(s):  
Andrzej Zadlo ◽  
Anna Pilat ◽  
Michal Sarna ◽  
Anna Pawlak ◽  
Tadeusz Sarna
Keyword(s):  
Retinal Pigment Epithelium ◽  
Transition Metal ◽  
Metal Ions ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Transition Metal Ions ◽  
Chemical Degradation ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide

Abstract With aging, retinal pigment epithelium melanosomes, by fusion with the age pigment lipofuscin, form complex granules called melanolipofuscin. Lipofuscin granules may contain oxidized proteins and lipid hydroperoxides, which in melanolipofuscin could chemically modify melanin polymer, while transition metal ions present in melanin can accelerate such oxidative modifications. The aim of this research was to examine the effect of selected transition metal ions on melanin susceptibility to chemical modification induced by the water-soluble tert-butyl hydroperoxide used as an oxidizing agent. Synthetic melanin obtained by DOPA autooxidation and melanosomes isolated from bovine retinal pigment epithelium were analyzed. To monitor tert-butyl hydroperoxide-induced oxidative changes of DMa and BMs, electron paramagnetic resonance spectroscopy, UV-vis absorption spectroscopy, dynamic light scattering, atomic force microscopy and electron paramagnetic resonance oximetry were employed. These measurements revealed that both copper and iron ions accelerated chemical degradation induced by tert-butyl hydroperoxide, while zinc ions had no effect. Strong prooxidant action was detected only in the case of melanosomes and melanin degraded in the presence of iron. It can be postulated that similar chemical processes, if they occur in situ in melanolipofuscin granules of the human retinal pigment epithelium, would modify antioxidant properties of melanin and its reactivity.

scholarly journals Highly selective synthesis of citronellal in water at multigram scale by Pd nanoparticles-catalyzed hydrogenation of citral

2021 ◽  
Author(s):  
DUVAL Marion ◽  
SAGORIN Gilles ◽  
Audrey Denicourt-Nowicki ◽  
Alain ROUCOUX
Keyword(s):  
Double Bond ◽  
Palladium Nanoparticles ◽  
Potassium Hydroxide ◽  
Pd Nanoparticles ◽  
Added Value ◽  
Selective Synthesis ◽  
Complete Conversion ◽  
Turnover Number ◽  
Reaction Conditions ◽  
Excellent Selectivity

The synthesis of citronellal, an added-value chemical for perfumery, was carried out by selective and green hydrogenation of citral into citronellal in water. Aqueous suspensions of spherical ammonium-capped palladium nanoparticles with sizes around 3nm selectively reduced the conjugated carbon-carbon double bond. An excellent selectivity of 95% in citronellal was achieved at complete conversion under mild reaction conditions on a realistic 2 g scale in water. The presence of potassium hydroxide proved crucial to control the selectivity and avoid other hydrogenation co-products. These optimized results were further extended to a 135 g substrate loading with a relevant turnover number (TON) of 10 000.

scholarly journals Pb2+ Selectivity of Two New Mono Pyrene Acetamide Calix[4]arenes

2016 ◽  
Vol 11 (7) ◽  
pp. 3772-3776
Author(s):  
Lassaad Baklouti ◽  
Rahma Aroua ◽  
Slim Mannai ◽  
Michael J. Chetcuti ◽  
Abdelwaheb Hamdi
Keyword(s):  
Transition Metal ◽  
Butyl Ester ◽  
Metal Cations ◽  
Fluorescence Study ◽  
Transition Metal Cations ◽  
Binding Properties ◽  
Tert Butyl

The synthesis of a new mono tert-butyl ester mono pyrene acetamide calix[4]arene 2 and 5,11,17,23-tetra(tert-butyl)-25-pyrene acetamide-27-acid calix[4]arene 3, that both present pyrene fluorescent functionalities is reported. The binding properties towards a variety of transition and non-transition metal cations have been determined along with a fluorescence study. Particular selectivity to lead cations was observed

scholarly journals A Convenient Synthesis of Thiol, Trithiocarbonate and Disulfide

2021 ◽  
Author(s):  
Sudershan Reddy Gondi ◽  
Christiana Julia Rissing ◽  
David Y. Son
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Sodium Salt ◽  
Phase Transfer ◽  
Raft Polymerization ◽  
Transition Metal Ions ◽  
Phase Transfer Catalyst ◽  
Reaction Conditions ◽  
Convenient Synthesis

<div>Synthesis of unsymmetrical trithiocarbonate sulfonate salt, along with disulfide, thiol and</div><div>symmetrical trithiocarbonate from 3-mercapto-1-propane-sulfonicacid, sodium salt with, without</div><div>of phase transfer catalyst and under various reaction conditions are described. The obtained</div><div>compounds having divergent usefulness in RAFT polymerization, sulfonyl preparation and</div><div>having capable of binding in a multidentate fashion to soft transition metal ions.</div>

Structural snapshots of the rearrangement of the bis(di-tert-butyl-aminophenyl)amine pincer ligand in the presence of transition metal ions

2018 ◽  
Vol 47 (33) ◽  
pp. 11303-11307 ◽  
Author(s):  
N. Leconte ◽  
B. Baptiste ◽  
C. Philouze ◽  
F. Thomas
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Pincer Ligand ◽  
Tert Butyl ◽  
Redox Active ◽  
Active Transition

The ligand undergoes N–N and C–N bond formations in the presence of redox-active transition metal ions, in air and coordinating solvents.

scholarly journals A Convenient Synthesis of Thiol, Trithiocarbonate and Disulfide

2021 ◽  
Author(s):  
Sudershan Reddy Gondi ◽  
Christiana Julia Rissing ◽  
David Y. Son
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Sodium Salt ◽  
Phase Transfer ◽  
Raft Polymerization ◽  
Transition Metal Ions ◽  
Phase Transfer Catalyst ◽  
Reaction Conditions ◽  
Convenient Synthesis

<div>Synthesis of unsymmetrical trithiocarbonate sulfonate salt, along with disulfide, thiol and</div><div>symmetrical trithiocarbonate from 3-mercapto-1-propane-sulfonicacid, sodium salt with, without</div><div>of phase transfer catalyst and under various reaction conditions are described. The obtained</div><div>compounds having divergent usefulness in RAFT polymerization, sulfonyl preparation and</div><div>having capable of binding in a multidentate fashion to soft transition metal ions.</div>

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