Pol-KT Lab Publications – Kimika Teorikoa

@article{Pagnacco2024,

title = {Zwitterionic ring expansion polymerization of \textit{tert}‐butyl glycidyl ether with B(C_{6}F_{5})_{3} towards the generation of cyclic chains},

author = {Carlo Andrea Pagnacco and Xuban Gastearena and Estibaliz González de San Román and Jon M. Matxain and Fabienne Barroso‐Bujans},

doi = {10.1002/pol.20240112},

issn = {2642-4169},

year  = {2024},

date = {2024-06-15},

journal = {Journal of Polymer Science},

volume = {62},

number = {12},

pages = {2704--2715},

publisher = {Wiley},

abstract = {AbstractThe synthesis of cyclic polymers via zwitterionic ring expansion polymerization is limited to a few number of monomer and catalyst pairs. Herein we report the synthesis of cyclic poly(tert‐butyl glycidyl ether) through the polymerization of tert‐butyl glycidyl ether (tBGE) with B(C6F5)3 in different reaction conditions that include different solvents, monomer to initiator ratio, monomer concentration and temperature. We found that bimodal molecular weight distribution is formed in almost all reaction conditions caused by cyclization of short chains. Subsequent chain elongation leads to the formation of cycles of higher molecular weight, particularly in cyclohexane and under bulk conditions. The formation of non‐cyclic byproducts is common in all the systems investigated. Low molecular weight cyclic chains (Mn = 0.7 kDa, Ð = 1.1) of high topological purity were successfully isolated by preparative gel permeation chromatography. By using a click scavenging protocol, the non‐cyclic byproducts were eliminated from the high molecular weight fraction (Mn = 3 kDa, Ð = 1.3) generating pure cyclic chains. Mechanistic investigation using density functional theory calculations was performed on the formation of zwitterionic intermediates and the transfer reaction to the monomer, which notably affects chain growth by the attack of the glycidyl oxygen of the monomer on the growing chain.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

115.

Izu, Asier E.; Matxain, Jon M.; Casanova, David

Reverse intersystem crossing mechanisms in doped triangulenes Journal Article

Phys. Chem. Chem. Phys., 2024, 26(15), 11459--11468

Abstract | Links | BibTeX

114.

Nakahata, Douglas H.; Kanavos, Ioannis; Zubiria‐Ulacia, Maria; Inague, Alex; Salassa, Luca; Lobinski, Ryszard; Miyamoto, Sayuri; Matxain, Jon Mattin; Ronga, Luisa; de Paiva, Raphael E. F.

Gold‐Promoted Biocompatible Selenium Arylation of Small Molecules, Peptides and Proteins Journal Article

Chemistry A European J, 2024, 30(15)

Abstract | Links | BibTeX

@article{Nakahata2024,

title = {Gold‐Promoted Biocompatible Selenium Arylation of Small Molecules, Peptides and Proteins},

author = {Douglas H. Nakahata and Ioannis Kanavos and Maria Zubiria‐Ulacia and Alex Inague and Luca Salassa and Ryszard Lobinski and Sayuri Miyamoto and Jon Mattin Matxain and Luisa Ronga and Raphael E. F. de Paiva},

doi = {10.1002/chem.202304050},

issn = {1521-3765},

year  = {2024},

date = {2024-03-12},

journal = {Chemistry A European J},

volume = {30},

number = {15},

publisher = {Wiley},

abstract = {AbstractA low pKa (5.2), high polarizable volume (3.8 Å), and proneness to oxidation under ambient conditions make selenocysteine (Sec, U) a unique, natural reactive handle present in most organisms across all domains of life. Sec modification still has untapped potential for site‐selective protein modification and probing. Herein we demonstrate the use of a cyclometalated gold(III) compound, [Au(bnpy)Cl2], in the arylation of diselenides of biological significance, with a scope covering small molecule models, peptides, and proteins using a combination of multinuclear NMR (including 77Se NMR), and LC–MS. Diphenyl diselenide (Ph−Se)2 and selenocystine, (Sec)2, were used for reaction optimization. This approach allowed us to demonstrate that an excess of diselenide (Au/Se−Se) and an increasing water percentage in the reaction media enhance both the conversion and kinetics of the C−Se coupling reaction, a combination that makes the reaction biocompatible. The C−Se coupling reaction was also shown to happen for the diselenide analogue of the cyclic peptide vasopressin ((Se−Se)‐AVP), and the Bos taurus glutathione peroxidase (GPx1) enzyme in ammonium acetate (2 mM, pH=7.0). The reaction mechanism, studied by DFT revealed a redox‐based mechanism where the C−Se coupling is enabled by the reductive elimination of the cyclometalated Au(III) species into Au(I).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}