Publications de Andrzej Sienkiewicz

Facile N-C bond cleavage and arene reduction by a transient uranium(ii) complex

Rosario Scopelliti, Marinella Mazzanti, Andrzej Sienkiewicz, Ivica Zivkovic

Complexes of uranium(ii) remain extremely rare and their reactivity is practically unexplored. Here we report that the reduction of the heteroleptic bis-aryloxide U(iii) complex [U(κ6-{(tBu2ArO)2Me2-cyclam})I], A, yields a rare and highly reactive U(ii) in ...

2025

Tuning the color of high-karat gold in Au-TiO2 nanoparticle composites all the way to black

László Forró, Claudio Grimaldi, Endre Horvath, Andrzej Sienkiewicz

For centuries, artisans have harnessed gold nanoparticles to imbue their creations with the vibrant hues that captivate the eye through interactions with visible light. In modern times, these distinct optoelectronic characteristics have pivoted toward the ...

Cell Press2024

Multielectron Redox Chemistry of Ytterbium Complexes Reaching the +1 and Zero Formal Oxidation States

Rosario Scopelliti, Marinella Mazzanti, Andrzej Sienkiewicz

Lanthanide redox reactivity remains limited to one-electron transfer reactions due to their inability to access a broad range of oxidation states. Here, we show that multielectron reductive chemistry is achieved for ytterbium by using the tripodal tris(sil ...

2024

Central Nervous System Oxidative Stress interplay with inflammation in a rat model of Type C Hepatic Encephalopathy - brothers in arms?

Cristina Ramona Cudalbu, Andrzej Sienkiewicz, Katarzyna Pierzchala, Dunja Simicic, Stefanita-Octavian Mitrea

ELSEVIER SCIENCE INC2023

Isolation and redox reactivity of cerium complexes in four redox states

Rosario Scopelliti, Marinella Mazzanti, Andrzej Sienkiewicz, Fang-Che Hsueh

The chemistry of lanthanides is limited to one electron transfer reactions due to the difficulty of accessing multiple oxidation states. Here we report that a redox-active ligand combining three siloxides with an arene ring in a tripodal ligand can stabili ...

2023

Head‐to‐Tail Dimerization of N‐Heterocyclic Diazoolefins

Rosario Scopelliti, Kay Severin, Farzaneh Fadaei Tirani, Andrzej Sienkiewicz, Tak Hin Wong, Zhaowen Dong, Paul Varava, Anastasia Gitlina, Wolfram Feuerstein

The head-to-tail dimerization of N-heterocyclic diazoolefins is described. The products of these formal (3+3) cycloaddition reactions are strongly reducing quinoidal tetrazines. Oxidation of the tetrazines occurs in a stepwise fashion, and we were able to ...

Wiley-VCH Verlag GmbH2023

A Mesoionic Diselenolene Anion and the Corresponding Radical Dianion

Rosario Scopelliti, Kay Severin, Farzaneh Fadaei Tirani, Andrzej Sienkiewicz, Cesare Berton, Abdusalom Suleymanov, Zhaowen Dong

Dichalcogenolenes are archetypal redox non-innocent ligands with numerous applications. Herein, we describe a diselenolene ligand with fundamentally different electronic properties. By selenation of a C2-protected imidazolium salt, we have prepared a mesoi ...

2022

Central nervous system and systemic oxidative stress interplay with inflammation in a bile duct ligation rat model of type C hepatic encephalopathy

Rolf Gruetter, Cristina Ramona Cudalbu, Andrzej Sienkiewicz, Katarzyna Pierzchala, Dunja Simicic, Stefanita-Octavian Mitrea

The role and coexistence of oxidative stress (OS) and inflammation in type C hepatic encephalopathy (C HE) is a subject of intense debate. Under normal conditions the physiological levels of intracellular reactive oxygen species are controlled by the count ...

2022

Solar water purification with photocatalytic nanocomposite filter based on TiO2 nanowires and carbon nanotubes

László Forró, Luca Rossi, Andrzej Sienkiewicz, Endre Horvath, Florian Frédéric Vincent Breider, Dominique Grandjean, Miriam Gaál

Water contamination due to environmental conditions and poor waste management in certain areas of the world represents a serious problem in accessing clean and safe drinking water. This problem is especially critical in electricity-poor regions, where adva ...

2022

Structure and Reactivity of Polynuclear Divalent Lanthanide Disiloxanediolate Complexes br

Marinella Mazzanti, Farzaneh Fadaei Tirani, Andrzej Sienkiewicz, Ivica Zivkovic, Aurélien René Willauer

Trinuclear molecular complexes of europium (II)and ytterbium(II) [Ln3{(Ph2SiO)2O}3(THF)6],1-Ln3L3(Ln = Euand Yb), supported by the dianionic tetraphenyl disiloxanediolateligand, were synthesized via protonolysis of the [Ln{N-(SiMe3)2}2(THF)2] complexes. In ...

2022