Publications by Andrzej Sienkiewicz

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

Andrzej Sienkiewicz, Rosario Scopelliti, Marinella Mazzanti, 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, Andrzej Sienkiewicz, Claudio Grimaldi, Endre Horvath

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

Andrzej Sienkiewicz, Rosario Scopelliti, Marinella Mazzanti

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?

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

ELSEVIER SCIENCE INC2023

Isolation and redox reactivity of cerium complexes in four redox states

Andrzej Sienkiewicz, Rosario Scopelliti, Marinella Mazzanti, 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

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

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

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

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

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

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

Andrzej Sienkiewicz, Marinella Mazzanti, Ivica Zivkovic, Farzaneh Fadaei Tirani, 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

Central nervous system and systemic oxidative stress interplay with inflammation in a bile duct ligation rat model of type C hepatic encephalopathy (vol 178, pg 295, 2022)

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

ELSEVIER SCIENCE INC2022

Assembling diuranium complexes in different states of charge with a bridging redox-active ligand

Andrzej Sienkiewicz, Rosario Scopelliti, Marinella Mazzanti, Ivica Zivkovic, Dieuwertje Katelijn Modder

Radical-bridged diuranium complexes are desirable for their potential high exchange coupling and single molecule magnet (SMM) behavior, but remain rare. Here we report for the first time radical-bridged diuranium(IV) and diuranium(III) complexes. Reaction ...

ROYAL SOC CHEMISTRY2022

Cation assisted binding and cleavage of dinitrogen by uranium complexes

Andrzej Sienkiewicz, Rosario Scopelliti, Marinella Mazzanti, Ivica Zivkovic, Nadir Jori

The role of alkali promoters in N-2 cleavage by metal complexes remains poorly understood despite its relevance to the industrial production of ammonia from N-2. Here we report a series of alkali bound-oxo-bridged diuranium(iii) complexes that provide a un ...

ROYAL SOC CHEMISTRY2022

Decrypting the photocatalytic bacterial inactivation of hierarchical flower-like Bi(2)WO6 microspheres induced by surface properties: Experimental studies and ab initio calculations

César Pulgarin, Andrzej Sienkiewicz

Bi2WO6 is considered an effective photocatalyst, even under the visible part of the solar spectrum, and recent advances in the modification of its structure leave promise for harnessing its enhanced effectiveness. Our experimental E. coli disinfection resu ...

ELSEVIER SCIENCE SA2022

Ultralong Charge Carrier Recombination Time in Methylammonium Lead Halide Perovskites

László Forró, Andrzej Sienkiewicz, Márton Kollár, Ferenc Simon

Due to their exceptional photovoltaic properties, metal halide perovskites (MHPs) are extensively studied for their potential applications in solar cells. In recent years, the power conversion efficiencies of MHPs-based solar cells rapidly increased from t ...

2022

Tuning the π‐Accepting Properties of Mesoionic Carbenes: A Combined Computational and Experimental Study

Andrzej Sienkiewicz, Kay Severin, Rosario Scopelliti, Anne-Clémence Corminboeuf, Farzaneh Fadaei Tirani, Jacob Terence Blaskovits, Zhaowen Dong

Mesoionic imidazolylidenes are recognized as excellent electron-donating ligands in organometallic and main group chemistry. However, these carbene ligands typically show poor π-accepting properties. We have performed a computational analysis of 71 mesoion ...

2021

High-Pressure Synthesis of Rare-Earth Borate-Nitrate Crystals for Second Harmonic Generation

László Forró, Andrzej Sienkiewicz, Alla Arakcheeva, Sergiy Katrych, Trpimir Ivsic

The crystals of a novel family of rare-earth borate-nitrate compounds, Ln(7)(BO3)(3) (NO3)N3O (Ln = Pr, Nd), were grown at high-pressure in KAs flux and their crystal structure was determined. The new type of the crystalline structure consists of parallel ...

AMER CHEMICAL SOC2021

Hybrid halide perovskite neutron detectors

László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Endre Horvath, Pavel Frajtag, Andreas Pautz, Pavao Roko Andricevic, Márton Kollár

Interest in fast and easy detection of high-energy radiation (x-, gamma-rays and neutrons) is closely related to numerous practical applications ranging from biomedicine and industry to homeland security issues. In this regard, crystals of hybrid halide pe ...

Nature Portfolio2021

Chromophore of an Enhanced Green Fluorescent Protein Can Play a Photoprotective Role Due to Photobleaching

László Forró, Andrzej Sienkiewicz, Katarzyna Pierzchala

Under stress conditions, elevated levels of cellular reactive oxygen species (ROS) may impair crucial cellular structures. To counteract the resulting oxidative damage, living cells are equipped with several defense mechanisms, including photoprotective fu ...

MDPI2021

Light-induced charge transfer at the CH3NH3PbI3/TiO2 interface-a low-temperature photo-electron paramagnetic resonance assay

Philippe Bugnon, László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Endre Horvath, Péter Szirmai, Pavao Roko Andricevic, Anastasiia Glushkova, Márton Kollár, Konstantins Mantulnikovs

The performance of organic-inorganic metal halide perovskites-based (MHPs) photovoltaic devices critically depends on the design and material properties of the interface between the light-harvesting MHP layer and the electron transport layer (ETL). Therefo ...

2020