Piotr J. Chmielewski

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Triindenotriphenylenes: Spin‐Frustrated Triskelion Triradicals with Excellent Ambient Stability

Arseni Borissov, Piotr J. Chmielewski, Abel Cárdenas Valdivia, Carlos J. Gómez García, more

Angewandte Chemie International Edition > 63 > 36 > n/a - n/a

A triskelion‐shaped triradical triindeno[1,2‐a:1′,2′‐g : 1′′,2′′‐m]triphenylen‐7‐yl (1) and its internally fused derivative (2) obtained by oxidative cyclization were prepared in a straightforward synthetic sequence. Both compounds were confirmed to be triradicals and to possess intramolecular antiferromagnetic exchange interactions between spins, displaying a spin‐frustrated doublet ground state...

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Triindenotriphenylenes: Spin‐Frustrated Triskelion Triradicals with Excellent Ambient Stability

Arseni Borissov, Piotr J. Chmielewski, Abel Cárdenas Valdivia, Carlos J. Gómez García, more

Angewandte Chemie > 136 > 36 > n/a - n/a

A triskelion‐shaped triradical triindeno[1,2‐a:1′,2′‐g : 1′′,2′′‐m]triphenylen‐7‐yl (1) and its internally fused derivative (2) obtained by oxidative cyclization were prepared in a straightforward synthetic sequence. Both compounds were confirmed to be triradicals and to possess intramolecular antiferromagnetic exchange interactions between spins, displaying a spin‐frustrated doublet ground state...

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Hierarchical Self‐Assembly of Curved Aromatics: From Donor–Acceptor Porphyrins to Triply Periodic Minimal Surfaces

Sunit Kumar, Tadeusz Lis, Wojciech Bury, Piotr J. Chmielewski, more

Angewandte Chemie > 136 > 9 > n/a - n/a

A saddle‐shaped π‐extended zinc porphyrin containing a peripheral pyridyl ligand undergoes quantitative self‐assembly into a cyclic trimer. The trimer has a prismatic structure with negatively curved side walls, which promote the formation of supramolecular organic frameworks stabilized by dispersion interactions. The first framework type, UWr‐1, has the npo topology, with a hexagonal structure analogous...

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Hierarchical Self‐Assembly of Curved Aromatics: From Donor–Acceptor Porphyrins to Triply Periodic Minimal Surfaces

Sunit Kumar, Tadeusz Lis, Wojciech Bury, Piotr J. Chmielewski, more

Angewandte Chemie International Edition > 63 > 9 > n/a - n/a

A saddle‐shaped π‐extended zinc porphyrin containing a peripheral pyridyl ligand undergoes quantitative self‐assembly into a cyclic trimer. The trimer has a prismatic structure with negatively curved side walls, which promote the formation of supramolecular organic frameworks stabilized by dispersion interactions. The first framework type, UWr‐1, has the npo topology, with a hexagonal structure analogous...

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π‐Extended Hexapyrrolylbenzenes: Exploring Charge‐Transfer Phenomena in Donor‐Acceptor Propellers

Daniel Matuszczyk, Yu Jin Lee, Seongsoo Kang, Piotr J. Chmielewski, more

Chemistry – A European Journal > 29 > 67 > n/a - n/a

A family of propeller‐shaped donor‐acceptor hexapyrrolylbenzenes (HPBs) were designed and synthesized by sequential nucleophilic substitution of hexafluorobenzene with π‐extended pyrroles. In particular, four hybrids were obtained, containing various combinations of electron‐rich and electron‐poor acenaphthylene‐fused pyrroles. Additionally, to probe the efficiency of ortho transfer interactions,...

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Dinor[7]helicene and Beyond: Divergent Synthesis of Chiral Diradicaloids with Variable Open‐Shell Character

Arseni Borissov, Piotr J. Chmielewski, Carlos J. Gómez García, Tadeusz Lis, more

Angewandte Chemie International Edition > 62 > 38 > n/a - n/a

Diradicaloid helicenes constructed formally by non‐benzenoid double π‐extension of phenanthrene were synthesized by a common strategy involving double electrophilic benzannulation. Steric effects in the second benzannulation step led to considerable structural diversity among the products, yielding a symmetrical dinor[7]helicene 1 and two isomeric unsymmetrical double helicenes 2 and 3, containing...

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Dinor[7]helicene and Beyond: Divergent Synthesis of Chiral Diradicaloids with Variable Open‐Shell Character

Arseni Borissov, Piotr J. Chmielewski, Carlos J. Gómez García, Tadeusz Lis, more

Angewandte Chemie > 135 > 38 > n/a - n/a

Diradicaloid helicenes constructed formally by non‐benzenoid double π‐extension of phenanthrene were synthesized by a common strategy involving double electrophilic benzannulation. Steric effects in the second benzannulation step led to considerable structural diversity among the products, yielding a symmetrical dinor[7]helicene 1 and two isomeric unsymmetrical double helicenes 2 and 3, containing...

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Tridecacyclene Tetraimide: An Easily Reduced Cyclooctatetraene Derivative

Rakesh Kumar, Piotr J. Chmielewski, Tadeusz Lis, Dirk Volkmer, more

Angewandte Chemie > 134 > 38 > n/a - n/a

Tridecacyclene tetraimide, TCTI, an electron‐deficient non‐benzenoid nanocarbon with a C₅₆N₄ polycyclic framework was obtained in a concise synthesis. TCTI has a non‐planar structure and forms π‐stacked dimers in the solid state. In solution, it undergoes eight single‐electron reductions, yielding a range of negatively charged states up to an octaanion. Except for the latter species, which has a remarkably...

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Tridecacyclene Tetraimide: An Easily Reduced Cyclooctatetraene Derivative

Rakesh Kumar, Piotr J. Chmielewski, Tadeusz Lis, Dirk Volkmer, more

Angewandte Chemie International Edition > 61 > 38 > n/a - n/a

Tridecacyclene tetraimide, TCTI, an electron‐deficient non‐benzenoid nanocarbon with a C₅₆N₄ polycyclic framework was obtained in a concise synthesis. TCTI has a non‐planar structure and forms π‐stacked dimers in the solid state. In solution, it undergoes eight single‐electron reductions, yielding a range of negatively charged states up to an octaanion. Except for the latter species, which has a remarkably...

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Helicity Modulation in NIR‐Absorbing Porphyrin‐Ryleneimides

Shivaprasad Achary Balahoju, Yogesh Kumar Maurya, Piotr J. Chmielewski, Tadeusz Lis, more

Angewandte Chemie > 134 > 18 > n/a - n/a

Peripheral substitution of a π‐extended porphyrin with bulky groups produces a curved chromophore with four helical stereogenic units. The curvature and stereochemistry of such porphyrins can be controlled by varying the substituents, coordinated metal ions, and apical ligands. In particular, when the achiral saddle‐shaped free bases are treated with large metal ions, i.e., Cd^II or Hg^II, the resulting...

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Helicity Modulation in NIR‐Absorbing Porphyrin‐Ryleneimides

Shivaprasad Achary Balahoju, Yogesh Kumar Maurya, Piotr J. Chmielewski, Tadeusz Lis, more

Angewandte Chemie International Edition > 61 > 18 > n/a - n/a

Peripheral substitution of a π‐extended porphyrin with bulky groups produces a curved chromophore with four helical stereogenic units. The curvature and stereochemistry of such porphyrins can be controlled by varying the substituents, coordinated metal ions, and apical ligands. In particular, when the achiral saddle‐shaped free bases are treated with large metal ions, i.e., Cd^II or Hg^II, the resulting...

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An Open‐Shell Coronoid with Hybrid Chichibabin–Schlenk Conjugation

Bibek Prajapati, Duy‐Khoi Dang, Piotr J. Chmielewski, Marcin A. Majewski, more

Angewandte Chemie International Edition > 60 > 41 > 22496 - 22504

A hexaradicaloid molecule with alternating Kekulé and non‐Kekulé connectivities between adjacent spin centers was obtained by fusing two conjugation motifs in Chichibabin and Schlenk hydrocarbons into a coronoid structure. ¹H NMR, ESR, and SQUID experiments and computational analyses show that the system has a singlet ground state with a significant hexaradicaloid character (γ₀=0.826, γ₁=γ₂=0.773)...

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An Open‐Shell Coronoid with Hybrid Chichibabin–Schlenk Conjugation

Bibek Prajapati, Duy‐Khoi Dang, Piotr J. Chmielewski, Marcin A. Majewski, more

Angewandte Chemie > 133 > 41 > 22670 - 22678

A hexaradicaloid molecule with alternating Kekulé and non‐Kekulé connectivities between adjacent spin centers was obtained by fusing two conjugation motifs in Chichibabin and Schlenk hydrocarbons into a coronoid structure. ¹H NMR, ESR, and SQUID experiments and computational analyses show that the system has a singlet ground state with a significant hexaradicaloid character (γ₀=0.826, γ₁=γ₂=0.773)...

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Conformation‐Dependent Response to the Protonation of Diphenanthrioctaphyrin(1.1.1.0.1.1.1.0): A Route to Pseudorotaxane‐Like Structures

Bartosz Szyszko, Monika Przewoźnik, Michał J. Białek, Agata Białońska, more

Chemistry – A European Journal > 26 > 39 > 8555 - 8566

Diphenanthrioctaphyrin(1.1.1.0.1.1.1.0), an expanded carbaporphyrinoid incorporating two phenanthrenylene moieties, exists as two separate, yet interconvertible, locked stereoisomers. These species demonstrate complex dynamic behavior upon protonation, consisting in multiple conformational rearrangements and anion‐binding events. The formation of one of the final dicationic forms is accompanied by...

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Cover Feature: Conformation‐Dependent Response to the Protonation of Diphenanthrioctaphyrin(1.1.1.0.1.1.1.0): A Route to Pseudorotaxane‐Like Structures (Chem. Eur. J. 39/2020)

Bartosz Szyszko, Monika Przewoźnik, Michał J. Białek, Agata Białońska, more

Chemistry – A European Journal > 26 > 39 > 8480 - 8480

The carbaporphyrinoid rollercoaster: Diphenanthrioctaphyrin(1.1.1.0.1.1.1.0) exists as two locked figure‐eight isomers that demonstrate multiple conformational rearrangements and anion‐binding events upon protonation. Formation of one of the final dications is accompanied by an inclusion of a complex anion within the cavity yielding a pseudorotaxane‐like complex. Multiple conformational transformations...

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Aromatic and Antiaromatic Pathways in Triphyrin(2.1.1) Annelated with Benzo[b]heterocycles

Krzysztof Bartkowski, Maria Dimitrova, Piotr J. Chmielewski, Dage Sundholm, more

Chemistry – A European Journal > 25 > 68 > 15477 - 15482

Understanding of the aromatic properties and magnetically induced current densities of highly conjugated chromophores is important when designing molecules with strongly delocalized electronic structure. Linear extension of the triphyrin(2.1.1) skeleton with an annelated benzo[b]heterocycle fragment modifies the aromatic character by extending the electron delocalization pathway. Two‐electron reduction...

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C−H and C−M Activation, Aromaticity Tuning, and Co⋅⋅⋅Ru Interactions Confined in the Azuliporphyrin Framework

Michał J. Białek, Piotr J. Chmielewski, Lechosław Latos‐Grażyński

Chemistry – A European Journal > 25 > 64 > 14479 - 14479

Invited for the cover of this issue is Lechosław Latos‐Grażyński and co‐workers at University of Wrocław. The image depicts cobalt(II) azuliporphyrin as a magical organometallic platform to perform other types of chemistry, that is, dioxygen activation, aromaticity control, and construction of intermetallic communication motifs. Read the full text of the article at 10.1002/chem.201903215.

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Front Cover: C−H and C−M Activation, Aromaticity Tuning, and Co⋅⋅⋅Ru Interactions Confined in the Azuliporphyrin Framework (Chem. Eur. J. 64/2019)

Michał J. Białek, Piotr J. Chmielewski, Lechosław Latos‐Grażyński

Chemistry – A European Journal > 25 > 64 > 14475 - 14475

An organometallic platform, azuliporphyrin, was used to explore Co^II and Cu^II reactivity. The activation of C(sp²)–H occurs with formation of a C−M^II bond. The metal center activates a dioxygen molecule that enables the oxygen atom insertion into the organometallic bond. During the formation of the diamagnetic cobalt complexes, the macrocycle aromaticity is enhanced. π‐Coordination of the azulene...

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C−H and C−M Activation, Aromaticity Tuning, and Co⋅⋅⋅Ru Interactions Confined in the Azuliporphyrin Framework

Michał J. Białek, Piotr J. Chmielewski, Lechosław Latos‐Grażyński

Chemistry – A European Journal > 25 > 64 > 14536 - 14545

Taking advantage of the specific properties of azuliporphyrin and the reactivity of cobalt(II), activation of an azulene C(sp²)−H bond occurred and organometallic complexes with Co−C bonding were formed. The system allowed for macrocyclic aromaticity tuning through metal coordination and oxidation. Thanks to the Co^II−C and parallel tested Cu^II−C reactivity and the affinity of metal centers to dioxygen,...

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Rücktitelbild: Stereocontrolled Synthesis of Chiral Heteroaromatic Propellers with Small Optical Bandgaps (Angew. Chem. 15/2019)

Maksim Navakouski, Halina Zhylitskaya, Piotr J. Chmielewski, Tadeusz Lis, more

Angewandte Chemie > 131 > 15 > 5190 - 5190

Ein einfaches Reagens , N‐Bromsuccinimid, ist das Oxidationsmittel der Wahl in der stereospezifischen Synthese von Azacoronen‐Propellern. Diese Familie chiraler Chromophore zeichnet sich durch kleine elektronische Bandlücken, eine vielseitige Redoxchemie und große chiroptische Signale aus, wie M. Stępień und Mitarbeiter in ihrer Zuschrift auf S. 4983 berichten.

INFONA - science communication portal

Search results for: Piotr J. Chmielewski

Triindenotriphenylenes: Spin‐Frustrated Triskelion Triradicals with Excellent Ambient Stability

Triindenotriphenylenes: Spin‐Frustrated Triskelion Triradicals with Excellent Ambient Stability

Hierarchical Self‐Assembly of Curved Aromatics: From Donor–Acceptor Porphyrins to Triply Periodic Minimal Surfaces

Hierarchical Self‐Assembly of Curved Aromatics: From Donor–Acceptor Porphyrins to Triply Periodic Minimal Surfaces

π‐Extended Hexapyrrolylbenzenes: Exploring Charge‐Transfer Phenomena in Donor‐Acceptor Propellers

Dinor[7]helicene and Beyond: Divergent Synthesis of Chiral Diradicaloids with Variable Open‐Shell Character

Dinor[7]helicene and Beyond: Divergent Synthesis of Chiral Diradicaloids with Variable Open‐Shell Character

Tridecacyclene Tetraimide: An Easily Reduced Cyclooctatetraene Derivative

Tridecacyclene Tetraimide: An Easily Reduced Cyclooctatetraene Derivative

Helicity Modulation in NIR‐Absorbing Porphyrin‐Ryleneimides

Helicity Modulation in NIR‐Absorbing Porphyrin‐Ryleneimides

An Open‐Shell Coronoid with Hybrid Chichibabin–Schlenk Conjugation

An Open‐Shell Coronoid with Hybrid Chichibabin–Schlenk Conjugation

Conformation‐Dependent Response to the Protonation of Diphenanthrioctaphyrin(1.1.1.0.1.1.1.0): A Route to Pseudorotaxane‐Like Structures

Cover Feature: Conformation‐Dependent Response to the Protonation of Diphenanthrioctaphyrin(1.1.1.0.1.1.1.0): A Route to Pseudorotaxane‐Like Structures (Chem. Eur. J. 39/2020)

Aromatic and Antiaromatic Pathways in Triphyrin(2.1.1) Annelated with Benzo[b]heterocycles

C−H and C−M Activation, Aromaticity Tuning, and Co⋅⋅⋅Ru Interactions Confined in the Azuliporphyrin Framework

Front Cover: C−H and C−M Activation, Aromaticity Tuning, and Co⋅⋅⋅Ru Interactions Confined in the Azuliporphyrin Framework (Chem. Eur. J. 64/2019)

C−H and C−M Activation, Aromaticity Tuning, and Co⋅⋅⋅Ru Interactions Confined in the Azuliporphyrin Framework

Rücktitelbild: Stereocontrolled Synthesis of Chiral Heteroaromatic Propellers with Small Optical Bandgaps (Angew. Chem. 15/2019)

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