Dmitrii Perepichka

McGill University | McGill · Department of Chemistry

Two-dimensional (2D) π-conjugated polymers are promising electronic materials with diverse properties controlled by varying the structure of organic building blocks. We here report an organic framework with perchlorotriphenylmethyl (PTM) radical nodes, synthesized through dehalogenative thermolysis polymerization of tris(iodotetrachlorophenyl)metha...

This is the first review paper focusing on acenaphthylene (AN), an important building block of many organic semiconductors. We summarize the most important literature on π-conjugated AN derivatives, both small molecules and polymers, highlighting the synthetic approach and notable chemical modifications used in design of organic electronic material...

The direct polymerization via irreversible C-C coupling on inert substrates will give access to new low-dimensional advanced functional materials and simplify their industrial fabrication. In this work, we present our initial results in the application of Glaser coupling to the direct on-surface polymerization of a model diacetylene compound at the...

In organic compounds, room temperature phosphorescence (RTP) is a rare, yet highly desirable, property that is important for a wide variety of applications, including tissue imaging, anticounterfeiting technologies, photodynamic therapy, and organic light-emitting devices. While most organic RTP molecules rely on heavy atoms or carbonyl functional...

Herein, we elucidate the photodegradation pathway of A‐D‐A‐type non‐fullerene acceptors for organic photovoltaics. Using IT‐4F as a benchmark example, we isolated the photoproducts and proved them isomers of IT‐4F formed by a 6‐e electrocyclic reaction between the dicyanomethylene unit and the thiophene ring, followed by a 1,5‐sigmatropic hydride s...

In this work, we elucidate the photodegradation pathway of A-D-A type nonfullerene acceptors for organic photovoltaics. Using IT-4F as a benchmark example, we isolated the photoproducts and proved them isomers of IT-4F formed via a 6-e electrocyclic reaction between the dicyanomethylene unit and the thiophene ring, followed by a 1,5-sigmatropic hyd...

The discovery of organic metals in the 1970s opened the door to the design of electrical devices based on traditionally inert (insulating) organic materials. More recently, demonstration of record-high charge mobility and unusual electronic structure (e.g. Dirac cones) in graphene have given rise to an entire new field of two-dimensional (2D) mater...

On‐surface Ullmann coupling is an established method for the synthesis of 1D and 2D organic structures. A key limitation to obtaining ordered polymers is the uncertainty in the final structure for coupling via random diffusion of reactants over the substrate, which leads to polymorphism and defects. Here, a topotactic polymerization on Cu(110) in a...

In this work, we elucidate the photodegradation pathway of IT-4F, a benchmark A-D-A type semiconductor for organic photovoltaics. The photoproducts were isolated and shown to be isomers of IT-4F formed via a 6-e electrocyclic reaction between the dicyanomethylene unit and the thiophene ring, followed by a 1,5-sigmatropic hydride shift. Importantly,...

In this work, we elucidate the photodegradation pathway of IT-4F, a benchmark A-D-A type semiconductor for organic photovoltaics. The photoproducts were isolated and shown to be isomers of IT-4F formed via a 6-e electrocyclic reaction between the dicyanomethylene unit and the thiophene ring, followed by a 1,5-sigmatropic hydride shift. Importantly,...

Boroxine and dioxaborole are the first and some of the most studied synthons of Covalent Organic Frameworks (COFs). Despite their wide application in the design of functional COFs over the last 15 years, their synthesis still relies on the original Yaghi’s condensation of boronic acids (with itself or with polyfunctional catechols), some of which a...

Molecular doping has emerged as a powerful strategy to tune the charge transport properties of organic field-effect transistors (OFETs). However, the limited tool-box of molecular dopants and unresolved challenges of stability, uniformity of the doping, and matching the energy levels constrain the achieved OFET device performance and thwart the pra...

We report a comparative study of two structurally similar donor-acceptor complexes with (1a) and without (2a) H-bonding using X-ray crystallography, spectroscopic analysis, and density functional theory calculations. H-Bonding enhances the donor-acceptor interactions, as manifested in a narrower band gap and shorter π-stacking distance in 1a versus...

Exploring multifunctional, miniaturized light‐emitting devices with well‐controlled operation is deemed vital to meet the increasing demands of full‐color displays and lighting systems. Nevertheless, complicated architectures, low performance, and poor operational control remain daunting challenges in the realization of smart devices. Here, an alte...

We report a series of new halogenated bis(acenaphthylene)dione (BAN) derivatives and study the effect of their solid-state organization on optoelectronic properties and electron transport measured in n-type organic field-effect transistors...

Qichun Zhang, Dmitrii F. Perepichka, Hong Meng and Yongsheng Chen introduce the Materials Chemistry Frontiers themed issue celebrating Professor Fred Wudl's 80th birthday.

Planarity is essential for many organic electronic materials as it maximizes the intramolecular π‐orbital overlap and enables efficient intermolecular interactions through π‐stacking. We propose a statistical way of quantifying the planarity of a wide range of conjugated systems. The quantification takes into account all torsional conformations and...

A statistical way of quantifying the planarity of a wide range of conjugated systems is presented. The quantification takes into account all torsional conformations and their relative contribution to the overall structural disorder. The application of the analysis to extended conjugated systems and the correlations between the gas‐phase planarity i...

We report a detailed investigation of a series of new charge-transfer (CT) complexes assembled via a two-point complementary hydrogen bonding (H-bonding) of diindolopyrrole (DIP) electron donors with o-quinone and diazafluorenone acceptors. Unidirectional polarization through the DD⋯AA type H-bonding leads to a dramatic perturbation of electronic l...

Red luminescence is found in off‐white tris(iodoperchlorophenyl)methane (3I‐PTMH) crystals which is characterized by a high photoluminescence quantum yield (PLQY 91 %) and color purity (CIE coordinates 0.66, 0.34). The emission originates from the doublet excited state of the neutral radical 3I‐PTMR, which is spontaneously formed and becomes embedd...

Red luminescence in off‐white tris(iodoperchlorophenyl)methane crystals is characterized by a high quantum yield (PLQY 91 %) and color purity. The emission originates from the doublet excited state of the neutral radical defect. TD‐DFT calculations demonstrate that electron‐donating iodine atoms accelerate the radiative transition while the rigid h...

In article number 2000226 Majid Rasool, George P. Demopoulos, and co‐workers report the fabrication of a robust core‐shell lithium iron silicate (Li2FeSiO4, LFS) cathode architecture, where nanocrystal's core is prepared via mechanochemical annealing and shell via PEDOT polymerization. As a result of the devised mechanochemical/interphasial enginee...

Aromatically fluorinated polymers, which have been widely used in highly efficient polymer solar cells (PSCs), suffer from complicated synthesis and low yields. Herein, through replacing methyl group with trifluoromethyl group, the feasibility of synthetically-simple non-aromatic fluorination towards high-performance polymer donors is demonstrated....

Molecular packing of organic luminogens governs their photophysical behavior. In their Communication (DOI: 10.1002/anie.201913393), E. Hamzehpoor and D. F. Perepichka report a series of highly emissive azatriangulenetrione (TANGO) solids whose luminescent properties are controlled by the size of substituents. The co‐alignment of carbonyl groups in...

Die Molekülpackung bestimmt das photophysikalische Verhalten organischer Luminogene. In ihrer Zuschrift (DOI: 10.1002/ange.201913393) berichten E. Hamzehpoor und D. F. Perepichka über eine Serie von Azatriangulentrionen (TANGO), deren Lumineszenzeigenschaften von der Größe der Substituenten abhängen. Die gleiche Ausrichtung der Carbonylgruppen in s...

Lithium iron silicate (LFS) attracts a lot of attention due to its 330 mAh g−1 theoretical capacity (2 Li+ per formula unit). However, inherently it exhibits poor Li‐ion intercalation kinetics, interfacial reactivity, and complex phase transitions resulting in lower than one Li+ capacity and poor retention. In this work, a core–shell architecture i...

High quantum yield luminescent organic solids are required for a number of optoelectronic applications, including organic light-emitting diodes (OLEDs) and transistors (OLETs), lasers, etc. The absolute majority of organic materials can only emit efficiently from their singlet excited states. Involving high-multiplicity states (such as triplets) in...

Nitro group (NO2) is one of the most common electron-withdrawing groups but it has rarely been used in the design of organic semiconductors (OSCs). Herein, we report n-type semiconducting behavior of simple fluorenone derivatives functionalized with NO2 and CN groups. While the electron mobilities measured in thin film field-effect transistors are...

The nitro group (NO2) is one of the most common electron-withdrawing groups but it has rarely been used in the design of organic semiconductors (OSCs). Herein, we report the n-type semiconducting behavior of simple fluorenone derivatives functionalized with NO2 and CN groups. While the electron mobilities measured in the thin film field-effect tran...

We report the first transformation between crystalline vinylene-linked two-dimensional (2D) polymers and crystalline cyclobutane-linked three-dimensional (3D) polymers. Specifically, absorption-edge irradiation of the 2D poly(arylenevinylene) covalent organic frameworks (COFs) results in topological [2+2] cycloaddition cross-linking the π-stacked l...

Perovskite light-emitting diodes (PeLEDs) exhibit high external quantum efficiencies (EQEs), emerging as a next-generation lighting and display technology. Nevertheless, they suffer from severe efficiency roll-off at high luminance, particularly in the case of blue and green emissions, which is one of the major bottlenecks in their industrial appli...

We report the serendipitous discovery and synthesis of an indigoid “Semi-Nindigo” (2) via oxidation of a diindolopyrrole (1). Reaction of 2 with BF3Et2O affords the borylated derivate (3). The electronic spectra of 2 and 3 possess intense long wave absorptions near 600 nm and 650 nm. 3 is weakly emissive in the near-infrared. Thin film OFETs fabric...

Two-dimensional (2D) nanomaterials, such as graphene and single layer covalent organic frameworks (sCOFs) are being widely studied due to their unusual structure/property relationships. sCOFs typically feature atomic thickness, intrinsic nanoscale porosity and a crystalline lattice. Compared to other organic 2D materials, sCOFs exhibit major advant...

We report the first transformation between crystalline vinylene-linked two-dimensional (2D) polymers and crystalline cyclobutane-linked three-dimensional (3D) polymers. Specifically, absorption-edge irradiation of the 2D poly(arylenevinylene) covalent organic frameworks (COFs) results in topological [2+2] cycloaddition cross-linking the π-stacked l...

Herein, we report a new molecule structure modification strategy for non-fullerene small molecule electron acceptors (NFAs) for solar cells through trifluoromethylation of end-capping groups. The synthesized trifluoromethylated acceptor ITCF3 exhibits narrower band gap, stronger light absorption, lower molecular energy levels and better electron tr...

Surface-confined synthesis is a promising approach to build complex molecular nanostructures including macrocycles. However, despite the recent advances in on-surface macrocyclization under ultrahigh vacuum, selective synthesis of monodisperse and multicomponent macrocycles remains a challenge. Here, we report on an on-surface formation of [6 + 6]...

The black crystalline (aza)triangulene-based covalent organic framework (TANG-COF) was synthesized from trinitro-TANG precursor via one-pot-two-step reaction involving Pd-catalyzed hydrogenation and polycondensation with an aromatic dial-dehyde. High crystallinity and permanent porosity of the layered two-dimensional (2D) structure were established...

Crystal Engineering Hydrogen bonding in supramolecular assemblies of weak π‐electron donors and acceptors can cause a strong charge transfer. Modifying the acceptor leads to different types of semiconductivity, as described by D. F. Perepichka et al. in their Research Article on page 17312 ff.

Two novel star-shaped triarylamine-based hole transport materials with triphenylamine (STR1), or a partially oxygen-bridged triphenylamine (STR0), as core and para-substituted triphenylamine side arms were synthesized, fully characterized and studied in perovskite solar cells. Their thermal, optical, electrochemical and charge transport properties...

We report a series of highly emissive azatriangulenetrione (TANGO) solids in which the luminescent properties are controlled by engineering the molecular packing by adjusting the steric size of substituents. The co‐alignment of “phosphorogenic” carbonyl groups within the π‐stacks results in an almost pure triplet emission in HTANGO, TCTANGO, TBTANG...

We report a series of highly emissive azatriangulenetrione (TANGO) solids in which the luminescent properties are controlled by engineering the molecular packing by adjusting the steric size of substituents. The co‐alignment of ‘phosphorogenic’ carbonyl groups within the π‐stacks results in an almost pure triplet emission in HTANGO, TCTANGO, TBTANG...

Kristall‐Engineering Wasserstoffbrücken in supramolekularen Anordnungen schwacher π‐Elektronendonoren und ‐akzeptoren können einen starken Ladungstransfer verursachen. Eine Modifizierung des Akzeptors führt zu verschiedenen Arten halbleitenden Verhaltens, wie D. F. Perepichka et al. in ihrem Forschungsartikel auf S. 17473 berichten.

We report on the synthesis of a covalent organic framework based on the low-symmetry 1,3-benzenediboronic acid precursor. Two distinct polymorphs are obtained, a honeycomb network and Sierpiński triangles, as elucidated...

π‐Conjugated organic materials possess a wide range of tunable optoelectronic properties which give rise to many device applications. These properties are dictated by their molecular structure and their supramolecular arrangement. While much efforts in the past decades have been put into tuning the molecular structure to achieve desired properties,...

Conjugated organic materials possess a wide range of tunable optoelectronic properties which are dictated by their molecular structure and supramolecular arrangement. While many efforts have been put into tuning the molecular structure to achieve the desired properties, rational supramolecular control remains a challenge. Here, we report a novel se...

Hybrid heterostructures formed by ordered molecular layers on bidimensional materials can lead to unique properties differing from those of their bulk phases. By employing principles of dynamic covalent chemistry, we have synthesized a series of conjugated polyimines that form epitaxially ordered monolayers on graphene. The interplay of the molecul...

The formation of ordered molecular structures on surfaces is determined by the balance between molecule-molecule and molecule-substrate interactions. Whether the aggregation process is guided by non-covalent forces or on-surface reactions, a deeper understanding of these interactions is pivotal to formulating a priori predictions of the final struc...

We report the first π-conjugated macrocyclic system with an oligofuran backbone. The calculated HOMO–LUMO gap is similar to that of the corresponding linear polymer, indicating a remarkable electron delocalization. The X-ray structure reveals a planar conformation, in contrast to the twisted conformation of macrocyclic oligothiophenes. The intermol...

The facile synthesis of a series of benzodithiophene (BDT)- and indacenodithiophene (IDT)-based A-D-A oligomers with different end groups is reported and their properties studied by optical spectroscopy, electrochemistry and DFT calculations. The permutation of central and terminal units tunes the optoelectronic properties and photovoltaic device c...

Designing structural order in electronically active organic solids remains a great challenge in the field of materials chemistry. Now, 2D poly(arylene vinylene)s prepared as highly crystalline covalent organic frameworks (COFs) by base‐catalyzed aldol condensation of trimethyltriazine with aromatic dialdehydes are reported. The synthesized polymers...

Kristalline zweidimensionale kovalente organische Gerüste (COFs) aus Polyarylenvinylenen wurden durch basenkatalysierte Aldolkondensation von Trimethyltriazin mit einer Serie von aromatischen Dialdehyden synthetisiert. Die erhaltenen COFs sind hydrolysestabil und hoch fluoreszierend (Quantenausbeute ≤50 %). Versetzen mit protischen Lösungsmitteln f...

We report on mixed ordered monolayers of the electron acceptor-type molecule tetracyano-2,6-naphthoquinodimethane (TNAP) and the electron donor-type molecule hexathiapentacene (HTPEN). This investigation was motivated by the general question which type of mixed stoichiometric structures are formed on a surface by molecules that are otherwise typica...

The gate dielectric layer is one of the important components in organic thin film transistors (OTFTs) which affects the charge mobility, power consumption and stability of the device. Here, we report new composite polymer dielectrics prepared by sol-gel chemistry from commercial siloxanes and poly(vinyl alcohol), featuring a high dielectric constan...

Ullmann coupling of halogenated aromatics is widely used in on-surface synthesis of two-dimensional (2D) polymers and graphene nanoribbons. It stands out among other reactions for regioselective connecting aromatic monomers into 1D and 2D π-conjugated polymers, whose final structure and properties are determined by the initial building blocks. Than...

Ullmann coupling or, more generally, dehalogenative aryl-aryl coupling, is one of the most widely exploited chemical reactions to obtain one- and two-dimensional polymers on metal surfaces. It is generally described as a two-step reaction: (i) dehalogenation, resulting in the formation of a stable intermediate phase and subsequent (ii) C-C coupling...

Controlled double-deck packing is an appealing means to expand upon conventional 2D self-assembly which is critical in crystal engineering, yet it is rare and poorly understood. Herein, we report the first systematic study of double-deck assembly in a series of alkylated aminoquinone derivatives at the liquid-solid interface. The competition betwee...

Understanding how molecules interact to form large scale hierarchical structures on surfaces holds promise for building designer nanoscale constructs with defined chemical and physical properties. Here, we describe early advances in this field and highlight upcoming opportunities and challenges. Both direct intermolecular interactions and those tha...

Guest editors Qichun Zhang, Dmitrii Perepichka and Zhenan Bao introduce this Journal of Materials Chemistry C themed issue on organic semiconductors, in celebration of Professor Fred Wudl's fifty-year contribution to the field.

Tetrathiafulvalene (TTF) is one of the most widely used building blocks for organic conductors and redox-active materials. The ability to control the supramolecular structure of these materials, particularly at interfaces, is critical for application in device. In this work, we show how the structure of N-alkylated tetrathiafulvalenecarboxyamide TT...

.Ullmann coupling is the most common approach to form surface-confined one- and two-dimensional conjugated structures from haloaryl derivatives. The dimension of the formed nanostructures can be controlled by the number and location of halogens within the molecular precursors. Our study illustrates that the type of halogen plays an essential role i...

This study reports a new simple organic semiconductor 2,6-bis(4-methoxyphenyl)naphthalene (BOPNA) with unprecedentedly large band gap of 3.35 eV and an apparent hole mobility of ≈1 cm2 V–1 s–1 measured in thin-film organic field-effect transistors in a saturation regime. This large band gap leads to complete optical transparency in the visible rang...

Diketopyrrolopyrrole (DPP) is a widely used building block for high mobility ambipolar semiconductors. Hydrogen bonding of N-unsubstituted DPPs has recently been identified as a tool to control their solid state structure and properties of semiconducting films, yet little is known about supramolecular packing of H-bonded DPP derivatives. Here we re...

An unexpected morphology comprising patchy nanofibers can be accessed from the self-assembly of an all-conjugated, polyselenophene-block-polythiophene copolymer. This morphology consists of very small (<10 nm), polythiophene- and polyselenophene-rich domains and is unprecedented for both conjugated polymers and diblock copolymers in general. We pro...

An unexpected morphology comprising patchy nanofibers can be accessed from the self-assembly of an all-conjugated, polyselenophene-block-polythiophene copolymer. This morphology consists of very small (<10 nm), polythiophene- and polyselenophene-rich domains and is unprecedented for both conjugated polymers and diblock copolymers in general. We pro...

A smart polymer is developed by in situ fabrication of polyacrylamide hydrogel with polyiodide. The resulting PAM hydrogel doped with polyiodide showed a high sensitivity to temperature and humidity. Its special humidity-response behavior with high responsivity makes the described hydrogel a highly promising material for building temperature- and h...

Surface-confined polymerization via Ullmann coupling is a promising route to create one- and two-dimensional covalent π-conjugated structures, including the bottom-up growth of graphene nanoribbons. Understanding the mechanism of the Ullmann reaction is needed to provide a platform for rationally controlling the formation of these materials. We use...

The adsorption of C60-malonic derivatives C61(CO2H)2 and C66(CO2H)12 on Au(111) and a pentafluorobenzenethiol-modified Au substrate ([email protected]/* */) has been investigated using scanning tunneling microscopy (STM) at a liquid-solid interface. Monofunctionalized C61(CO2H)2 forms a hexagonal close-packed overlayer on Au(111) and individual ali...

Understanding the structural organization and growth of organic molecules on self-assembled monolayers (SAMs) is crucial for achieving high performance SAM-based electronic devices. We report herein C60 adsorption onto ben-zenethiol (BT), pentafluorobenzenethiol (PFBT), and octanethiol (C8SH) SAM modified Au(111) studied using STM at the liquid-sol...

A comprehensive investigation of the complementary H-bonding-mediated self-assembly between dipyrrolo[2,3-b:3′,2′-e]pyridine (P2P) electron donors and naphthalenediimide/perylenediimide (NDI/PDI) acceptors is reported. The synthesis of parent P2P and several aryl-substituted derivatives is described, along with their optical, redox, and single-crys...

An electroactive polymer poly[4,7-bis(3,6-dihexyloxy-thieno[3,2-b]thiophen-2-yl)]-benzo[c][1,2,5]thiadiazole is synthesized and applied as a color-changing electrode material in supercapacitors via spray coating method. Using poly(3,4-ethylenedioxythiophene) as the negative electrode, the all-polymer asymmetric supercapacitors provide an energy den...

Here we report the synthesis of cyclic samples of poly(3-hexylthiophene) (P3HT, degrees of polymerization = 25, 40, and 75) and poly(3-heptylselenophene) (P37S, DP = 30). Cyclization was accomplished using a mild alkyne–alkyne homocoupling procedure. Alkyne-terminated poly(ethylene glycol) was then coupled to residual uncyclized polymers, which wer...

A molecular necklace of polypseudorotaxanes was prepared by threading β-cyclodextrins (β-CD) onto biodegradable and thermoresponsive polyurethanes derived from bile acids. These polyurethanes were synthesized via a simple step condensation of bile acid-based dicarbonate with poly(ethylene glycol)-diamine. The β-CD rings slide onto the poly(ethylene...

A molecular necklace of polypseudorotaxanes was prepared by threading β-cyclodextrins (β-CD) onto biodegradable and thermoresponsive polyurethanes derived from bile acids. These polyurethanes were synthesized via a simple step condensation of bile acid-based dicarbonate with poly(ethylene glycol)-diamine. The β-CD rings slide onto the poly(ethylene...

Nitrogen containing polycyclic aromatics are attractive π-functional materials due to their stability and interesting electronic and optical properties. As such, new avenues for the incorporation of nitrogen heteroatoms into arenes are desirable. The visible-light photocyclization of vinyl azides is an efficient method to form nitrogen heterocycles...

Highly unusual properties of acene-based quinones 1A and 1T are reported. They undergo an unexpected combination of Michael and carbonyl additions of aryllithium leading to new triarylated benzoperylenes 3A and 3T. Uncharacteristically for quinones, 1A and 1T display vibronically split absorption bands and small Stokes shifts. The absorption/emissi...

Lanthanide doped upconverting nanoparticles (UCNPs) have emerged as a new class of luminescent materials, with major discoveries and overall significant progress during the last decade. Unlike multiphoton absorption in organic dyes or semiconductor quantum dots, lanthanide doped UCNPs involve real intermediate quantum states and convert infrared (I...