Boron Subphthalocyanine Research Articles

Exploring the Spatial Arrangement of Cs-Symmetric Boron Subphthalocyanine Hybrid Crystals by Tuning Arene–Perfluoroarene Interactions

Exploring the Spatial Arrangement of <i>C</i>_s-Symmetric Boron Subphthalocyanine Hybrid Crystals by Tuning Arene–Perfluoroarene Interactions

Monomeric and Dimeric Boron (III) Subphthalocyanines Functionalized with 4-Hydroxy-Benzoic Acid as Potential Photosensitizers and Photocatalysts in Sulfoxidation.

Axial modification of boron (III) subphthalocyanine bromides with 4-hydroxy-benzoic acid successfully led to the formation of the macrocycles with anchored 4-carboxyphenoxy group [RsPcPHBA] (R=tBu, H) in the axial position and to a new dimer [sPcPHBAsPc] as minor product. Tri-tert-butyl and unsubstituted subphthalocyanines bearing benzoate ([tBusPcBA], [sPcBA]), phenoxy-group ([tBusPcOPh], [sPcOPh])) in the axial position, have been also investigated as well as control sPcs. All compounds were characterized by NMR, IR, UV-Vis and mass spectrometry. The electrochemical properties were studied using cyclic voltammetry (CV) and square wave voltammetry (SWV). Singlet oxygen generation was systematically measured for all synthesized [RsPcX] by kinetic method of chemical trap decomposition (DPBF) and by determination of phosphorescence of singlet oxygen (at 1270 nm). Axially modified subphthalocyanines exhibit high quantum yields of singlet oxygen (1O2) generation (0.47-0.62). The observed exceptional photostability in oxygen-saturated ethanol or toluene solutions and high 1O2 quantum yields allows to use [tBusPcPHBA] as photocatalysts of selective oxidative transformations of organic sulfides to sulfoxides. Loading the catalyst to 9.7 ⋅ 10-2 mol % made it possible to achieve complete conversion of the substrate (TON up to 1700).

Enhancing Specific Detectivity and Device Stability in Vacuum-Deposited Organic Photodetectors Utilizing Nonfullerene Acceptors.

Organic photodetector (OPD) studies have undergone a revolutionary transformation by introducing nonfullerene acceptors (NFAs), which provide substantial benefits such as tunable band gaps and enhanced absorption in the visible spectrum. Vacuum-processed small-molecule-based OPD devices are presented in this study by utilizing a blend of boron subphthalocyanine (SubPc) and chlorinated subphthalocyanine (Cl6SubPc) as the active layer. Four different active layer thicknesses are further investigated to understand the intrinsic phenomena, unveiling the suppression of dark current density while maintaining photoexcitation and charge separation efficiency. Experimental results reveal that, at an applied bias of -3 V, the 50-nm-thick active layer achieves a remarkably low dark current density of 1.002 nA cm-2 alongside a high external quantum efficiency (EQE) of 52.932% and a responsivity of 0.226 A W-1. These impressive performance metrics lead to a specific detectivity of 1.263 × 1013 Jones. Furthermore, the findings offer new insights into intrinsic phenomena within the bulk heterojunction (BHJ), such as thermally generated current and exciton quenching. This integration is potentially well-heeled to revolutionize display technology by combining high-sensitivity photodetection, offering new possibilities for novel display panels with sensing applications.

The influence of the axial group on the crystal structures of boron subphthalocyanines.

The crystal structures of 16 boron subphthalocyanines (BsubPcs) with structurally diverse axial groups were analyzed and compared to elucidate the impact of the axial group on the intermolecular π-π interactions, axial-group interactions, axial bond length and BsubPc bowl depth. π-π interactions between the isoindole units of adjacent BsubPc molecules most often involve concave-concave packing, whereas axial-group interactions with adjacent BsubPc molecules tend to favour the convex side of the BsubPc bowl. Furthermore, axial groups that contain O and/or F atoms tend to have significant hydrogen-bonding interactions, while axial groups containing arene site(s) can participate in π-π interactions with the BsubPc bowl, both of which can strongly influence the crystal packing. Bulky axial groups did tend to disrupt the π-π interactions and/or axial-group interactions, preventing some of the close packing that is seen in BsubPcs with less bulky axial groups. The atomic radius of the heteroatom bonded to boron directly influences the axial bond length, whereas the axial group has minimal impact on the BsubPc bowl depth. Finally, the crystal growth method did not generally appear to have a significant impact on the solid-state arrangement, with the exception of water occasionally being incorporated into crystal structures when hygroscopic solvents were used. These insights can help with the design and fine-tuning of the solid-state structures of BsubPcs as they continue to be developed as functional materials in organic electronics.

Progress on the Development of Boron Subphthalocyanines (BsubPcs) and Subnaphthalocyanines (BsubNcs) Including Hybrids and Their Sustainability

Our group focuses on molecular design, synthetic methods and in-depth characterization of boron subphthalocyanines (BsubPcs) and subnaphthalocyanines (BsubNcs)[1] to apply them to organic electronics.[2] BsubPcs, BsubNcs and their hybrids called Bsub(Pc3-p-Ncp) are macrocycles with central boron atom and are p-conjugated macrocycles. Our focal point balances between the basic and applied chemistry, chemical engineering and their in-depth physical properties (electrochemistry included). Once materials are developed, we merge them into organic electronics for application into organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs)/organic solar cells (OSCs).For this presentation, all points above will be factored in and I will focus on our progress on the development of hybrids, and mixed alloys and none mixed alloys of BsubNcs,.Regarding hybrids, they are a mixture of BsubPcs and BsubNcs, we named as X-RnBsub(Pc3-p-Ncp) – ‘p’ being the numbers of the substitutions; they were formed via reaction of BCl3 and a statistical distribution of phthalonitrile and 2,3-dicyanonaphthalene; X the axial substituent, Rn the number of peripheral substitutions, Pcp the number of 6 p-conjugated bonds, Ncp the number of 10 p-conjugated bonds (Figure).[3] We found that X-RnBsub(Pc1-Nc2) have low photostability, therefore, we developed a ‘statistical’ synthetic methodology to target X-RnBsub(Pc2-Nc1)s, and therefore could be purified to enable physical characterization. Their absorption spectra are as wide if BsubPc+BsubNc was mixed together, therefore, has potential to harvest a larger scope of photons for OPVs or to achieved FRET transfer from a host to emit via OLED. We also confirmed their electrochemical oxidation and reduction stability and their photoluminescence.More recently, we developed a new methodology called ‘steric hinderance’ to have even a higher yield of the X-RnBsub(Pc3-p-Ncp) hybrids, and the achievement was also based on computational modelling. I will also outline this approach.In the past as we have shown that BsubNcs end up being a mixed alloyed composition with random bay-position halogenation that is formed during the reaction of BCl3 with 2,3-dicyanonaphthalene at temperature.[4] The random bay-position halogenation has been shown to be impactful in a positive way within OPV devices, negative within OLED devices and also has electrochemical variations. Ongoing, given it is random halogenation, and some of the positive outcomes, this justifies considering additional mixed alloyed compositions.We have recently been able to develop a separation method for the mixed alloyed BsubNc compositions and acquired data to show the impact of the percentage/number of bay-position halogens, chlorine and bromine included, on the electrochemical potentials and the photoluminescence.[5] We have also applied a computational model to look at the relative impact of the random bay-position halogenation on the electronics.[6] We have found that the frequency of halogenation has a larger impact on the predicted HOMO/LUMO energy levels than does the random halogen positioning around the bay-positions of the BsubNcs. As this computational data is therefore comparable to the acquired electrochemical data.I will also present a new synthetic methodology to avoid the random bay-position halogenation of the associated BsubNcs. We also have recently within these semesters developed alternative chemistry to more tune the mixed alloys of the BsubNcs. This will also be a part of the presentation.We have also recently developed an AI-ML method to further accelerate the BsubNc development. The focal point of this approach was to have bay-position substitutions to then not have any random bay-position halogenation of the BsubNcs. So, these current and upcoming outcomes will also be a part of the presentations.For this presentation, I will also be outlining the sustainability of these great macrocyclic compounds. Claessens, C. G.; et al, Subphthalocyanines, Subporphyrazines, and Subporphyrins: Singular Nonplanar Aromatic Systems. Chem. Rev. 2014, 114 (4), 2192-2277.Morse, G. E.; et al, Boron Subphthalocyanines as Organic Electronic Materials. ACS Appl. Mater. & Interfaces 2012, 4 (10), 5055-5068.Farac, N.F.; et al, Cs-Symmetric, Peripherally Fluorinated Boron Subphthalocyanine–Subnaphthalocyanine Hybrids: Shedding New Light on Their Fundamental Photophysical Properties and Their Functionality as Optoelectronic Materials. J. Phys. Chem. C 2023, 127 (1), 702–727.Dang, J. D.; et al, The mixed alloyed chemical composition of chloro-(chloro)n-boron subnaphthalocyanines dictates their physical properties and performance in organic photovoltaic devices. J Mater. Chem. A 2016, 4 (24), 9566-9577.Holst, D.P.; et al, Enhanced analytical and physical characterization of mixtures of random bay-position chlorinated boron subnaphthalocyanines enabled by an established partial separation method (a part 2). New J. Chem. 2021, 45, 21082-21091.Holst, D.P.; et al, Updated Calibrated Model for the Prediction of Molecular Frontier Orbital Energies and Its Application to Boron Subphthalocyanines. J. Chem. Inf. Model. 2022, 62 (4), 829–840. Figure 1

Structure and Properties of Novel Macrocylic Structures: A First Principles Perspective

Understanding of the structure and properties of novel macrocyclic structures can be enhanced strongly through the juxtaposition of experimental data and first principles computational data. In this lecture, I will review recent examples of such insights. Specifically, I will discuss structure, bonding, and electronic properties in fused iron corroles, in boron subphthalocyanine halides and pseudohalides, and in a novel polymorph of Cu Phthalocyanine.

Preparation and Optical and Electrochemical Properties of Boron (III) Octafluorosubphthalocyanines with One Triselenole and One Diselenet Ring.

Unsymmetric boron (III) subphthalocyanines with a triselenole ring or a diselenete ring and eight fluoro groups were prepared by the reaction of 5,6-dicyano-4,7-diethylbenzo-[1,2,3]triselenole and tetrafluorophthalonitrile with trichloroborane in xylene. The reaction was accompanied by a contraction of the triselenole ring to the diselenete ring. The substrate, dicyanobenzo[1,2,3]triselenole, was prepared by a new procedure via a photolytic demethylenation reaction of 3,7-diethyl[1,3]diselenolophthalonitrile using a 10 W white LED light. While triselenolosubphthalocyanine was treated by triphenylphosphine to give the diselenete derivative, the reaction of diselenetosubphthalocyanine with Woolion's reagent produced the expanded triselenole ring. The diselenete derivative reacted with tetrakis(triphenylphosphine)platinum to yield the corresponding platinum complex with Se-Pt bonds. Q-band absorption for the products appeared at around λmax=590 nm in the UV-vis spectrum and weak emission was observed at about λe=620 nm. When diselenetosubphthalocyanine was treated with pentachloro antimonate in dichloromethane or sodium metal in hexane/tetrahydrofuran, the solution showed strong ESR signals. The structures of model compounds were optimized using the DFT method with the Gaussian 09 program at the B3LYP/6-31G (d, p) level.

Redox Active Ligands for Catalyzing the Hydrogen Evolution Reaction.

Boron subphthalocyanines with chloride and fluoride axial ligands and three antimony complexes chelated by corroles that differ in size and electron-richness were examined as electrocatalysts for reduction of protons to hydrogen. Experiment- and computation-based investigations revealed that all redox events are ligand-centered and that the meso-C of the corroles and the peripheral N atoms of the subphthalocyanines are the largely preferred proton-binding sites.

Optimizing the preparation of bromo phthalonitriles and piloting them to peripherally brominated boron subphthalocyanines

Boron subphthalocyanines (BsubPcs) are versatile molecules with advantageous properties for applications. The BsubPcs are synthesized by the cyclotrimerization of a phthalonitrile and are composed of three isoindole subunits bound by three aza-/imine-bridging nitrogens. There are a variety of BsubPc derivatives shown within the literature due to the differentiation of a phthalonitrile precursor. The differentiation of a phthalonitrile enables the peripheral functional groups. The BsubPcs can be derivatized in two steps: First step is the cyclotrimerization of a phthalonitrile in the presence of a strong Lewis Acid, typically a boron trihalide (BX3) and enables a remaining axial substituent that is a B-X[Formula: see text] bond; second step is optional, the B-X[Formula: see text] bond can react with a nucleophile and results in B-X[Formula: see text]. If the starting phthalonitrile is asymmetric, it will result in a combination of isomers. For this study, our approach is to have bromine substituents and to study their physical properties to see if applicable to organic electronic applications; chlorine and fluorine have been in past studies as halogens are unique and variations may present useful tools as they are known for electronegativities. The general phthalonitrile with no substitutions is produced in industry from [Formula: see text]-xylene. There are a variety of ways to synthesize other phthalonitriles with halogens. However, phthalonitriles can also be made by a method that has the most versatility with its substituents and can start with phthalic acid and go to phthalic anhydride to phthalimide to phthalamide and final to phthalonitrile; it is also possible to synthesize a phthalimide directly from phthalic acid, and this is part of this study as we were focusing on bromination, we also wanted to optimize the synthetic pathways to brominated phthalonitriles, and we took an engineering perspective and for this study, we wish to show you.

DFT and TD DFT study of oxodiboron(III) phthalocyanine and peculiarities of spectral behavior and acid–base properties of its tert-butyl substituted derivative in solutions

Molecular and electronic structures of transoid and cisoid forms of oxodi(fluoroboron(III)) complex of phthalocyanine [O(FB)2Pc] in the ground and excited states were studied using DFT and TD DFT methods. The peculiarities of the electrochemical and spectral properties of the tetra-tert-butyl substituted complex existing in the transoid form in organic solvents and in acid medium were considered in comparison with 1:1 complexes formed by aluminum subgroup metals and boron(III) subphthalocyanine. Coordination of two boron atoms in the coordination cavity of the phthalocyanine macrocycle leads to its tetragonal distortion both in the cisoid and especially in the transoid forms and stabilizes the frontier π-molecular orbitals, especially the lowest unoccupied MO. This results in the bathochromic shift of the long-wave Q band and strongly facilitates the reduction of macrocycle occurring for the transoid form at −0.19 V versus Ag/AgCl in dimethylformamide (DMF). Spectrophotometric titration in CH2Cl2-CF3COOH medium showed that the basicity of the meso-nitrogens is decreased upon coordination of two boron atoms. Slow deborylation can occur either in a strongly acid medium (96% H2SO4) or in the presence of water in DMF. The absence of fluorescence and ability to generate singlet oxygen is explained by quenching of the excited state due to conformation flexibility of the macrocycle and inversion of the coordination center in the transoid form.

Redox behaviour of boron subphthalocyanine carbon nanotube composites

Organic redox-active carbon composites can be used as sustainable electrode materials in electrochemical energy storage systems. Among numerous redox active species, peripherally dodecafluorinated boron subphthalocyanines (F12BsubPcs) have shown electrochemical redox activities in the solution phase. Nonetheless, the electrochemical properties of solid F12BsubPcs when compositing with nano carbon warrants further investigation for potential applications in energy storage. In this work, nanometer scale axially brominated F12BsubPcs (Br-F12BsubPcs) were coated onto bare graphitized multiwalled carbon nanotubes (GCNT) and COOH-functionalized GCNT (COOH-GCNT) by a facile dip coating method to produce two composites and to compare the effects of the surface functional group interactions with Br-F12BsubPcs. While the surface chemical and morphological characterizations confirmed the presence of Br-F12BsubPc coating on both bare and COOH-GCNTs, the coverage on the latter was higher. Cyclic voltammetric studies in acidic electrolyte revealed a highly reversible redox couple on both composites with Br-F12BsubPc coated COOH-GCNT demonstrating up to c.a. 70% higher redox peak currents than with Br-F12BsubPc coated GCNT. Further analyses of the coated COOH-GCNT suggested a 2-electron transfer process. The charge transfer has fast-kinetics and a strong dependence on the proton concentration. The composites produced in this work demonstrate potential for future application in energy storage and can provide a strategy for developing BsubPc-based carbon composites.

Efficient photocatalytic degradation of antibiotics by binary heterojunction complex boron subphthalocyanine bromide/bismuth oxychloride

The development of stable and efficient heterojunction photocatalysts for wastewater environmental purification exhibits a significant challenge. Herien, a promising binary heterojunction complex comprising boron subphthalocyanine bromide/bismuth oxychloride (SubPc-Br/BiOCl) was successfully synthesized using the hydrothermal method, which involved the self-assembled of SubPc-Br on the surface of BiOCl via intermolecular π-π stacking interactions to compose an electron-transporting layer. The photocatalytic efficiency of SubPc-Br/BiOCl for the degradation of tetracycline and the minocycline exhibited a substantial improvement of 29.14% and 53.72%, respectively, compared to the original BiOCl. Experimental characterization and theoretical calculations elucidated that the enhanced photocatalytic performance of the SubPc-Br/BiOCl composite photocatalysts stemmed from the S-scheme electron transport mechanism at the interface between BiOCl and SubPc-Br supramolecules, which broadened the visible light absorption range, increased the carrier molecular efficiency, and accelerated the carriers. Furthermore, molecular dynamic (MD) simulations provided insights into the action trajectories of the two semiconductors, revealing that the presence of SubPc-Br enhances the water and organic pollutant adsorption capabilities of the BiOCl surface within the supramolecular array system. In conclusion, the synthesis and analysis of the binary heterojunction complex SubPc-Br/BiOCl yield valuable insights into the efficient photocatalytic degradation of antibiotics, holding great promise for diverse environmental applications.

Spectroscopic, physicochemical characterizations and photonics applications on boron subphthalocyanine chloride as organic electronics

This work shows the structural, thermogravimetric, optical, and electrochemical properties of boron subphthalocyanine chloride (B-subPc-Cl) as organic electronic material. The Fullprof Suite program and Rietveld analysis were used to refine and index the crystal structure of B-subPc-Cl. The thermogravimetric analysis (TGA) and the differential thermogravimetric analysis (dTG) were used to study the kinetic thermogravimetric factors using the Horowitz-Metzger's and Coats-Redfern methods. The absorption spectra of B-subPc-Cl contain two strong absorption bands (Soret-like band and Q-like band). The oscillator strength and electrical dipole strength were estimated by using a Gaussian fitting of the molar absorptivity (εmolar) of the B-subPc-Cl. The HOMO-LUMO and the band gap of B-subPc-Cl were calculated by using cyclic voltammetry measurement. Details of the UV-Vis –NIR absorption spectra and optical band gap for B-subPc-Cl are also provided. Density-functional theory (DFT) method has been utilized to obtain geometrically optimized structure for the studied compound. The theoretical calculations agreed with the experimental results. The obtained results point out the prospects of B-subPc-Cl for the organic electronic applications.&#x0D; KEY WORDS: Subphthalocyanine, Optical properties, TGA, Cyclic voltammetry, DFT method&#x0D; Bull. Chem. Soc. Ethiop. 2024, 38(2), 527-538. &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v38i2.19&#x0D;

Boron subphthalocyanine axial groups: a comprehensive set for studying the tuning of photophysical and electrochemical properties

The notable impact of a wide array of axial groups on the quantum yield and electrochemical redox properties provides a guide for future design of BsubPcs and other macrocycles for organic electronic and other applications.

Structure–Property Relationships with Functionalized Subphthalocyanines: Toward Photovoltaic Devices More Stable to Photooxidative Degradation Mediated by Singlet Oxygen

AbstractIn this work, the overarching goal of improving the photooxidative stability of organic components used in photovoltaic devices is addressed, focusing on the common problem of degradation mediated by singlet molecular oxygen. Through a systematic exploration of boron subphthalocyanines (SubPcs), the influence of donor and acceptor substituents on the SubPc's redox properties has been examined, including the SubPc's ability to (1) act as a photosensitizer for singlet oxygen generation and (2) deactivate singlet oxygen are examined. How singlet oxygen formation and removal are influenced by linking together three SubPcs in a compact structure and by linking a SubPc to another molecular unit of relevance for organic photovoltaics (indenofluorene‐extended tetrathiafulvalene) is also examined. Synthetic protocols rooted in acetylenic scaffolding, experimental and computational structure–property relationships (optical and redox properties, singlet oxygen quantum yields, and removal kinetics), and characteristics of a functional photovoltaic device using a SubPc molecule are presented, demonstrating that cyano functionalization results in remarkably enhanced organic photovoltaic device stability.

Supramolecularly engineered S-scheme SubPc-Br/MoS2 photocatalyst nanosheets for enhanced photocatalytic degradation of antibiotics

Developing a simple, low-cost, high-yield, and controllable strategy for preparing various functionalized MoS2-based composite materials remains a challenge. This study innovatively utilizes boron subphthalocyanine bromide (SubPc-Br) as a photosensitizer, which self-assembles on MoS2 via intermolecular π-π stacking, creating a SubPc-Br/MoS2 organic–inorganic semiconductor system. This addresses a research gap, employing subphthalocyanines as MoS2 sensitizers. The SubPc-Br/MoS2 heterojunction exhibited excellent photocatalytic activity for the degradation of antibiotics in water under solar irradiation. The rate constants for the photocatalytic degradation of CTC and CIP by SubPc-Br/MoS2 were 4.66 and 5.93 times higher than those of pristine MoS2, respectively. The significant improvement in photocatalytic performance is attributed to the efficient charge separation and transfer induced by the unique S-Scheme charge transfer mechanism, which has been verified by different theoretical and experimental results. We demonstrate that the photochemical activity of O2 molecules adsorbed on MoS2(100) is site-sensitive, with O2 preferentially adsorbing on the Mid-site location with higher electron transport capability. This study provides a new perspective for enhancing photocatalytic performance by constructing an artificial photosynthetic system with an S-scheme heterojunction.

Multi-Redox Systems Based on Boron Subphthalocyanines

Boron subphthalocyanines (SubPcs) are cone-shaped molecules comprised of three isoindole units bridged by aza-linkages and with a central boron atom containing an axial substituent. SubPcs are strong chromophores, but also redox-active molecules undergoing both reversible oxidation and reduction. By linking together SubPc units, multi-redox systems emerge that can take several redox states. Here I will show a variety of such scaffolds where SubPc units are either linked together at axial or peripheral positions by various acetylenic bridges. Bridges include various acyclic oligo(en)ynes and cyclic radiaannulenes containing both endo- and exocyclic carbon-carbon double bonds.1 The length and nature of the bridging unit determines whether the SubPc units are independent redox centers or whether there is communication between the units. Moreover, I will present structures were isoindole units of SubPc are replaced by thienopyrrole units2 as well as structures where the SubPc is linked to another redox-active unit, such as a triangulene.3 Experimentally determined redox potentials were compared to theoretically calculated ones, allowing us to move forward a reliable theoretical method for predicting redox properties. References a) H. Gotfredsen, L. Broløs, T. Holmstrøm, J. Sørensen, A. V. Mu ñ oz, M. D. Kilde, A. B. Skov, M. Santella, O. Hammerich, M. B. Nielsen, Org. Biomol. Chem. 2017, 15, 9809-9823; b) L. Broløs, M. D. Kilde, M. B. Nielsen, Org. Biomol. Chem. 2020, 18, 6077-6085; c) A. U. Petersen, M. G. Rasmussen, M. C. H. Thomsen, A. Ceuninck, M. B. Nielsen, Arkivoc 2020, vii, 145-157; d) H. Lissau, C. L. Andersen, F. E. Storm, M. Santella, O. Hammerich, T. Hansen, K. V. Mikkelsen, M. B. Nielsen, Chem. Commun. 2018, 54, 2763-2766. H. Gotfredsen, F. E. Storm, A. V. Muñoz, M. Santella, A. Kadziola, O. Hammerich, K. V. Mikkelsen, M. B. Nielsen, Chem. Eur. J. 2017, 23, 16194-16198. M. G. Rasmussen, M. F. Jespersen, O. Blacque, K. V. Mikkelsen, M. Juríček, M. B. Nielsen, Energy Sci. Eng. 2022, 10, 1752-1762. Figure 1

Progress on Hybrids and Mixed Alloys of Boron Subphthalocyanines (BsubPc) and Boron Subnaphthalocyanines (BsubNc); Tuning the Electrochemical Properties Towards Organic Electronic Applications

Our research and development focus has been on the molecular design, synthetic methodology and in-depth characterization of boron subphthalocyanines (BsubPcs) and subnaphthalocyanines (BsubNcs) to apply them to organic electronic applications. BsubPcs, BsubNcs and their hybrids are macrocycles with a chelated central boron atom via nitrogen bonding, and is a p-conjugated macrocyclic material. Our focal point balances between the basic and applied chemistry, chemical engineering, their in-depth physical properties (electrochemistry included). We also do computational modelling. Once materials are developed, we merge them into organic electronics to function as light emitting, light absorbing and electronic conducting materials within organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs)/organic solar cells (OSCs). The basic electrochemical and photophysical properties, developing and evaluating the properties is critical to move onto such applications.For this presentation, I will focus on our progress on the development of hybrids and mixed alloys of BsubPcs and BsubNcs.Regarding hybrids, they are a mixture of BsubPcs and BsubNcs, and are formed via a reaction of a statistical distribution of phthalonitrile and 2,3-dicyanonaphthalene intermediates on reaction with BCl3; we have named them X-RnBsub(Pcx-Ncy); X the axial substituent, Rn the number of peripheral substitutions, Pcx being the number of 6 p-conjugated bonds, Ncy being the number of 10 p-conjugated bonds (Figure). On first study, we found that X-RnBsub(Pc1-Nc2) have low photostability. Therefore, we moved onto developing a ‘statistical’ synthetic methodology to target highest yields of X-RnBsub(Pc2-Nc1)s, and we did achieve relatively high yields. X-RnBsub(Pc2-Nc1)s therefore could be purified to enable physical characterization. Within a couple past publications, the unique absorption spectra was noted and we have confirmed its uniqueness. The X-RnBsub(Pc2-Nc1)s absorption spectra is as wide as if BsubPc and BsubNc were mixed together. This therefore has good potential to harvest a larger scope of photons from solar or to achieved FRET transfer from a host to emit via an OLED. We then did in-depth first electrochemical characterization, confirmed their electrochemical oxidation and reduction stability and also did in-depth photoluminescence characterization. Therefore, merging X-RnBsub(Pc2-Nc1)s into organic electronic devices as well as other chemistry to synthesis the hybrids is ongoing.Regarding mixed alloys, in the past as we have shown that BsubNcs ended up being a mixed alloyed composition with random bay-position halogenation, that is formed during the reaction of BCl3 with 2,3-dicyanonaphthalene at temperature, which is the process to form the BsubNcs. The random bay-position halogenation has been shown to be impactful in a positive way within OPV devices, negative within OLED devices and also has electrochemical variations and good reversibility. Ongoing, given it is random halogenation, and some of the positive outcomes, this justifies considering additional mixed alloyed compositions.We have also recently shown that mixed alloyed BsubPcs can be formed with three peripheral halogens in the alpha (a) or beta (b) positions, named as Cl-αCl3BsubPc, Cl-βCl3BsubPc, Cl-αF3BsubPc, and Cl-βF3BsubPc. The alloyed mixtures consisted of C1 and C3 isomers of trihalogenated BsubPcs. The physical properties characterization including photophysics, electrochemistry, and thermal characterization, were studied and were also positive and then were engineered into OSCs as electron donors and electrons acceptors to clarify their impact on device performance which had positivity aspects. Therefore, we moved onto developing a set of additional BsubPc mixtures. To be outlined for this presentation, we considered sets of phthalonitrile mixtures to form peripherally halogenated BsubPc mixtures during the formation of BsubPcs from these intermediates. For example, 4,5-dichlorophthalonitrile (Cl2-pn), 4,5-difluorophthalonitrile (F2-pn), tetrachlorophthalonitrile (Cl4-pn), and tetrafluorophthalonitrile (F4-pn) are commercially available compounds that were mixed together and yields a mixture of BsubPc which we named: X-Cl2nF2mBsubPc and X-Cl4nF4mBsubPc (X = Cl or F being a variant, Figure). We then did physical characterization and found positive aspects including electrochemical oxidation and reduction stability. Merging them into organic electronic devices is ongoing and might be present during this presentation time.We did also recently develop additional chemistry methodology to develop additional mixed alloyed BsubPcs. The methodology was to develop phthalonitrile intermediates that have numbers of hydrogen, chlorine and fluorine substitutions and to take them onto the formation of the BsubPc mixed alloys. This is ongoing and may have some aspects to outline during this presentation.We also do computational modelling to look into other relative impacts of the materials being developed, for example the HOMO and LUMO orbital distributions, the local ionization etc. This will also be outlined during this presentation. Figure 1

Reaction Calorimetry and Scale-Up Considerations of Bromo- and Chloro-Boron Subphthalocyanine

The formation mechanism of boron subphthalocyanines (BsubPcs) has thus far evaded researchers, making it nearly impossible to accurately estimate the overall reaction enthalpy─a critical metric for determining chemical process safety for scale-up. To address this gap, reaction calorimetry was used to collect thermokinetic data for a baseline Br-BsubPc reaction at three temperatures and two BBr3 reagent ratios and a proposed semibatch process for Cl-BsubPc. For the Br-BsubPc process, the magnitude of the enthalpy of reaction (ΔHr) increased with increasing reaction temperature, from −244.6 kJ/mol-BBr3 at 25 °C to −332.7 kJ/mol-BBr3 at 50 °C to −391.3 kJ/mol-BBr3 at 75 °C. However, this increase in the magnitude of ΔHr did not result in a noticeable increase in Br-BsubPc yield, achieving 50%, 49%, and 52% yields at 25 °C, 50 °C, and 75 °C, respectively. When the molar equivalence of BBr3 was increased by 1.5× at 25 °C, the magnitude of ΔHr increased slightly (−252.2 kJ/mol-BBr3), but the yield did not improve (47%). Therefore, further attempts were made to try and improve the yield of Br-BsubPc by increasing the molar equivalence of BBr3. It was found that BBr3 equivalencies greater than 0.48 resulted in significant reductions in Br-BsubPc yield. The ΔHr of the semibatch Cl-BsubPc process was −266.5 kJ/mol-BCl3 with a yield of 33%. These processes were assessed based on criticality criteria and were both found to be “Criticality Class 1”, which is relatively safe for scale-up. Based on the calorimetry measurements, preliminary estimates for process conditions and reactor design for scale-up are provided.

Morphology, structural properties, impedance spectroscopy, AC conductivity, and dielectric relaxation properties of boron subphthalocyanine chloride amorphous films

Through the use of thermal evaporation, boron subphthalocyanine chloride (B-subPcCl) films were created. X-ray diffraction pattern reveals that the B-subPcCl is characterized by amorphous nature, while atomic force microscopy images show that the surface topography of B-subPcCl is composed of homogeneous elliptical nanoparticles with grain size and roughness of 90 and 70 nm, respectively. The impedance measurements of B-subPcCl film at the temperature ranges of 298–398 K were studied and were fitted to the analog of a Rp//CPE equivalent electrical circuit model. The relationship between AC conductivity and frequency at different temperatures demonstrated that the correlated barrier hopping (CBH) model dominates the transport charge mechanism between the closest sites. The DC conductivity parameters were calculated, and they were compared with the relative organic compounds. The dependence of the dielectric constant (ε 1) and the dielectric loss (ε 1) on frequency showed a significant decrease of ε 1 and ε 2 values as the frequency increased. At different temperatures, the variation of the imaginary modulus (M 2) of B-subPcCl with frequency showed a relaxation process with an activation energy of 0.066 eV.