Boron subphthalocyanines (BsubPcs) are a class of macrocycles that are often stable and straightforward to synthesize. Their optical properties such as high extinction coefficient and strong fluorescence have led to their incorporation into optoelectronic devices including OLEDs. However, the best demonstrated OLEDs using BsubPc emitters were unable to convert triplet excitons generated through applied bias into light. To address this, we fabricated OLEDs incorporating an assistant dopant into the emissive layer, 2-phenyl-4 '-carbazole-9H-thioxanthen-9-one-10,10-dioxide (TXO-PhCz), capable of thermally converting triplet excitons into singlets, which are then transferred to the BsubPc emitter, a process referred to as hyperfluorescence. We also varied the axial substituent attached to the BsubPc core to determine its effect on the resulting performance. We found that the use of the TADF assistant dopant increased current efficiency up to 200% while maintaining more than 90% emission from the BsubPc in most cases. The best BsubPcs had short alkoxy axial groups, achieving an average current efficiency of 1.34 cd A-1 across a luminance range of up to similar to 103 cd m-2 using tert-butoxy BsubPc. These devices are the most efficient, and pure color OLEDs demonstrated using BsubPcs as the primary emitter at reasonable luminance outputs. These findings highlight the promise of BsubPc emitters in high-performance OLEDs when paired with a TADF assistant dopant, offering a viable route to efficient and color-pure devices.

Herein, we report an investigation into the use of a scientific microwave reactor for the synthesis of chloro-boron subphthalocyanines (Cl-BsubPcs), its derivatives, and the π-extended alternative called chloro-boron subnaphthalocyanine (Cl-Cl n BsubNc). Reaction optimization screening is presented with the aid of a high-pressure liquid chromatography system equipped with a photodiode array detector (HPLC-PDA) and used for quantitative analysis to calculate the conversion of phthalonitriles and 2,3-dicyanonaphthalene to the Cl-BsubPcs and Cl-Cl n BsubNcs, respectively, by leveraging the characteristic UV-vis absorbance profiles of the Cl-BsubPcs and Cl-Cl n BsubNcs. The microwave reaction process was found to reduce the reaction time from multiple hours to 5 to 36 min, reducing the overall time needed for the synthesis of the desired compounds, and provided a streamlined process of optimizing the synthesis of peripherally and axially substituted Cl-BsubPc derivatives. With enhanced heating, difficult-to-synthesize Cl-Cl12BsubPc was found to achieve moderate conversion through multiple microwave irradiation cycles. With this streamlined process, the lack of ethereal cleavage of aryl-aryl ether moieties (i.e., p-tolyl group) attached to the periphery of a Cl-BsubPc was achieved and is also presented. Although random bay halogenation of Cl-BsubNc was not found to be suppressed under the reaction conditions in the microwave, we present the microwave synthesis of Cl-Cl n BsubNcs while tracking random bay halogenation production using HPLC-PDA and confirm their characterization via mass spectrometry.

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 a central boron atom and are p-conjugated macrocycles. Our focal point balances between the basic and applied chemistry, chemical engineering, sustainability and their in-depth physical properties (fluorescence, etc., and electrochemistry always included). Once materials are developed, we merge them into organic electronics: organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs)/organic solar cells (OSCs). Regarding OSCs, we have recently identified the BsubPcs and BsubNcs having good stability outdoors and therefore the OSC application is ongoing and ongoing development. For this presentation, all points above will be factored in. 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).[3a] 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. The absorption spectra of X-RnBsub(Pc2-Nc1)s are as wide if BsubPc+BsubNc was mixed together, therefore, has potential to harvest a larger scope of photons for OPVs/OSCs. We also confirmed their electrochemical oxidation and reduction stability. 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.[3b] We have made progress on engineering the hybrids to the OPVs/OSCs and will outline. 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. We have developed a separation method 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.[5a] Ongoing, given it is random halogenation, and some of the positive outcomes, this justifies considering additional mixed alloyed compositions. We have also applied a computational model[6a] to look at the relative impact of the random bay-position halogenation on the electronics,[6b] and 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.[5b] We also have recently developed alternative chemistry to more tune the mixed alloys of the BsubNcs and have complete ‘bay-position’ halogenation – 6 chlorides.[5c] And OSC device engineering is ongoing. This will also be a part of the presentation. For this presentation, I will also be outlining the sustainability of these great macrocyclic compounds. We have recently identified a more sustainable synthetic/macrocycle formation and to be published. References 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. (a) 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. (b) Farac, N.F.; et al, Bulking Up the Bay-Position Substituents Enables Enhanced Selectivity of Cs-Symmetric Boron Subphthalocyanine– Subnaphthalocyanine Hybrids. Precision Chem, 2024, Vol 2 Issue 4, doi: 10.1021/prechem.4c00012 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. (a) 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. (b) Holst, D.P.; etc al, Triphenyl borates used to avoid the bay-position halogenation of boron subnaphthalocyanines; and for the subnaphthalocyanine, subphthalocyanine and hybrids formation, New J. Chem, 2024, 48, 5127-5143. (c) ...to be published soon. ...to be published soon. Figure 1

We investigate the effect of peripheral fluorination and chlorination on the rate of axial phenoxylation of boron subphthalocyanines (BsubPcs), with Br and Cl as axial ligands, specifically Br-BsubPc, Br-F(12)BsubPc, Br-Cl(12)BsubPc, Cl-BsubPc, and Cl-F(12)BsubPc. For this study, we use various solvents at their reflux temperature to acquire conversion of axial phenoxylation and obtain kinetic data. We found the experimentally observed reactivity of the BsubPcs used in this study followed Br-BsubPc > Cl-BsubPc > Br-F(12)BsubPc approximate to Br-Cl(12)SubPc >> Cl-F(12)BsubPc. This shows that peripheral fluorination or chlorination inhibits the rate of axial phenoxylation and confirms the axial B-Br bonds to be more reactive than B-Cl bonds. Density functional theory (DFT) calculations confirm the observed kinetic data and suggest that phenoxylation proceeds primarily via the Torres mechanism.

Avoiding the random bay-position halogenation of boron subnapthalocyanines and to balance of Lewis's acidity and basicity to enable the formation.

Eighteen boron subphthalocyanines (BsubPcs) axial derivatives were synthesized through axial exchange reactions with Br-BsubPc under relatively mild conditions to systematically study the influence of a structurally diverse array of axial group derivatives on the physical properties of the BsubPcs. The photophysical and electrochemical properties of BsubPcs were investigated through solution-state UV-vis absorbance and fluorescence spectroscopy, relative fluorescence quantum yield (QY), cyclic voltammetry (CV), and differential pulse voltammetry (DPV), as these properties are crucial for the application of BsubPcs in the field of organic electronics. The impact of the axial groups on photophysical properties was evaluated by taking measurements in both toluene and alpha,alpha,alpha-trifluorotoluene as the solvent, and referencing QY to two compounds. The axial group has a minimal impact on the absorbance and fluorescence peak shifts, with alpha,alpha,alpha-trifluorotoluene causing a slight blueshift. The axial group had a significant impact on QY, with values ranging from <1% to >70%, and the majority falling in the 30-60% range, depending on the experimental conditions. Although the trends remained consistent, the solvent and reference compound both had notable impacts on QY. CV revealed some BsubPcs have one reversible reduction and one irreversible or quasi-reversible oxidation, others displayed unique reversibility and/or additional redox processes. The axial groups also influenced the redox potentials, with first oxidation potentials spanning a 194 mV range and first reduction potentials covering a 266 mV range. Electron-withdrawing or electron-donating axial groups impacted the redox behaviour of BsubPcs, suggesting an electronic connection between the axial group and the BsubPc core occurs. This study leads to insights into the axial substituents that should be targeted to be used for other peripherally functionalized BsubPc derivatives for further studies.

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-a bond; second step is optional, the B-X-a bond can react with a nucleophile and results in B-X-b. 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 o-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.

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.

Chloro-boron subphthalocyanine (Cl-BsubPc) is a representative within the phthalocyanine space and is an organic semiconductor that has been applied as an active material in organic photovoltaics (OPVs). Past work has been done to design a synthetic process that is well-suited for reaction scale-up of a BsubPc. This study investigates the life cycle implications of the established Cl-BsubPc synthetic process from an embodied energy standpoint. The embodied energy of the baseline process is modeled as 7929 MJ/kg-Cl-BsubPc using a cumulative energy demand (CED) methodology. The reaction solvent 1,2-dichlorobenzene is identified as the largest contributor to the total embodied energy with a specific CED of 2513 MJ/kg. Alternative aromatic solvents with lower embodied energies were identified from established databases and tested as drop-in replacements for 1,2-dichlorobenzene. A kinetic study was then conducted to investigate the optimal reaction time of several solvents. 2,4-Dichlorotoluene, with a specific CED of 64 MJ/kg, was found to be a viable alternative to 1,2-dichlorobenzene. Cl-BsubPc made from this new process was then incorporated into OPVs, and the device performance was compared to past baseline devices using Cl-BsubPc made from 1,2-dichlorobenzene. The performance was the same, further justifying the adoption of 2,4-dichlorotoluene in the synthesis of Cl-BsubPc and others.

Organic solar cells (OSCs) can be highly affected by environmental stresses like heat, moisture, and sunlight during their service life if they are not encapsulated or if the encapsulation leaks. A deep understanding of how each individual organic layer changes/reacts to various environmental factors is a crucial aspect in designing an effective OSC architecture to ensure the longevity and stability of the materials toward the device's performance. While there are numerous examples of encapsulated OSCs operating outdoors for extended periods of time, there is an insufficiency of information available about the individual stability of the materials involved. The focus of this study is to provide a quantitative assessment of the individual unencapsulated OSC layers when they are exposed to combinations of heat, humidity, and light. Ideally, a similar process can be applied to different organic nanolayers in the future, and the results can be used as a reference. Throughout the accelerated aging process, the most impactful environmental stressor was the presence of strong light. Via UV-vis and fluorescence data acquisition, the chloro-boron subphthalocyanine (Cl-BsubPc) layer was observed to be altered by some combination of hydrolysis and nanostructural change, from the strong incident light, which was not observed if aged in the dark. We also observed significant nanolayer film crystallization for other materials when exposed to humid heat and an increase in film hydrophilicity during the aging process. The nanolayer film crystallization could have also contributed to the loss of pi-conjugation/color, which may not have undergone complete photobleaching. Though there were property changes throughout the accelerated aging process, we feel that the relatively long time scale of most changes highlights a characteristic material stability that would translate strongly to standard operating conditions in encapsulated devices. Adopting these methodologies can also be useful to guide further material development broadly in particularly susceptible materials in the future.

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.

Manipulating the solid-state arrangements of organic electronic materials can profoundly impact the performance of the devices in which they are utilized. This study investigates how pi-pi interactions, notably arene-perfluoroarene (pi Hpi F) interactions, guide the crystal structures of boron subphthalocyanine (BsubPc) hybrid derivatives by leveraging the dual dipole moments inherent in F8BsubPcs and F8Bsub(Pc2-Nc1)s. We crafted a simple molecular design varying BsubPc-type hybrids by their axial moieties and number of peripheral arene sites while maintaining a consistent count of peripheral perfluoroarene (pi-hole) sites. The geometric analyses revealed that solid-state arrangements of perfluorinated BsubPc-type hybrids can be purposefully altered by introducing substituents that promote pi Hpi F stacking. We found that an additional fused benzene ring in the periphery introduced new stacking modes characterized by enhanced pi-pi overlap in F8Bsub(Pc2-Nc1) hybrids compared to F8BsubPcs, producing one-dimensional slip-stacked columns directed by strong-to-moderate pi Hpi F interactions. Incorporation of an axial phenol ligand in the F8Bsub(Pc2-Nc1) architecture further directed new stacking patterns, transforming the framework of arene-perfluoroarene interactions from their axially halogenated counterparts. Long-range packing motifs, Hirshfeld surfaces, various solvent growth methods, serendipitous ring-opened structures, and halogen bonding were examined to understand these pi Hpi F interactions further. This work realizes the control of BsubPc hybrid spatial arrangements through strategic pi-pi interactions and provides avenues for potentially improved electronic functionality via highly ordered close packing configurations.

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.

Understanding the degradation behaviour of organic photovoltaic (OPV) devices is an essential part to improve their stability prior to massive production. Accelerated aging can help to assess their stability and study the underlying degradation mechanisms of OPVs. Most studies focus on individual layers or a full device, and little is known about the role a pre-aged layer stack plays in the performance of a device. Herein, we report the investigation of the effects of pre-aging of multiple layers on the performance of OPVs. Instead of aging a single layer or an entire stack (sequential layers: ITO/PEDOT:PSS/MoOx/F-BsubPc/C60/BCP/Ag), our process involved aging the intermediate layer stack for 24 h after depositing a specific layer before continuing with the subsequent depositions to fully fabricate/manufacture OPVs. Aging was conducted under four controlled conditions considering parameters including moisture, gas type, and temperature in the absence of light according to the International Summit on Organic Photovoltaic Stability (ISOS) protocols. Short of PEDOT:PSS we found that multiple layers, being subjected to the parameters, resulted in a decline in OPV device performance after being fully manufactured. Device performance is evaluated based on short-circuit current density (Jsc), power conversion efficiency (PCE), and open-circuit voltage (Voc). Our analysis provides insight into the degradation mechanisms of layered/planar OPV structures and offers strategic guidance for optimizing fabrication processes, particularly during the layer deposition transitions. We recommend that during OPV vacuum deposited fabrication, intermediate layers should be protected from moisture, O2, high temperature, and even inert gases, preferably in a low-vacuum environment. Illustration of fabrication process of F-BsubPc/C60 device with pre-aged intermediate layer stack. image

The precise synthesis of subporphyrinoid hybrids with pi-expanded topologies and unique material properties plays a promising role in the design of functional macrocycles. Easy, selective, and controllable routes to boron subphthalocyanine-subnaphthalocyanine hybrids, Bsub(Pc3-p-Nc(p))s, are desirable for this purpose yet synthetically challenging due to random mixtures of C-s-, C-3v-, and, in some cases, C-1-symmetric compounds that form during traditional statistical mixed cyclotrimerizations. Herein, we addressed this issue by developing a sterically driven mixed cyclotrimerization with enhanced selectivity for the targeted C-s-symmetric hybrid and complete suppression of sterically crowded macrocyclic byproducts. This process, coupled with a rationally designed precursor bearing bulky phenyl substituents, enabled the synthesis and characterization of bay-position phenylated Ph-2-(R-p)(8)Bsub(Pc-2-Nc(1)) hybrids with halogens (R-p = Cl or F) in their peripheral isoindole rings. Reaction selectivity ranged between 59 and 72% with remarkable yields, significantly higher than that of conventional mixed cyclotrimerizations. These findings were augmented by theoretical calculations on precursor Lewis basicity as guiding principles into hybrid macrocycle formation. Additionally, the incorporation of unfused phenyl groups and halogen atoms into the hybrid framework resulted in fine-tuned optical, structural, electronic, and electrochemical properties. This straightforward approach achieved improved selectivity and controlled narrowing of the product distribution, affording the efficient synthesis of structurally sophisticated Bsub(Pc-2-Nc(1)) hybrids. This then expands the library of 3-dimensional pi-extended macrocycles for use in a range of applications, such as in optoelectronic devices with precisely tailored optical properties.

Ice buildup can significantly and negatively impact system performance in various industrial sectors, and has remained a persistent challenge for decades. Many compliant materials exhibit excellent de-icing performance but are easily eroded by impacts from supercooled water droplets, sand, dust, and debris. A composite panel inspired by animal skin, consisting of a facesheet protecting a nanofluid layer beneath, which exhibits durable anti-icing and tunable photothermal properties is proposed. The viscous liquid layer beneath the facesheet increases flexural rigidity, preventing large deflections and increasing deformation resistance, which alters ice's adhesion to the surface. The non-uniform fluid pressure exerted by the viscous nanofluid-filled composite panels facilitates ice detachment, resulting in ice adhesion strengths as low as tau(ice) approximate to 10 kPa. Further, by altering the fluid properties, different additional functionalities can be endowed to the system. Incorporating fumed silica in a fluid-filled composite panel results in rheopectic behavior, and this doubles their impact resistance when the shear thickening properties are properly tuned. Additionally, the combination of a transparent facesheet and a solar light absorbent nanofluid allows for tunable photothermal properties, further enhancing the anti-icing performance of the system. This durable and tunable nanofluid-filled composite panel shows great promise as a multifunctional de-icing material.

The formation mechanism of boron subphthalocyanines (BsubPcs)hasthus far evaded researchers, making it nearly impossible to accuratelyestimate the overall reaction enthalpy a critical metric fordetermining chemical process safety for scale-up. To address thisgap, reaction calorimetry was used to collect thermokinetic data fora 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(& UDelta;H-r) increased with increasing reaction temperature,from -244.6 kJ/mol-BBr3 at 25 & DEG;C to -332.7kJ/mol-BBr3 at 50 & DEG;C to -391.3 kJ/mol-BBr3 at 75 & DEG;C. However, this increase in the magnitude of & UDelta;H-r did not result in a noticeable increase in Br-BsubPcyield, achieving 50%, 49%, and 52% yields at 25 & DEG;C, 50 & DEG;C,and 75 & DEG;C, respectively. When the molar equivalence of BBr3 was increased by 1.5x at 25 & DEG;C, the magnitude of & UDelta;H-r increased slightly (-252.2 kJ/mol-BBr3), but the yield did not improve (47%). Therefore, furtherattempts were made to try and improve the yield of Br-BsubPc by increasingthe molar equivalence of BBr3. It was found that BBr3 equivalencies greater than 0.48 resulted in significant reductionsin Br-BsubPc yield. The & UDelta;H-r of the semibatch Cl-BsubPcprocess was -266.5 kJ/mol-BCl3 with a yield of 33%.These processes were assessed based on criticality criteria and wereboth found to be "Criticality Class 1", which is relativelysafe for scale-up. Based on the calorimetry measurements, preliminaryestimates for process conditions and reactor design for scale-up areprovided.

Conjugated macromolecules have a rich history in chemistry, owing to their chemical arrangements that intertwine physical and electronic properties. The continuing study and application of these systems, however, necessitates the development of atomically precise models that bridge the gap between molecules, polymers, and/or their blends. One class of conjugated polymers that have facilitated the advancement of structure-property relationships is discrete, precision oligomers that have remained an outstanding synthetic challenge with only a handful of reported examples. Here we show the first synthesis of molecular dyads featuring sequence-defined oligothiophene donors covalently linked a to small-molecule acceptor. These dyads serve as a platform for probing complex photophysical interactions involving sequence-defined oligomers. This assessment is facilitated through the unprecedented control of oligothiophene length- and sequence-dependent arrangement relative to the acceptor unit, made possible by the incorporation of hydroxyl-containing side chains at precise positions along the backbone through sequence-defined oligomerizations. We show that both the oligothiophene sequence and length play complementary roles in determining the transfer efficiency of photoexcited states. Overall, the work highlights the importance of the spatial arrangement of donor-acceptor systems that are commonly studied for a range of uses, including light harvesting and photocatalysis.

Triplet harvesting is a useful property that could enhance the performance of solar cells if applied in the right framework. There are currently few functional examples of organic solar cells (OSCs) capable of triplet harvesting, but materials are already under development. The improved current density output has already been realized, but the viability of working devices needs to be confirmed to advance this technology further. Here, we find that the outdoor stability of encapsulated devices can be improved significantly if triplet harvesting is enabled between the donor and acceptor. We compared the stability of pentacene/BsubPcs (boron subphthalocyanines) devices simultaneously and controlled the triplet harvesting capability by adjusting the peripheral chlorination on the BsubPcs. Pentacene/Cl-Cl12BsubPc devices which also exhibited the best triplet harvesting ability for this study experienced the least amount of degradation, not only was the stability improved when compared to other pentacene/BsubPc devices but these devices also had the highest stability of any that were tested including other singlet and triplet harvesting devices. This is promising for both the singlet fission donors and triplet harvesting acceptors involved and for triplet harvesting as a mechanism in totality. During this study, we also confirmed that some materials such as tetracene have insufficient thermal stability in devices. We also studied the relevant stability of single nanolayers of these materials. For example, single layer tetracene films seemed relatively stable without encapsulation even in harsh aging conditions but when incorporated into encapsulated OSC devices, the performance decreased quickly. Additional data acquired regarding tetracene also showed that even in the absence of light, OSC device performance decreased rapidly at elevated temperatures and may indicate that a nanomorphological change occurs; unless the nanomorphology can be passivated, we can conclude that tetracene may be difficult to incorporate into OSCs in the future.

The goal of this study was to develop mixtures of peripherally halogenated boron subphthalocyanines (BsubPcs) to explore these macrocycles as mixed alloys for applications within the organic electronic space. These halogenated BsubPc mixtures were synthesized by reacting mixtures of commercially available phthalonitriles, namely 4,5-dichlorophthalonitrile (Cl2-pn), 4,5-difluorophthalonitrile (F2-pn), tetrachlorophthalonitrile (Cl4-pn), and tetrafluorophthalonitrile (F4-pn), with boron trichloride (BCl[Formula: see text] to achieve mixed halogenation upon formation of the BsubPcs. More specifically, as named, Cl2-pn + F2-pn and Cl4-pn + F4-pn mixtures were used to form Cl-Cl[Formula: see text]F[Formula: see text]BsubPc and Cl-Cl[Formula: see text]F[Formula: see text]BsubPc, respectively. To establish a firm synthetic methodology, the reaction kinetics of forming the BsubPc mixtures from their respective phthalonitrile mixtures were compared to the kinetics of the standard procedures forming the individual BsubPcs, for example, Cl-Cl[Formula: see text]BsubPc from Cl4-pn. As we use BCl3 to form the BsubPcs, the axial bond is in general chloride, but we observed again random fluoride axial exchange, and therefore moved to the second step to have complete axial fluorination. Crude mixed halogenated BsubPcs were sublimed at high purities to enable physical characterization, including a study of UV-Vis absorption spectra differentiation, and cyclic (CV) and differential pulse voltammograms (DPV) electrochemical differentiation. We also did density functional theory (DFT) calculations for points of physical properties comparison. The comparison points are together with fully peripherally chlorinated Cl[Formula: see text]BsubPcs and fluorinated F[Formula: see text]BsubPcs. Given the outcomes, we foresee in future studies the ability to tune different ratios of peripherally halogenated BsubPc mixtures via synthetic tools, to enable tuning of the HOMO LUMO energy levels, which could consequently tune their application and performance in organic electronics.