Porphyrin-based Molecules Research Articles

Precision engineering of nano-assemblies in superfluid helium by the use of van der Waals forces

The ability to precisely engineer nanostructures underpins a wide range of applications in areas such as electronics, optics, and biomedical sciences. Here we present a novel approach for the growth of nanoparticle assemblies that leverages the unique properties of superfluid helium. Unlike viscous solvents at or near room temperature, superfluid helium provides an unperturbed and cold environment in which weak van der Waals interactions between molecular templates and metal atoms become significant and can define the spatial arrangement of nanoparticles. To demonstrate this concept, diol and porphyrin-based molecules are employed as templates to grow gold nanoparticle assemblies in superfluid helium droplets. After soft-landing on a solid surface to remove the helium, transmission electron microscopy (TEM) imaging shows the growth of gold nanoparticles at specific binding sites within the molecular templates where the interaction between gold atoms and the molecular template is at its strongest.

Porphyrin-Based Molecules in the Fossil Record Shed Light on the Evolution of Life

The fossil record demonstrates the preservation of porphyrins (e.g., heme) in organic sediments and the fossilized remains of animals. These molecules are essential components in modern metabolic processes, such as electron transport (cytochromes) and oxygen transport (hemoglobin), and likely originated before the emergence of life. The integration and adaptation of porphyrins and structurally similar molecules (e.g., chlorophylls) are key aspects in the evolution of energy production (i.e., aerobic respiration and photosynthesis) and complex life (i.e., eukaryotes and multicellularity). Here, we discuss the evolution and functional diversity of heme-bound hemoglobin proteins in vertebrates, along with the preservation of these molecules in the fossil record. By elucidating the pivotal role of these molecules in the evolution of life, this review lays the groundwork necessary to explore hemoglobin as a means to investigate the paleobiology of extinct taxa, including non-avian dinosaurs.

Porphyrin and doxorubicin mediated nanoarchitectonics of copper clusters: a bimodal theranostics for cancer diagnosis and treatment in vitro.

Nanoarchitectonics, an emerging strategy, presents a promising alternative for developing highly efficient next-generation functional materials. Multifunctional materials developed using nanoarchitectonics help to mimic biological molecules. Porphyrin-based molecules can be effectively utilized to design such assemblies. Metal nanocluster is one of the functional materials that can shed more insight into developing nanoarchitectonic materials. Herein, an inherently near-infrared (NIR) fluorescing copper nanocluster (CuC)-mediated structural assembly via protoporphyrin IX (PPIX) and doxorubicin (Dox) is demonstrated as the functional material. Dox-loaded porphyrin-mediated CuC assembly shows singlet oxygen generation and 66% drug release at 15 min. Furthermore, the efficacy of this material is tested for cancer diagnosis and bimodal therapeutic strategy due to the fluorescing ability of the cluster and loading of PPIX as well as the drug, respectively. The nanoarchitecture exhibits targeted imaging and 83% cell death in HeLa cells upon laser irradiation with 10 nmoles and 20 nmoles of PPIX and Dox, respectively.

The Influence of the Central Metal Ion on the Electronic and Photovoltaic Properties of Metalloporphyrins [M= Zn(II), Ni(II), Cu(II), Au(III)] Systems

Although the pioneering use of porphyrins in organic solar cells (OSCs) was disappointing as reported efficiencies were very low, the situation has changed over the last five years as Zn-porphyrins with ABAB structures linked to acceptor units through triple bonds have been applied as donors resulting in efficiencies of up to 12% in binary OSCs and more than 15% in ternary OSCs.The optical and electrochemical properties of porphyrins can be adjusted by molecular design and functionalization on the b or meso positions of the porphyrin ring as well as by introduction of different central metal ions. The choice of the centrally bounded metal cation within the porphyrin core plays an important role in the electronic properties allowing the modulation of the frontier orbital levels and thereby use the porphyrin-based molecule as donor or acceptor component of the device.Due to the high HOMO level of Zn-Porphyrin derivatives, the Voc of OSCs using this family of compounds are lower than 0.9 V limiting the PCE of devices.We have described that Ni-porphyrins derivatives allow the design of OSCs with voltage higher than 1V. These systems present slightly higher optical bandgaps but the deeper highest occupied molecular orbital (HOMO) energy level make available to reach good PCE values of the solar devices.While porphyrins and their derivatives have been extensively used as donor component in the BHJ active layer of OSCs, the investigation of porphyrin-based materials as electron acceptor is very limited. Recently, we designed a new A2-D-A1-D-A2 non fullerene small molecule acceptor (NFSMA) with broad absorption up to 920 nm and a great absorption coefficient where A1 core is Au(III) porphyrin. This molecule, when used in OSC with a polymer donor yielded a PCE=9.24%. Nevertheless, the use of other central metals such as Cu(II) in the porphyrin core has been scarcely used in OSCs, the studied devices presented low efficiencies (≤ 3%). These outcomes demonstrated that metalloporphyrins, which is different from Zn-porphyrins, also have great potential for the design of NFSMAs for efficient OSCs. Also, we have studied A-π-D-π-A small molecules based on Cu(II) Porphyrin, scarcely used in OSCs, presenting an ambipolar behaviour, as donor and as acceptor. Here, I´ll present our recent work in design, synthesis, and application of porphyrin-based small molecules with different central metal for highly efficient OSCs.References V. Cuesta, M. Vartanian, P. de la Cruz, R. Singhal, G. D. Sharma and F. Langa. J. Mater. Chem. A, 2017, 5, 1057.S. Arrechea, A. Aljarilla, P. de la Cruz, M. K. Singh, G. D. Sharma and F. Langa. J. Mater. Chem. C, 2017, 5, 4742.M. Vartanian, R. Singhal, P. de la Cruz, S. Biswas, G. D. Sharma and F. Langa. ACS Appl. Energy, Mater., 2018, 1, 1304.M. Vartanian, P. de la Cruz, F. Langa, S. Biswas and G. D. Sharma. Nanoscale, 2018, 10, 12100.M. Vartanian, R. Singhal, P. de la Cruz, G. D. Sharma and F. Langa. Chem. Commun., 2018, 54, 14144.V. Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma and F. Langa. ACS Appl. Mater. Interfaces, 2019, 11, 7216.Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma and F. Langa, ChemSusChem, 2021, 14, 3439.H. Dahiya, V. Cuesta, P. de la Cruz, F. Langa and G. D. Sharma ACS Appl. Energy Mater., 2021, 4, 4498. Figure 1

Manipulation of the Magnetic State of a Porphyrin-Based Molecule on Gold: From Kondo to Quantum Nanomagnet via the Charge Fluctuation Regime.

By moving individual Fe-porphyrin-based molecules with the tip of a scanning tunneling microscope in the vicinity of the elbow of the herringbone-reconstructed Au(111) containing a Br atom, we reversibly and continuously control their magnetic state. Several regimes are obtained experimentally and explored theoretically: from the integer spin limit, through intermediate magnetic states with renormalized magnetic anisotropy, until the Kondo-screened regime, corresponding to a progressive increase of charge fluctuations and mixed valency due to an increase in the interaction of the molecular Fe states with the substrate Fermi sea. Our study demonstrates the potential of utilizing charge fluctuations to generate and tune quantum magnetic states in molecule-surface hybrids.

Indacenodithiophene Bridged Dimeric Porphyrin Donor and Absorption Complementary Indacenodithiophene Acceptor for Nonfullerene Organic Photovoltaics

Porphyrins are one of the most promising materials for organic photovoltaics (OPVs) because of their easily tunable functional groups. Herein, we present the design and synthesis of two porphyrin-based small molecule donors, IDT-2TPE and TPE, in which two porphyrin units are bridged by an indacenodithiophene (IDT) diethynylene unit for the former and a single porphyrin monomer for the latter, and 3-ethylrhodanine units are then end-capped symmetrically by phenylenethynylene π-linkers. The porphyrin dimer IDT-2TPE exhibits outstanding red-shifted absorptions with a valley in both solution (400–800 nm) and film (400–900 nm), low-lying energy levels, and excellent thermal stability compared to the porphyrin monomer TPE due to the extended π-conjugation and increased rigidity with the IDT unit. Impressively, the device based on the IDT-2TPE donor and IDTCR nonfullerene acceptor shows a broad photoelectron response up to 1000 nm and a power conversion efficiency (PCE) of 10.41% at AM 1.5G. For comparison, the device based on the TPE donor and IDTCR acceptor has a much lower PCE of 4.22%. The much better performance of the device IDT-2TPE/IDTCR is attributed to its higher photocurrent generation and more favorable surface morphology with elevated charge carrier mobilities.

Humidity-Responsive Polymer Cushion-Supported Biomimetic Membrane: A Model System for X-ray Studies.

An effort aimed at replacing the conventional water column by a relative humidity (RH) environment for structural investigation of a soft polymer cushion-supported model phospholipid membrane has been reported. An RH-responsive well-hydrated polymer cushion layer capable of approximately 2-fold swellability under RH 96% has been employed for phospholipid model membrane fabrication. To validate the proposed method, supported lipid bilayers (SLBs) of phosphocholine and phosphoethanolamine were deposited and structurally characterized at molecular level by the X-ray scattering method. In addition, the molecular interaction of the porphyrin-based hemin molecule, having a drug-like structure, with the supported membrane has been studied for further validation. The swelling behavior of the polymer cushion has been studied at a range of RH values prior to the bilayer deposition. The RH environment, in comparison to the conventional water column, enhanced the dynamic range approximately by 100-fold and the structural resolution by 2-fold. Thus, the bilayer structural features can be assessed without being overwhelmed by the background signals from the traditional water column. This facilitates in extracting reliable layer parameters and exogenous molecule-induced minute changes from the model fit. The proposed method will have far-reaching implications in biosensor engineering, protein-lipid, and drug-lipid interaction studies, X-ray microscopy, imaging, and photon correlation spectroscopy studies from SLBs where acquiring sufficient scattered intensity is still a challenge. This study also predicts that lab-based rotating-anode X-ray instruments can potentially be an alternative to the hard-access synchrotron experiments on biomimetic membranes, keeping the dynamic range and structural resolution uncompromised.

Molecular Engineering of Low-Bandgap Porphyrins for Highly Efficient Organic Solarcells

Organic solar cells (OSCs) based on solution-processed bulk heterojunction (BHJ) active layers have emerged as promising solutions for the conversion of solar energy into electrical energy in building and indoor applications due to their unique advantages, such as being lightweight and semitrans-parent and the possibility of being processed by low-cost roll-to-roll methods. The BHJ active layer employed for OSCs consists of a blend of an electron-donating material and an electron-accepting material creating internal donor-acceptor heterojunctions, and their optical and electrochemical properties are very important for the realization of a high-power conversion efficiency (PCE).The optical and electrochemical properties of porphyrins can be adjusted by molecular design and functionalization on the b or meso positions of the porphyrin ring as well as by introduction of different central metal ions.Although the pioneering use of porphyrins in OSCs was disappointing, as reported efficiencies were very low;the situation has changed over the last five years as Zn-porphyrins with ABAB structures linked to acceptor units, having relatively long-lived singlet excited states, have been successfully used as donors or acceptors, resulting in increased efficiencies.Here, I´ll present our recent work in design, synthesis, and application of porphyrin-based small molecules for highly efficient OSCs with VOC>1V and PCE>15%.References V. Cuesta, M. Vartanian, P. de la Cruz, R. Singhal, G. D. Sharma and F. Langa, J. Mater. Chem. A,2017, 5, 1057. S. Arrechea, A. Aljarilla, P. de la Cruz, M. K. Singh, G. D. Sharma, F. Langa. J. Mater. Chem. C, 2017, 5, 4742. M. Vartanian, R. Singhal, P. de la Cruz, S. Biswas, G. D. Sharma and F. Langa, ACS Appl. Energy Mater. 2018, 1, 1304. M. Vartanian, P. de la Cruz, F. Langa, S. Biswas, G. D. Sharma. Nanoscale, 2018, 10, 12100.M. Vartanian, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, Chem. Commun, 2018, 54, 14144.V. Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, ACS Appl. Mater. Interfaces, 2019, 11, 7216 .Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, ChemSusChem 2021, 14, 3439.H. Dahiya, V. Cuesta, P. de la Cruz, F. Langa, G. D. Sharma ACS Appl. Energy Mater. 2021, 4, 4498.

Porphyrinic conjugated microporous polymer anode for Li-ion batteries

Porphyrin-based molecules have attracted considerable interests for using as anodes in Li-ion batteries, because of their large π-conjugated aromatic structures, abundant active sites with multi-electron redox activities, and narrow HOMO–LUMO gaps. Herein, a porphyrinic conjugated microporous polymer was prepared through the Sonogashira-Hagihara cross-coupling reaction of Br-functionalized porphyrinic monomer and alkynyl-based monomer. Due to the existence of abundant active sites, rich porosity, narrow bandgap, and inhibition of dissolution in electrolyte, this porphyrinic porous polymer can be used as anode material for Li-ion batteries, and achieves high specific capacity of 1200 mAh g−1 at 1 A g−1, and capacity retention of 242% after 5000 cycles at 3 A g−1. This excellent performance can bear comparison with that of the state-of-the-art organic anode materials. The ex situ X-ray photoelectron spectroscopy tests reveal all of the porphyrin center, benzene ring and alkynyl parts of the porous polymer can be acted as active sites for Li insertion during the cathodic process.

Highly Efficient (>15%) Organic Solar Cells Based on Porphyrins

The optical and electrochemical properties of porphyrins can be tailored by changing the central metal and functionalization of the periphery, being excellent candidates as donors for Organic Solar Cells (OSCs). In the early years, the PCE values of OSCs based on porphyrins were very low, but by structural modifications, we achieve efficiencies in the range of 15%. In this presentation, I´ll show our recent work in design, synthesis and application of A−π−D−π−A and D−π−A−π−D porphyrin-based small molecules for highly efficient OSCs.References V. Cuesta, M. Vartanian, P. d. l. Cruz, R. Singhal, G. D. Sharma and F. Langa, J. Mater. Chem. A, 2017, 5, 1057-1065.S. Arrechea, A. Aljarilla, P. de la Cruz, M. K. Singh, G. D. Sharma, F. Langa. J. Mater. Chem. C, 2017, 5, 4742.M. Vartanian, R. Singhal, P. de la Cruz, S. Biswas, G. D. Sharma and F. Langa, ACS Appl. Energy Mater. 2018, 1, 1304.M. Vartanian, P. de la Cruz, F. Langa, S. Biswas, G. D. Sharma. Nanoscale, 2018, 10, 12100-12018.M. Vartanian, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, Chem. Commun, 2018, 54,14144-14147.V. Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, ACS Mater. Interfaces, 2019, 11, 7216-7225.Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma, F.Langa ChemSusChem 2020 DOI: 10.1002/cssc.202002664. Figure 1

A recent overview of porphyrin-based π-extended small molecules as donors and acceptors for high-performance organic solar cells

Structural development of porphyrin-based small molecules as electron donors and electron acceptors leads to optimal photovoltaic performances, with PCEs of over 12% and 9.6%, respectively, in bulk-heterojunction organic solar cells.

Improving the Efficient of Porphyrin-Based Organic Solar Cell

The optical and electrochemical properties of porphyrins can be tailored by changing the central metal and functionalization of the periphery, being excellent candidates as donors for Organic Solar Cells (OSCs). In the early years, the PCE values of OSCs based on porphyrins were very low, but by structural modifications, we achieve efficiencies in the range of 9-10%. In this presentation, I´ll show our recent work in design, synthesis and application of A−π−D−π−A and D−π−A−π−D porphyrin-based small molecules for efficient OSCs (»10%). Figure 1. A−π−D−π−A and D−π−A−π−D porphyrin-based small molecules

Porphyrinoid-based photosensitizers for diagnostic and therapeutic applications: An update

Porphyrin-based molecules are actively studied as dual function theranostics: fluorescence-based imaging for diagnostics and fluorescence-guided therapeutic treatment of cancers. The intrinsic fluorescent and photodynamic properties of the bimodal molecules allows for these theranostic approaches. Several porphyrinoids bearing both hydrophilic and/or hydrophobic units at their periphery have been developed for the aforementioned applications, but better tumor selectivity and high efficacy to destroy tumor cells is always a key setback for their use. Another issue related to their effective clinical use is that, most of these chromophores form aggregates under physiological conditions. Nanomaterials that are known to possess incredible properties that cannot be achieved from their bulk systems can serve as carriers for these chromophores. Porphyrinoids, when conjugated with nanomaterials, can be enabled to perform as multifunctional nanomedicine devices. The integrated properties of these porphyrinoid-nanomaterial conjugated systems make them useful for selective drug delivery, theranostic capabilities, and multimodal bioimaging. This review highlights the use of porphyrins, chlorins, bacteriochlorins, phthalocyanines and naphthalocyanines as well as their multifunctional nanodevices in various biomedical theranostic platforms.

Structural Design of Porphyrins for Binary and Ternary Organic Solar Cells with High Efficiency and Low Energy Loss

Porphyrin-based molecules have been explored for a long time as the active materials in dye-sensitized solar cells achieving efficiencies as high as 13%. Nevertheless, until the last few years, this family of molecules has been scarcely explored as donor materials in bulk heterojunction (BHJ) organic solar cells (OSCs).Believing that porphyrin-based molecules should play a more important role in BHJ OSCs we started a few years ago a project in this field using a careful structural optimization. Here I´ll present our last results in this field using porphyrin-based molecules in binary and ternary OSCs, reaching efficiencies close to 10% with low energy loss.

Enhanced Performance of MSM UV Photodetectors by Molecular Modification of Gallium Nitride Using Porphyrin Organic Molecules

In this brief, we present a novel surface modification process for gallium nitride (GaN) epitaxial films leading to enhanced ultraviolet (UV) photodetection. The adsorption of a layer of thiol-functionalized porphyrin-based organic molecules on the GaN surface has been carried out. The effect of surface modification was seen in the form of a significant reduction in the surface potential of GaN by ~250 mV and five-fold enhancement in the near-band-edge photoluminescence intensity, both indicating surface passivation of GaN. Consequently, reverse current for Nickel (Ni) Schottky contacts on molecularly modified GaN was decreased by 3 orders of magnitude, in dark at room temperature. Upon illumination by UV light, Ni/molecular layer/GaN interdigitated structures showed considerably improved photodetector (PD) characteristics such as responsivity for the visible-blind spectral region, photo-to-dark current ratio, and UV-to-visible rejection ratio. Such metal-molecular layer semiconductor device structures can be useful for the fabrication of more efficient GaN-based UV PDs, mitigating the adverse effects of electronic surface states in these materials.

Cathode interlayer-free organic solar cells with enhanced device performance upon alcohol treatment

Solvent treatment was used to simplify the device structure and enhance the device performance of porphyrin-based small molecule solar cells.

Synthesis and Characterization of Oligothiophene-Porphyrin-Based Molecules That Can Be Utilized for Optical Assignment of Aggregated Amyloid-β Morphotypes.

Molecular tools for fluorescent imaging of protein aggregates are essential for understanding the significance of these pathological hallmarks in proteopathic neurodegenerative diseases, such as Alzheimer's disease. Here, we report the synthesis of a series of oligothiophene porphyrin hybrids, OTPHs, and the evaluation of these dyes for fluorescent imaging of beta-amyloid aggregates in tissue sections from a transgenic mouse model with Alzheimer's disease pathology. The OTPHs proved to be successful for spectral and lifetime imaging assessment of protein deposits and our findings confirm that the enhanced spectral range and distinct lifetime diversity of these novel tools allow a more precise assessment of heterogeneous amyloid morphology compared with the corresponding oligothiophene dye. In addition, the chemical identity of the porphyrin moiety, as well as the spacing between the two optical active moieties, influenced the OTPHs performance for fluorescent assignment of the protein deposits. We foresee that our findings will aid in the chemical design of dyes that can be utilized as optical tools for studying the polymorphic nature of protein aggregates associated with proteopathic neurodegenerative diseases.

Macroscopically Anisotropic Structures Produced by Light-induced Solvothermal Assembly of Porphyrin Dimers

Porphyrin-based molecules play an important role in natural biological systems such as photosynthetic antennae and haemoglobin. Recent organic chemistry provides artificial porphyrin-based molecules having unique electronic and optical properties, which leads to wide applications in material science. Here, we successfully produced many macroscopically anisotropic structures consisting of porphyrin dimers by light-induced solvothermal assembly with smooth evaporation in a confined volatile organic solvent. Light-induced fluid flow around a bubble on a gold nanofilm generated a sub-millimetre radial assembly of the tens-micrometre-sized petal-like structures. The optical properties of the petal-like structures depend on the relative angle between their growth direction and light polarisation, as confirmed by UV-visible extinction and the Raman scattering spectroscopy analyses, being dramatically different from those of structures obtained by natural drying. Thus, our findings pave the way to the production of structures and polycrystals with unique characteristics from various organic molecules.

Diketopyrrolopyrrole-Porphyrin Based Conjugated Polymers for Ambipolar Field-Effect Transistors.

Porphyrin-based molecules have been widely used in dye-sensitized solar cells and bulk heterojunction solar cells, but their application in field-effect transistors (FETs) is limited. In this work, two conjugated polymers based on diketopyrrolopyrrole and porphyrin units were developed for FETs. The polymers exhibit extra-low band gap with energy levels close to -4.0 eV and -5.0 eV due to the strong electron-donating and withdrawing ability of porphyrin and diketopyrrolopyrrole. With additionally high crystalline properties, ambipolar charge carrier transports with a hole mobility of 0.1 cm2 V-1 s-1 in FETs were realized in these polymers, representing the highest performance in solution-processed FETs based on porphyrin unit.

Modifying the Chemical Structure of a Porphyrin Small Molecule with Benzothiophene Groups for the Reproducible Fabrication of High Performance Solar Cells.

A porphyrin-based molecule DPPEZnP-BzTBO with bulky benzothiophene groups was designed and synthesized as an electron donor material for bulk heterojunction (BHJ) solar cells. The optimized devices under thermal annealing (TA) and then chloroform solvent vapor anneanling (SVA) for 80 s exhibited an outstanding power conversion efficiencie (PCE) of 9.08%. Contrasted with the smaller thienyl substituted analogues we reported previously, DPPEZnP-BzTBO-based BHJ solar cells exhibited a higher open circuit voltage due to the lower highest occupied molecular orbital energy level. The TA post-treatment of the active layers induced the formation of more crystallized components, and the subsequent SVA provided a driving force for the domain growth, resulting in more obvious phase segregation between the donor and the acceptor in nanoscale. Furthermore, the PCEs kept above 95% upon the further SVA treatment within the time range of 60 to 95 s probably because the bulky benzothiophene groups retard the too quick change of crystallinity, providing a wide processing window for the reproducible device fabrication.