Ferrocene is a versatile organic compound in organic electronics and biomedical applications owing to its oxidation stability and quick response to voltage. Nevertheless, ferrocene-appended organic compounds are seldom reported because of the incompatibility of design with redox materials, regioselectivity, intricate synthetic approaches, and poor yields. Hence, we have developed a corrole-linked ferrocene derivative (Cor-Fc-Cor) and studied its self-assembled nanostructures under stimuli. Differential pulse voltammetry and UV-visible absorption spectra reveal that Cor-Fc-Cor exhibits significant changes in oxidation and reduction potentials when applying the voltage of 0.7 V and 1.2 V, which reflects on variation in Soret and Q-bands when compared to neutral molecules. Subsequently, neutral and stimulated molecules exhibit H-type aggregates through the methanol vapour diffusion approach, and their microscopic data suggest that neutral molecules show a nanosphere, which transforms to the flake-type structures at stimuli of 0.7 V and 1.2 V. Interestingly, electrochemical impedance analyses demonstrate that the self-assembled nanostructures of neutral and stimulated Cor-Fc-Cor exhibit a semiconducting nature. Therefore, this work proposes that novel synthesis and well-defined nanostructures of low-bandgap ferrocene-appended corroles serve as potential candidates for future electronics and energy device applications.

Substituted naphthol derivatives have received significant attention due to their wide range of biological and pharmaceutical activities, and further extending the generation of naphthol with photoactive materials promotes optoelectronic applications. Nevertheless, the synthetic methodology of such materials hitherto unknown. In this study, we have adopted an efficient Friedel–Crafts reaction of ortho ‐alkynylnaphthols with N,N ‐disubstituted arylamines to generate arylamine‐appended β‐naphthol derivatives. This transformation features broad substrate scope, excellent yields, and high atom economy and the method was successfully adapted for late‐stage functionalization of biomolecules and drug molecules with excellent yields. Further, UV–vis absorption and emission studies reveal that these materials have shown visible range absorption and blue emission with a quantum efficiency of 10%. Lately, photo‐irradiation on arylamine leads to a charged state that facilitates the improvement of the electronic properties. Consequently, novel synthetic methodology of photoactive materials paves the way to generate new developments in the area of small molecule‐derived optoelectronics.

In this work, we have intended and synthesized two innovative dyes, LG-P7 and LG-P8, that significantly improve the efficiency of dye-sensitized solar cells (DSCs) under outdoor and indoor/ambient illuminations. These dyes (LG-P7 and LG-P8) are modified versions of our previously reported LG-P5 and LG-P6 dyes, with the addition of an ethynyl bridge to extend pi-conjugation of the dye molecules, contributing to enhanced light harvesting behaviour. Using the asymmetric dual species copper (II/I) redox electrolyte ([Cu(II)(dmp)(2)Cl](+)/[Cu(I)(dmp)(2)](+)) and co-sensitization with the metal-free organic XY1b dye, both LG-P7/P8 devices delivered a PCE of similar to 35 % under 1000 lx WW CFL illumination, comparable to typically used D35 co-sensitized devices. The impact of introduction of ethynyl linkage was more pronounced for the D-D-pi-A dyes where moving from LG-P5:XY1b to LG-P7:XY1b, the PCE improved from 21.44 % to 35.14 % under 1000 lx CFL illumination. At a lower illumination intensity of 700 lx, the XY1b co-sensitized LG-P7/P8 devices even demonstrated superior performance compared to D35:XY1b (32.84 +/- 0.37 %), with PCE of 33.95 +/- 0.37 % (LG-P7:XY1b) and 33.03 +/- 0.16 % (LG-P8:XY1b). The introduction of extended pi-conjugation in the LG-P7 and LG-P8 dyes, compared to the parent triphenylimidazole-phenothiazine dyes (LG-P5 and LG-P6), contributed to enhanced light harvesting behaviour as well as improved photovoltaic performance further demonstrating the significance of systematic structural modifications in sensitizers to realize superior indoor photovoltaic performance in DSCs.

Living polymerization offers an intriguing process to control the nanostructure's explicit size and shape of organic materials. Owing to their thermodynamic stability, organic sensitized materials are intricate to attain precise structures. Herein, the imidazole tethered triphenylamine and their terminals functionalized with amide and dodecyl chain (ITAAL) are reported to facilitate the thermodynamic stable 1D nanostructures and transform to 2D nanosheets upon light stimulation, an unprecedented phenomenon in the realm of triarylamines. Subsequently, kinetically controlled experiments reveal the transverse growth of bundled nanorods from ITAAL, while ITAAL •+ discloses the lateral growth of extended 2D nanosheets via homo‐seeding living polymerization, resulting in high electrical conductivity. Interestingly, seed ITAAL with a monomer of ITAAL •+ and perylene diimide leads to extended 1D and 2D nanostructures supporting hetero‐seeding polymerization, which paves the way to investigate the donor–acceptor derived heterostructures with controlled dynamics to promote the design of efficient photovoltaic devices.

Controlling the dimensionality of nanostructures made from self-assembled macrocyclic systems is tedious because they attain thermodynamic stability through the extended π-conjugated structure. Mainly, corrole-based macrocycles are challenging as they form structures that make it difficult to grow hierarchical assemblies. Herein, three tetraphenylethylene (TPE) appended corroles (1-TPE-Cor, 2-TPE-Cor and 3-TPE-Cor) were developed by substituting one, two or three TPEs at the meso phenyl positions of corroles. Detailed investigations revealed that each TPE substituent influences the molecule's planarity, resulting in significant variations in optical, self-assembly, and electronic properties in the three derivatives. One-dimensional (1D) nanotubes were observed through π-π stacking for 1-TPE-Cor, while 2D nanosheets and nanospheres were seen for 2-TPE-Cor and 3-TPE-Cor. Consequently, the electrical conductivity of 1D nanotubes is 10 times higher than for the 2D and 0D nanostructures. Each TPE substituent on corroles affects their aggregation dynamics and electronic properties, and this study promotes novel corrole-based macrocyclic groups, apart from porphyrin and phthalocyanine, utilizing supramolecular interactions, paving the way to diversification in the field of electronics.

Heterostructures comprise two or more different semiconducting materials stacked either as co-assemblies or self-sorted based on their dynamics of aggregates. However, self-sorting in heterostructures is rather significant in improving the short exciton diffusion length and charge separation. Despite small organic molecules being known for their self-sorting nature, macrocyclic are hitherto unknown owing to unrestrained assemblies from extended pi-conjugated systems. Herein, two near infrared region (NIR) active molecules comprised of porphyrin appended D-pi-D (1) and A-pi-A (2) have been reported to show the self-assembled 0D and 2D nanostructures via J-aggregates. Interestingly, the mixture of 1 and 2 reveals self-sorting at the molecular level promoting nanosphere and sheet structures which further rolled over to spheres through pi-pi stacking leading to core-shell type heterostructure. Consequently, electrical conductivity is 10 times higher than the individual assemblies due to excited state electron transfer from 1 to 2 in a mixture, confirmed by femto second-transient absorption spectroscopy and electrochemical impedance spectroscopy. These results suggest that controlling the self-sorted heterostructures fosters refining the electronic properties which pave the way for designing novel NIR-absorbed molecules for organic solar cells (OSCs).

Investigating the structure-property relationship in π-conjugated organic materials is crucial for designing efficient materials for diverse optoelectronic applications. Tailoring the molecular structure enables tuning the nonlinear optical (NLO) properties of π-conjugated systems. Herein, we report the synthesis, characterization, and photophysical properties of tetraphenylethylene (TPE)-substituted corroles in meso (meso-TPE-Cor) and beta position (β-TPE-Cor). The excited state dynamics, investigated using femtosecond transient absorption spectroscopy (fs-TAS) with excitation at the Soret band (400 nm), revealed an internal conversion in the 250-303 fs range, vibrational relaxation (VR) in 7.1-12.7 ps range, an intersystem crossing (ISC) in 0.94-1.05 ns range, and the triplet lifetime in 0.111-0.126 µs range. Comparatively, β-TPE-Cor exhibited faster ISC and VR than meso-TPE-Cor. Furthermore, the NLO properties of both the corroles were investigated using the femtosecond Z-scan technique. Both the corroles exhibited significantly strong NLO parameters, characterized by prominent three-photon absorption (3PA) coefficients (∼10-4 cm3/GW2), high nonlinear refractive index (n2 ∼10-14 cm2/W), and hyperpolarizabilities (γ ∼ 10-30 esu). We observed that substituting the same TPE substituent in the β position demonstrated better NLO properties. Furthermore, as a proof-of-concept application, we investigated the optical limiting onset threshold of both the corroles, which exhibited superior performance compared to previously reported organic materials, highlighting its application in various photonic devices.

Self-assembly of two similar porphyrin derivatives leads to long axial nanofibers but their mixture results in short nanorods comprising narcissistic self-sorted structures with transitional electrical conductivity.

This study employs femtosecond transient absorption spectroscopy to investigate the rapid dynamics of excited state carriers in three metalated porphyrin-naphthalimide (PN) molecules and one free-base molecule. The dynamics of electron...

Indoor photovoltaics has received much attention in recent years mainly because of significances in human daily life for small scale device applications such as Internet of Things (IoT), remote sensors, actuators, and communication devices. Among various generations of photovoltaics, perovskite solar cells (PSCs) are found to be best suitable for indoor applications due to their easy to fabricate both on glass and flexible substrate, low-cost process and dispenses efficient power conversion efficiencies. PSCs have crossed the device efficiency of 25 % under AM 1.5G conditions and crossed the power conversion efficiency of 40 % under low-light/artificial light conditions. Therefore, there will be lot of attention on indoor perovskite photovoltaics (iPPV) in recent times towards many small device applications. The main focus of the review is to discuss recent developments in iPPVs for lead and lead-free perovskites, challenges, future direction and market opportunities.

An aryne annulation strategy for the synthesis of fused carbazoles is developed using indolyl beta-ketonitrile in a cascade manner. The reaction sequence involves aryne-mediated [2 + 2] cycloaddition cleavage and intramolecular Michael addition, followed by oxidation under transition-metal-free reaction conditions. Subsequently, conversion of benzo[b]carbazole-6-carbonitrile to carbazole quinone is observed upon prolongation of the reaction time. Furthermore, these materials exhibit high quantum efficiency, which promotes the light-emitting diode applications.

An efficient functionalization of tyrosine residues in phenolic regions is achieved under metal-free conditions. The strategy involves the conversion of a tyrosine residue to 4-amino phenylalanine or 4-amino-3-methoxy phenylalanine in short peptides through a controlled oxidative dearomatization. This transformation is achieved in one pot with good yields and excellent regioselectivity. Consequently, the self-assembly of the peptide compounds has been studied at the nanoscopic level before and after functionalization. The results suggest that the peptide derivatives comprising amide groups promote intermolecular H-bonding interactions and the difference in -OH and -NH2 functional groups is found to be responsible for the morphological changes. Morphological transitions from 1D nanowires to 2D nanosheets were observed during functional group modification. An efficient metal-free method for the conversion of tyrosine to 4-amino-3-methoxy phenylalanine or 4-amino phenylalanine has been developed in one pot via controlled oxidative dearomative functionalization.

Donor-acceptor in linear π-conjugated systems elicits the intramolecular charge transfer which improves the optical and electronic characteristics. Nevertheless, linear arrangement of electron donor and acceptor finely tune the charge or electron transfer process divulges the device performance. Therefore, molecular engineering of appropriate D-A with precise spacer is indeed challenging. Herein, we synthesized two bispyrene derivatives and attached with benzothiadazole and phenyl group through imidazole spacer (PyBTD and PyBz). PyBTD has shown solvatochromism demonstrates the intramolecular charge transfer (ICT) from pyrene to benzothiadiazole while PyBz remains as pristine spectra. Microscopic images reveal that network-type structures for PyBTD and elongated nanorods from self-assemblies of PyBz. Subsequently, host-guest interactions suggest that C60 was encapsulated in concave shaped bispyrene controls their crystallinity in nanostructures leads short nanosheets. Impedance analyses depict ICT assisted nanowires facilitate improved conductivity than host-guest complex. Therefore, imidazole spacer between D-A systems paves the way to design such type of molecules for future generated optoelectronics.

The diverse applications such as all-optical switching, modulation, OR-logic gates, and photonic diode interconnected with the fundamental of nonlinear optics has been demonstrated in porphyrin–napthalimide molecules using SSPM and XPM methods.

Increasing energy consumption of non-renewable resources escorted by enduring hasty growth of population and industrial parks researchers have immense attention in the advancement of renewable and sustainable energy technologies. Dye-sensitized solar cells (DSSCs) are considering a well source for clean and renewable energy due to their ease of fabrication, low-cost and minimal environmental impacts. The photosensitizer or dye is one of the chief components in DSSC and plays a pivotal role to initiate the electrochemical process for electricity generation by harvesting the sunlight. Various sensitizers viz., metal-free, Ru-metal complexes and tetra pyrrolic macrocyclic, porphyrins having strong absorption in the visible region have studied for DSSC applications. These sensitizers have tunable photophysical, electrical and electrochemical properties and ease of structural modification. With these advantages, donor-π-acceptor (D–π–A) structural concept based metal-free organic dyes, porphyrins have exceeded 13% power conversion efficiency. Among the various donors, phenothiazine possesses strong electron donating character and non-planar butterfly conformation linked to Rutheniu(II) polypyridyl complexes, metal-free organic, and porphyrin macrocyclic forms large π conjugated system that can retard the molecular aggregation as a result enhance the photovoltaic performance. Thus, the structural features of phenothiazine tethered dyes demonstrate high photovoltaic performance (12%), even superior than the commercial ruthenium complex (N719). This review summarized topical advancements in the phenothiazine tethered dyes and concentrates on the correlation between molecular structures and the photovoltaic performances for achieving the efficient DSSC.

•We dessigned and synthesised D-π-D porphyrin molecules via low-temperature high yield chemical process.•The copper porphyrin molecules exhibited higher charge carrier conductivity compare with other porphyrins.•The dopant free copper porphyrin HTM showed better performance than remaining two HTMs.•New HTMs are thermally stable.

Metal halides have been explored with the aid of strong photoluminescence for optical and optoelectronic applications. However, the preparation of lead (Pb)-free solid-state emitters with high photoluminescence quantum yields (PLQYs) and tunable emission remains exceptionally challenging. Herein, we report metal ion (Cu(I), Mn(II), and Sn(II))-doped Cs3ZnI5 single crystals that are primary color (violet, green, and orange/red) emitters with extremely high PLQYs. Whereas the Mn-doping leads to bright green emissions with 100% PLQY, the Cu- and Sn-doping give rise to blue and red emissions with PLQYs of 57 and 64%, respectively. Interestingly, higher Mn doping results in white light emissive crystals as a side product, which are found to be Mn-doped CsI single crystals. The bright white light emissive crystals can be synthesized in a pure form in large quantities and exhibit a high color rendering index (CRI) of 78 and CIE coordinates of (0.30, 0.38), which are close to daylight conditions. To the best of our knowledge, this is the first demonstration of white light emission from a complete inorganic system. Importantly, the single crystals of all colors exhibit high long-term stability as their PLQY remains unchanged even after 2 months of preparation, and are thermally stable up to 600 °C.

Porphyrin applications are primarily related to electronic transitions across a broad spectrum. In this context, understanding the excited state electron dynamics is necessary in such chromophores. Herein, we report the ultrafast photophysical characterization of one free base and three transition metallated porphyrin - napthali-mide based donor -acceptor systems (PN-Fb, PN-Ni, PN-Cu, and PN-Zn) in dichloromethane (DCM) solution using transient absorption spectroscopy (TAS) in the spectral range of 430-780 nm by the Soret band excitation at 400 nm. The different rate constants were extracted using a target model analysis of the collected transient absorption spectra and established a consistent photophysical model of molecular excited state population re-laxations. The photophysical model consisted of the following various processes: (a) internal conversion in the range of 215-400 fs, (b) vibrational relaxation in the range of 1.35-62 ps, and (c) singlet state relaxation times in the range of 0.17-2.06 ns, and finally (d) 0.03-10 mu s was attributed to the triplet state lifetimes. We have also measured the nonlinear optical properties of these molecules by the open and closed aperture Z-scan studies, which was carried out by 800 nm, 70 fs photoexcitation. The theoretical fittings to the experimental data resulted in an effective three-photon absorption coefficient and positive nonlinear refractive index. Further, from the Z -scan data, the second hyperpolarizability of the molecules was calculated, and the values were 10-31 esu. Additionally, complete optimization of individual structures and construction of these PN systems was achieved using density functional theory (DFT) calculations and the obtained results were found to be consistent with the experimental observations.

Tuning the crystallinity in self-assembled nanostructureshas asignificant impact on the electronic properties. Although severalapproaches have been adopted for organic pi-conjugated systemsto generate the amorphous to crystalline structures, the bulky structureof extended macrocyclics is hitherto unknown. Herein, we have developedthree symmetric freebase and metallo substituted porphyrin appendedbispyridylquinoxalines (P-Fb-DPQ, P-Cu-DPQ andP(Zn)-DPQ) in which copper metalated P-DPQ exhibits crystallinephase transitions under light stimuli. Notably, light irradiated P-DPQderivatives undergo a protonation, demetalation, and anion bindingmechanism, resulting in the formation of self-assembled open, closed0D nanospheres together with 2D nanosheets via methanol vapor diffusionapproach. Interestingly, light stimulation regulates the morphologyfrom 0D nanosphere to 2D nanosheets in P-Cu-DPQ and H+[P-Cu-DPQ(Cl)](-), which promotesthe amorphous to crystalline nature. Consequently, the bulk conductivityof 2D nanosheets exhibits similar to 32 mS cm(-1), andit is remarkably 10(2) times higher than 0D nanospheres.Thus, these results promote that the stimuli responsive metallo substitutedmacrocyclic systems is a significant initiative to manipulate theelectronic properties in organic electronics.

Spatial self-phase modulation (SSPM) is a nonlinear optical (NLO) coherent interaction between light and matters. The phase gets self-modulated due to the change of nonlinear refractive index through the nonlinear Kerr effect and produce diffraction rings at the far fields. [1] Porphyrins are the organic molecules with π-conjugation electron rich systems, they possess delocalized electric field distribution and large dipole moments that lead to have significant electrical polarization, which is a profit for higher NLO response. These molecules have various application in photovoltaics, photonics, optoelectronics, etc. [2, 3] Herein, we report the NLO properties of four metalated porphyrin-napthalimide based donor-acceptor systems named as PN-Zn, PN-Ni, PN-Cu, and PN-Fb using SSPM and continuous wave (CW) Z-scan method for exploring various optoelectronic applications like optical limiting, optical switching, and logic gates, etc.