@article{naik_elias_keremane_babu_abdellah_2024, title={Metal-Free Organic Dyes for NiO-Based Dye-Sensitized Solar Cells: Recent Developments and Future Perspectives}, ISSN={["2194-4296"]}, DOI={10.1002/ente.202301666}, abstractNote={The increasing global demand for energy and growing environmental concerns emphasize the crucial role of solar energy as a sustainable and nondepletable resource. Solar cells, particularly dye‐sensitized solar cells (DSSCs), have gained prominence due to their efficient conversion of solar power, ecofriendly manufacturing processes, and noteworthy stability. Current research in sustainable energy focuses on transitioning from metal‐based to metal‐free organic materials. Tandem solar cells, combining n‐type and p‐type semiconductors sensitized with diverse photoactive dyes, show potential to surpass thermodynamic limits in photon conversion efficiency. Notably, the exploration of n‐type DSSCs as photoanodes in tandem architectures is promising. However, the absence of efficient p‐type photoactive cathodes remains a significant obstacle. Global research efforts are dedicated to addressing charge recombination issues in NiO‐based devices to enhance the efficiency of p‐type DSSCs. The success of any DSSC hinges on the selection of dyes/sensitizers with suitable anchoring groups, wide absorption in the visible–NIR region, and a high extinction coefficient. This article comprehensively reviews advancements in developing highly efficient p‐type sensitizers, emphasizing their pivotal role in unlocking the full potential of tandem solar cells.}, journal={ENERGY TECHNOLOGY}, author={Naik, Praveen and Elias, Liju and Keremane, Kavya S. and Babu, Dickson D. and Abdellah, Islam M.}, year={2024}, month={Apr} }
 @article{comprehensive investigation of the potential of hydrazine and its  derivatives for the synthesis of various molecules with biological  activity_2023, url={https://www.iscientific.org/wp-content/uploads/2023/10/41-IJCBS-23-24-4-42-done.pdf}, journal={International Journal of Chemical and Biochemical Sciences}, year={2023}, month={Oct} }
 @article{abdellah_eletmany_el-shafei_2023, title={Exploring the impact of electron acceptor tuning in D-π-A′-π-A photosensitizers on the photovoltaic performance of acridine-based DSSCs: A DFT/TDDFT perspective}, volume={35}, ISSN={2352-4928}, url={http://dx.doi.org/10.1016/j.mtcomm.2023.106170}, DOI={10.1016/j.mtcomm.2023.106170}, abstractNote={Nine novel organic molecules with D-π-A′-π-A motifs, designated as (Ac-T-Qs-T-CA) and (Ac-T-Bx-T-CA), were proposed as potential photosensitizers for use in dye-sensitized solar cells (DSSCs). These novel organic photosensitizers are comprised of an acridine electron donor (Ac) and a thiophene π-spacer (T), while the electron acceptor unit (A′) is either a substituted quinoxaline (Qs) or a benzo[2,5]diazole-1-heteroatom (Bx), and the anchoring group (A) is 2-cyanoacrylic acid (CA). The influence of electron acceptor (A′) moieties on the electronic, photophysical, thermodynamic and photovoltaic properties of the photosensitizers was analyzed using DFT and TD-DFT calculations. The MM3 force field and CONFLEX conformational search methods were employed to study all possible structural conformations of the photosensitizers. The goal was to identify the lowest energy conformer and gain a better understanding of how the structure conformation and torsional angles of (Ac-T-Qs-T-CA) and (Ac-T-Bx-T-CA) compared to the reference photosensitizer RK1 affect electron injection ability and overall performance of DSSCs. The thermodynamic analysis revealed that the photosensitizers (Ac-T-Q2,3-diOMe-T-CA) and (Ac-T-BtA-T-CA), which contain a 2,3-dimethoxyquinoxaline (Q2,3-diOMe) and a benzo[d][1,2,3]triazole (BtA) acceptor moieties, respectively, exhibit a noteworthy enhancement in their electron-injection free energy (ΔGinj) and a reduction in their recombination-free energy (ΔGrec) values, leading to an improvement in the overall photovoltaic properties of the solar cell when compared to the other photosensitizers. The photovoltaic characteristics of the photosensitizers showed that the photosensitizer (Ac-T-Q2,3-diOMe-T-CA) demonstrated the highest values of open-circuit photovoltage (Voc = 1.41 eV) and light harvesting efficiency (LHE = 0.80 eV) compared to the other (Ac-T-Qs-T-CA) photosensitizers. Similarly, (Ac-T-BtA-T-CA) photosensitizer demonstrated the highest Voc (1.08 eV) and LHE (0.75 eV) among (Ac-T-Bx-T-CA) photosensitizers. The photovoltaic performance of these new photosensitizers outperformed the reference RK1 photosensitizer, which only achieved a Voc of 1.2 eV and LHE of 0.61 eV. Finally, the electronic structures and optical properties of photosensitizers adsorbed on the TiO2 surface were studied to provide more accurate information about their adsorption on the semiconductor surface.}, journal={Materials Today Communications}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Eletmany, Mohamed R. and El-Shafei, Ahmed}, year={2023}, month={Jun}, pages={106170} }
 @article{abdellah_yildirim_el-shafei_2023, title={Low-cost novel X-shaped hole transport materials for efficient perovskite solar cells: Molecular modelling of the core and schiff base effects on photovoltaic and photophysical properties}, volume={296}, ISSN={["1879-3312"]}, url={https://doi.org/10.1016/j.matchemphys.2022.127188}, DOI={10.1016/j.matchemphys.2022.127188}, abstractNote={Eight molecules with D-π-D molecular motifs coded HTM(1-4)a,b were designed as efficient symmetric hole transporting materials for perovskite solar cells. These HTMs are composed of different core moieties, such as spiro [fluorene-9,9′-xanthene]-diol (SFO), spiro [fluorene-9,9′-xanthene]-dimethoxy (SFM), benzo [c][1,2,5]thiadiazole (BTD), and biphenyl (BP) and are gaining lot of attention because of their low-cost, reproducible electrical and optical properties in device performance. Detailed information about the energetic of molecular levels (GSOP/ESOP), first singlet excitation energy (E0-0), equilibrium molecular geometry, charge separation, charge transfer, reorganization energies, polarizability and hyperpolarizability, density of states (DOS), solubility and stability of these molecules was attained by systematically performing molecular modeling calculations using density functional theory (DFT) and time dependent-DFT calculations utilizing hybrid density functional B3LYP using the basis set 6–31g(d,p) level of theory as a successful method for predicting the photophysical and photovoltaic properties of these conjugated systems. The results showed that not only the core moieties, but also Schiff-base linkage extended conjugation, have an effect on the photophysical and photovoltaic properties of the proposed HTMs. It was demonstrated that HTMs incorporating SFO (HTM1a,b), SFM (HTM2a,b), and BP (HTM4a,b) achieved better charge transport, high stability values (η a = 2.11–2.40 eV), low electron-hole binding energy (Eb = 0.16–0.21 eV) than HTM3a,b with BTD core, which improves hole mobility and decreases recombination, all of which improved device photocurrent, which can be attributed to the extended π-conjugation in SFO, SFM and BP cores. These findings are strikingly similar to those of Spiro-OMeTAD (η a = 2.45 eV, Eb = 0.16 eV), indicating that these HTMs are promising candidates for efficient and cost-effective PSCs. Interestingly, when the stability of HTM(1-4)a and HTM(1-4)b was compared, it was clear that HTM(1-4)a has lower stability than HTM(1-4)b, which could be attributed to the presence of Schiff base CN bonds in HTM(1-4)b, which reduces the molecules stability when compared to HTM(1-4)b, owing to a strong C–C linkage. Meanwhile, HTM(1-4)a outperforms HTM(1-4)b in terms of electronic performance and hole mobility.}, journal={MATERIALS CHEMISTRY AND PHYSICS}, author={Abdellah, Islam M. and Yildirim, Erol and El-Shafei, Ahmed}, year={2023}, month={Feb} }
 @article{eletmany_aziz albalawi_alharbi_elamary_harb_selim_sayed abdelgeliel_hassan_abdellah_2023, title={Novel arylazo nicotinate derivatives as effective antibacterial agents: Green synthesis, molecular modeling, and structure-activity relationship studies}, volume={27}, ISSN={1319-6103}, url={http://dx.doi.org/10.1016/j.jscs.2023.101647}, DOI={10.1016/j.jscs.2023.101647}, abstractNote={A series of novel arylazo nicotinates compounds, denoted as (3a-k and 5a-d) were synthesized and characterized through the reaction of 3-oxo-arylhydrazonals with various active methylene nitriles using microporous zeolite as a green catalyst. The structure of the newly prepared heterocycles was determined using various spectral techniques such as MS, IR, NMR, and elemental analysis. The antibacterial activity of these compounds against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) was evaluated, and it was found that all arylazo nicotinate compounds were highly effective against both gram-negative (E. coli) and gram-positive (B. subtilis) bacterial strains. The efficacy of the developed arylazo nicotinate derivatives as antimicrobial agents against E. coli and B. subtilis was evaluated using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. Density-functional theory (DFT) was employed to investigate the structure–activity relationships of recently synthesized compounds. Gaussian 09 software was utilized to compute various molecular properties, including the distribution of frontier molecular orbitals (FMO), the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), the energy gap (Eg), as well as several biological activity descriptors such as ionization potential (IP), electron affinity (EA), chemical potential (μ), chemical hardness (η), electronegativity (χ), global softness (S), and electrophilicity index (ω). The results of the FMO calculations revealed that the arylazo nicotinates had effective charge separation and distinct HOMO/LUMO energy levels for each compound, as reflected by the different Eg values. The Eg values were found to have a strong correlation with the antibacterial efficacy against E. coli and B. subtilis. The highest and lowest efficacy among the molecules (3a-k) were observed for compounds 3b (Eg = 3.36 eV) and 3 k (Eg = 2.27 eV), respectively, while the highest and lowest efficacy among the molecules (5a-d) were observed for compounds 5d (Eg = 3.33 eV) and 5c (Eg = 2.94 eV), respectively.}, number={3}, journal={Journal of Saudi Chemical Society}, publisher={Elsevier BV}, author={Eletmany, Mohamed R. and Aziz Albalawi, Marzough and Alharbi, Reem A.K. and Elamary, Rokaia B. and Harb, Abd El-Fattah A. and Selim, Moghraby A. and Sayed Abdelgeliel, Asmaa and Hassan, Entesar A. and Abdellah, Islam M.}, year={2023}, month={May}, pages={101647} }
 @article{abdellah_eletmany_abdelhamid_alghamdi_abdalla_elhenawy_latif_2023, title={One-Pot Synthesis of Novel Poly-Substituted 3-Cyanopyridines: Molecular Docking, Antimicrobial, Cytotoxicity, and DFT/TD-DFT Studies}, volume={1289}, ISSN={0022-2860}, url={http://dx.doi.org/10.1016/j.molstruc.2023.135864}, DOI={10.1016/j.molstruc.2023.135864}, abstractNote={Novel pyridine-3-carbonitrile derivatives, denoted as (4a-j), were synthesized using a convergent synthetic approach that involved a one-pot four-component reaction. This was achieved by utilizing a combination of various aromatic aldehydes, acetophenone derivatives, malononitrile, and four different sodium alkoxide solutions. The synthesized compounds were characterized using various spectroscopic techniques such as IR, 1HNMR , 13CNMR , and elemental analysis. Molecular docking simulations were employed to investigate the binding affinity of compounds (4a-j) towards two proteins, DHFR and HT-hTS. The results revealed that 4-(4-chlorophenyl)-2-ethoxy-6-phenyl-pyridine-3-carbonitrile (4a) compound exhibited the highest binding affinity score (ΔG = -8.06 Kcal/mol) upon docking into the active site of DHFR, while 2-(4-nitrophenyl)-6-(4-chlorophenyl)-4-ethoxy-pyridine-3-carbonitrile (4d) compound displayed the strongest binding affinity score (ΔG = -4.17 Kcal/mol) when docked to the active site of HT-hTS. These results were supported by the cytotoxic activity of selected compounds (4a, 4b, 4e, and 4 h) against human cancer cell lines (MCF7, HT29, and A2780) as well as normal human fetal lung fibroblast (MRC5) using MTT assay. The cytotoxicity analyses revealed that compound (4a) displayed cytotoxic activity against all cancer cell lines, particularly human colorectal carcinoma (HT29) with an IC50 value of 2.243±0.217 μM, which is lower than that of the reference drug (Doxorubicin) with an IC50 value of 3.964±0.360 μM. Furthermore, compound (4a) exhibited a lower cytotoxic effect on normal human fetal lung fibroblast (MRC5) with an IC50 value of 2.222±0.137 μM, as compared to the IC50 value of the reference drug (Doxorubicin) which was 2.476±0.033 μM. The antimicrobial activity of selected compounds such as (4a, 4c, and 4f) was also evaluated against a panel of microorganisms, including two gram-positive strains (Staphylococcus aureus and Enterococcus faecalis) and two gram-negative strains (Escherichia coli and Pseudomonas aeruginosa). The zone of inhibition and minimum inhibition concentration (MIC) demonstrated the potency of these compounds. Specifically, compounds 4-(4-chlorophenyl)-2-ethoxy-6-phenyl-pyridine-3-carbonitrile (4a) and 4-(4-methoxyphenyl)-2‑methoxy-6-(4-nitrophenyl)-pyridine-3-carbonitrile (4f) exhibited MIC of 0.013 µM against E. coli strains, which is comparable to that of the reference drug amoxicillin (MIC=0.01 µM). Finally, Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TDDFT) studies were performed on compounds (4a-j) to obtain a more comprehensive understanding of the structure-activity relationship and solvatochromic behavior of these molecules. Overall, the results suggest that compound (4a) could potentially serve as a promising cytotoxic and antibacterial agent with a better safety profile and reduced side effects on normal cells.}, journal={Journal of Molecular Structure}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Eletmany, Mohamed R. and Abdelhamid, Antar A. and Alghamdi, Haitham S. and Abdalla, Ashraf N. and Elhenawy, Ahmed A. and Latif, Fawy M. Abd El}, year={2023}, month={May}, pages={135864} }
 @article{barqi_abdellah_eletmany_ali_elhenawy_abd el latif_2023, title={Synthesis, Characterization, Bioactivity Screening and Computational Studies of Diphenyl−malonohydrazides and Pyridines Derivatives}, volume={8}, ISSN={2365-6549 2365-6549}, url={http://dx.doi.org/10.1002/slct.202203913}, DOI={10.1002/slct.202203913}, abstractNote={Abstract}, number={2}, journal={ChemistrySelect}, publisher={Wiley}, author={Barqi, Mashael M. and Abdellah, Islam M. and Eletmany, Mohamed R. and Ali, Nada M. and Elhenawy, Ahmed A. and Abd El Latif, Fawy M.}, year={2023}, month={Jan} }
 @article{towards sustainable management of insect pests: protecting food security through ecological intensification_2023, url={https://www.iscientific.org/wp-content/uploads/2023/10/42-IJCBS-23-24-4-43-done.pdf}, journal={International Journal of Chemical and Biochemical Sciences (ISSN 2226-9614)}, year={2023}, month={Oct} }
 @article{abdellah_zaky_eletmany_2023, title={Visible light photoredox catalysis for the synthesis of new chromophores as co-sensitizers with benchmark N719 for highly efficient DSSCs}, volume={145}, ISSN={["1873-1252"]}, url={https://doi.org/10.1016/j.optmat.2023.114454}, DOI={10.1016/j.optmat.2023.114454}, journal={OPTICAL MATERIALS}, author={Abdellah, Islam M. and Zaky, Omniya S. and Eletmany, Mohamed R.}, year={2023}, month={Nov} }
 @article{dft, td-dft and biological activity studies of some maleanilic acid derivatives ligands and their organometallic complexes_2021, url={https://doi.org/10.56042/ijca.v60i12.55295}, DOI={10.56042/ijca.v60i12.55295}, abstractNote={This study is a complementary study to our previous study that included the synthesis and characterization of some maleanilic acid derivatives ligands (L 1-4 ) and their metal carbonyl complexes (2-4) a-d as effective compounds for cancer cell inhibition against three cancer cell lines: HCT-116 (colon cancer), HepG-2 cells (Hepatocellular cancer) and MCF-7 (breast cancer). The activity data manifested that p-nitrophenyl maleanilic acid ligand (L2) and its chromium complex (2b) showed higher inhibitory than the other complexes against the tested cancer cells. Additionally, DFT and TD-DFT studies were performed to investigate their frontier molecular orbital (FMO), optical properties, and the correlation between the structure and biological activity. The calculated optical energy gap ( E g ) was in the range of 1.78- 2.13 eV, and electron cloud delocalization of HOMO/LUMO levels revealed that all complexes show effective charge separation. DFT results show a great relation between E g values of the carbonyl complexes and their experimental biological activity. Where it was obvious that complex ( 2b ) with the lowest ( E g ) value exhibits the highest inhibition potency against cancer cells. In contrast, complex ( 2d ) with the highest ( E g ) value exhibits the lowest inhibition potency. These results translate the reverse relationship between E g values of the complexes and the inhibition potency against cancer cells.}, journal={INDIAN JOURNAL OF CHEMISTRY- SECTION A}, year={2021}, month={Dec} }
 @article{abdellah_chowdhury_lee_islam_nazeeruddin_graetzel_el-shafei_2021, title={Facile and low-cost synthesis of a novel dopant-free hole transporting material that rivals Spiro-OMeTAD for high efficiency perovskite solar cells}, volume={5}, ISSN={["2398-4902"]}, url={https://doi.org/10.1039/D0SE01323D}, DOI={10.1039/d0se01323d}, abstractNote={A Spiro fluorene-based dopant-free hole-transporting material named Spiro-IA has been designed and developed as an alternative to commercial Spiro-OMeTAD for more effective perovskite solar cells (PSCs).}, number={1}, journal={SUSTAINABLE ENERGY & FUELS}, publisher={Royal Society of Chemistry (RSC)}, author={Abdellah, Islam M. and Chowdhury, Towhid H. and Lee, Jae-Joon and Islam, Ashraful and Nazeeruddin, Mohamad K. and Graetzel, Michael and El-Shafei, Ahmed}, year={2021}, month={Jan}, pages={199–211} }
 @article{koraiem_abel aal_abdellah_2020, title={Aqueous & microwave synthesis & spectral behaviour of some selected photosensitizer zero-methine & self-assembly mero cyanine dyes}, volume={8}, ISSN={2320-9186}, number={8}, journal={GSJ Journal}, author={Koraiem, A.I.M. and Abel Aal, R.M. and Abdellah, I.M.}, year={2020} }
 @article{abdellah_el-shafei_2020, title={Efficiency enhancement of ruthenium-based DSSCs employing A–π–D–π–A organic Co-sensitizers}, volume={10}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/d0ra03916k}, DOI={10.1039/d0ra03916k}, abstractNote={The role of metal-free organic sensitizers (IMA1-4) in the improvement of photocurrent efficiency and the overall performance of the DSSCs when used as a co-sensitizer with a Ru(ii) sensitizer (IMA5).}, number={47}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, pages={27940–27953} }
 @article{abdellah_el-shafei_2020, title={Influence of carbonyl group on photocurrent density of novel fluorene based D-π-A photosensitizers: Synthesis, photophysical and photovoltaic studies}, volume={387}, ISSN={1010-6030}, url={http://dx.doi.org/10.1016/j.jphotochem.2019.112133}, DOI={10.1016/j.jphotochem.2019.112133}, abstractNote={Herein, we developed novel and promising low-cost metal free organic dyes 7a-c and 10a-c via a simple, highly efficient, and high yield through two-step methodology based on Suzuki coupling reaction. These new dyes characterized with D-π-A architecture, utilized a binary π-conjugated spacer comprised of fluorenone and thiophene or spiro fluorene and thiophene. This construction would help in studying the impact of π-spacers on the photovoltaic (PV) parameters of fabricated DSSCs. The highest photocurrent efficiency (PCE) of 3.5%, JSC (7.80 mA cm−2), VOC (0.62 V) and FF (69.11%) was achieved by photosensitizer 10b incorporating spiro fluorene π-spacers moiety compared to PCE of 2.70%, JSC (6.45 mA cm−2), VOC (0.57 V) and FF (71.50%) for dye 7b with fluorenone π-spacers at the AM1.5 G conditions and using a volatile redox electrolyte (iodide/triiodide). DFT/TD-DFT calculations were used to clarify the relation between the molecular structure, photophysical and photoelectrochemical properties utilizing GAUSSIAN 09 programming. Interestingly, DFT results showed a distribution of a frontier LUMO isosurface between the carbonyl group of fluorenone and the acceptor part in case of photosensitizers 7a-c compared to 10a-c, which shows a complete frontier LUMO shift to the acceptor part only. This confirms the effect of carbonyl group on trapping the electrons. This causes a weak electron injection into TiO2 surface, which lowered the photocurrent conversion efficiency of 7a-c dyes compared to 10a-c. The dyes structures were confirmed by UV–vis, emission spectrophotometry, FT-IR, ESI-MS and 1H-NMR.}, journal={Journal of Photochemistry and Photobiology A: Chemistry}, publisher={Elsevier BV}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, month={Jan}, pages={112133} }
 @article{abdellah_chowdhury_lee_islam_el-shafei_2020, title={Novel dopant-free hole-transporting materials for efficient perovskite solar cells}, volume={206}, ISSN={0038-092X}, url={http://dx.doi.org/10.1016/j.solener.2020.06.016}, DOI={10.1016/j.solener.2020.06.016}, abstractNote={Two novel highly conjugated small organic molecules as hole transporting materials (HTMs) coded T(EDOT-TPA)2 and DBT(QT-TPA)2 were designed and developed by utilizing facile synthetic procedures with high yields. The fabricated perovskite solar cells (PSCs) utilizing these HTMs without any dopants under 1 sun illumination (100 mW cm−2, AM 1.5G) and surface area of 1.02 cm2 achieved a short circuit current (JSC = 19.23), open circuit voltage (VOC = 1.042), fill factor (FF = 0.679) and overall power conversion efficiency (PCE = 13.61%) for DBT(QT-TPA)2. While, T(EDOT-TPA)2 exhibited (JSC = 20.25, VOC = 1.04, FF = 0.583, and PCE = 12.27%). These dopant free HTM based PSCs achieved superior PCEs compared to that of undoped Spiro-OMeTAD (PCE = 9.34%) based PSCs and a comparable photovoltaic performance to the PSCs using doped Spiro-OMeTAD (JSC = 20.37, VOC = 1.057, FF = 0.74, and PCE = 15.93) as the HTM under same fabrication conditions. Noticeably, the absence of additives is of significant importance, as DBT(QT-TPA)2 and T(EDOT-TPA)2 based PSCs still produces a Jsc up to 20.25 mA cm−2 and a comparable PCE of 13.61%, which reduces the fabrication cost of cm sized PSCs.}, journal={Solar Energy}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Chowdhury, Towhid H. and Lee, Jae-Joon and Islam, Ashraful and El-Shafei, Ahmed}, year={2020}, month={Aug}, pages={279–286} }
 @article{keremane_abdellah_naik_el-shafei_adhikari_2020, title={Simple thiophene-bridged D–π–A type chromophores for DSSCs: a comprehensive study of their sensitization and co-sensitization properties}, volume={22}, ISSN={1463-9076 1463-9084}, url={http://dx.doi.org/10.1039/d0cp02781b}, DOI={10.1039/d0cp02781b}, abstractNote={DSSCs were fabricated using new dyes T1–4 as sensitizers/co-sensitizers along with the MH-12 dye. This work highlights the optimization of various factors involved in the cell as well as a complete analysis on their structure-performance behaviour.}, number={40}, journal={Physical Chemistry Chemical Physics}, publisher={Royal Society of Chemistry (RSC)}, author={Keremane, Kavya S. and Abdellah, Islam M. and Naik, Praveen and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2020}, pages={23169–23184} }
 @article{abdellah_el-shafei_2020, title={Synthesis and characterization of novel tetra anchoring A2-D-D-D-A2 architecture sensitizers for efficient dye-sensitized solar cells}, volume={198}, ISSN={0038-092X}, url={http://dx.doi.org/10.1016/j.solener.2020.01.040}, DOI={10.1016/j.solener.2020.01.040}, abstractNote={Novel metal free organic dyes coded TET(RA)4, TET(CA)4, and TET(QA)4 were designed, synthesized, and characterized as effective sensitizers for dye sensitized solar cells (DSSCs). These new push-pull sensitizers used a strong electron donor consisting of 3,4-ethylenedioxythiophene and two triphenylamine molecules connected together to form a TPA-EDOT-TPA (TET) motif, which is directly connected to tetra anchoring groups (A) without any π-spacers to construct A2-D-D-D-A2 architecture, three different anchoring series, viz. rhodanine-3-acetic acid (RA), cyanoacetic acid (CA), and 2-methyl quinoline-6-carboxylic acid (QA) were employed to investigate the influence of anchoring moieties on the electrochemical, thermodynamic, kinetics, and photovoltaic efficiency of DSSCs. The DSSCs devices showed a maximum overall power conversion efficiency (PCE) = 5.13%, short-circuit current density (JSC) = 12.71 mA.cm−2, open circuit voltage (VOC) = 0.62 V, and fill factor (FF) = 65.36% with a maximum incident photon conversion efficiency (IPCE) = 75% for TET(QA)4. The optical and electrochemical studies showed that TET(QC)4 achieved higher electron injection free energy (ΔG°inj) into CB edge of TiO2 as well as high recombination resistance (Rrec) compared to TET(RA)4, and TET(CA)4, which explains the outstanding charge separation and superior power conversion efficiency (PCE) of TET(QC)4 possessing quinoline-6-carboxylic acid (QC) anchoring group. Molecular modeling calculations using DFT and TD-DFT showed effective charge separation, where HOMO is delocalized over the donor scaffold (TPA-EDOT-TPA), and the LUMO is delocalized over only two anchoring groups on the same side of the donor system, which provides strong HOMO-LUMO overlap as well as intimate electronic coupling with TiO2 nanoparticle surface for electron injection. Further, the calculated values of the energy gaps (E0-0) and ground/excited stated oxidation potentials were in perfect agreement with the experimental results.}, journal={Solar Energy}, publisher={Elsevier BV}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, month={Mar}, pages={25–35} }
 @article{abdellah_el-shafei_2020, title={The molecular engineering, synthesis and photovoltaic studies of a novel highly efficient Ru(ii) complex incorporating a bulky TPA ancillary ligand for DSSCs: donor versus π-spacer effects}, volume={10}, ISSN={2046-2069}, url={http://dx.doi.org/10.1039/C9RA06150A}, DOI={10.1039/c9ra06150a}, abstractNote={The IA-7 complex was applied in DSSCs.}, number={1}, journal={RSC Advances}, publisher={Royal Society of Chemistry (RSC)}, author={Abdellah, Islam M. and El-Shafei, Ahmed}, year={2020}, pages={610–619} }
 @article{abdel-shakour_el-said_abdellah_su_el-shafei_2019, title={Low-cost Schiff bases chromophores as efficient co-sensitizers for MH-13 in dye-sensitized solar cells}, volume={30}, ISSN={0957-4522 1573-482X}, url={http://dx.doi.org/10.1007/s10854-019-00806-2}, DOI={10.1007/s10854-019-00806-2}, number={5}, journal={Journal of Materials Science: Materials in Electronics}, publisher={Springer Science and Business Media LLC}, author={Abdel-Shakour, M. and El-Said, Waleed A. and Abdellah, Islam M. and Su, Rui and El-Shafei, Ahmed}, year={2019}, month={Feb}, pages={5081–5091} }
 @article{abdellah_koraiem_el-shafei_2019, title={Molecular engineering and investigation of new efficient photosensitizers/co-sensitizers based on bulky donor enriched with EDOT for DSSCs}, volume={164}, ISSN={0143-7208}, url={http://dx.doi.org/10.1016/j.dyepig.2019.01.035}, DOI={10.1016/j.dyepig.2019.01.035}, abstractNote={Herein, we report design, synthesis and photovoltaic performance of four novel metal-free heteroaromatic photosensitizers coded IA 1-4 with (D-D)2-D-A architecture carrying electron donating triphenylamine coupled with EDOT core which is directly connected to four different electron withdrawing/anchoring groups, viz. rhodamine-3-acetic acid, cyano acetic acid, 2-methyl quinoline-6-carboxylic acid and 1-phenyl-pyrazol-5-one-3-carboxylic acid without any π-spacer. The newly designed IA 1-4 were applied as sensitizers and co-sensitizers in DSSCs. Their structures were confirmed by FT-IR, 1H NMR, MS and elemental analyses. The photosensitizers were subjected to optical and electrochemical studies in order to investigate their absorption/emission behavior as well as HOMO/LUMO energies. The UV–Vis revealed that IA 1-4 exhibited at 464, 497, 531 and 412 nm,λmax respectively. Their optical band gap is in the range of 1.95–2.28 eV. From the energy level diagram of the named photosensitizer, it is clear that all the dyes have good thermodynamically favorable ground and excited state oxidation potentials for electron injection into CB edge of TiO2 as well as dye regeneration. The photovoltaic performance studies indicate that, dye IA-1 anchored with cyanoacetic acid displayed the highest IPCE (61.5%), resulting in PCE of 5.92% (JSC = 12.3 mA cm−2, VOC = 0.68 V, FF = 70.29%). Furthermore, when IA-1 was used as a co-sensitizer with MH-13, a total PCE of 8.43% (JSC = 22.8 mA cm−2, VOC = 0.66 V, FF = 54.1%) was achieved to gain more insights into the equilibrium molecular geometry (EMG), thermodynamic parameters and vertical electronic excitation, DFT studies were performed using GAUSSIAN 09 software to calculate the EMG of each photosensitizer, its and electron cloud delocalization of HOMO/LUMO levels and vertical electronic excitation. Results from FMO revealed that dyes IA 1-4 showed effective charge separation, which translated into greater ICT behavior with IA-1 being the highest in photovoltaic performance.}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Koraiem, Ahmed I. and El-Shafei, Ahmed}, year={2019}, month={May}, pages={244–256} }
 @article{kesavan_abdellah_singh_el-shafei_adhikari_2019, title={Simple diphenylamine based D–π–A type sensitizers/co-sensitizers for DSSCs: a comprehensive study on the impact of anchoring groups}, volume={21}, ISSN={1463-9076 1463-9084}, url={http://dx.doi.org/10.1039/C9CP01032G}, DOI={10.1039/C9CP01032G}, abstractNote={Three new diphenylamine based metal-free dyes were designed and developed as efficient sensitizers as well as co-sensitizers along with N3 in DSSCs. Their detailed photophysical, electrochemical, theoretical and photovoltaic properties have been explored.}, number={20}, journal={Physical Chemistry Chemical Physics}, publisher={Royal Society of Chemistry (RSC)}, author={Kesavan, Rajalakshmi and Abdellah, Islam M. and Singh, Surya Prakash and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2019}, pages={10603–10613} }
 @article{abdellah_koraiem_el-shafei_2019, title={Structure-property relationship of novel monosubstituted Ru (II) complexes for high photocurrent and high efficiency DSSCs: Influence of donor versus acceptor ancillary ligand on DSSCs performance}, volume={177}, ISSN={0038-092X}, url={http://dx.doi.org/10.1016/j.solener.2018.11.047}, DOI={10.1016/j.solener.2018.11.047}, abstractNote={Two novel high molar extinction coefficient monosubstituted-bipy Ru (II) complexes, IA-5 and IA-6, based on D-D-π and π-A-π-A ancillary ligands were synthesized with the aid of Knoevenagel reaction, to study the influence of the electron donor and electron acceptor ancillary ligand and number of anchoring group (COOH) on the light harvesting efficiency (LHE), ground and excited state oxidation potentials, incident-photon-to-current conversion efficiency (IPCE), short-circuit photocurrent density (J), and total solar-to-electric conversion efficiency (%η) for DSSCs, and their device performances were studied and showed a maximum of PCE of 7.81% (JSC = 17.61 mA cm−2, VOC = 0.69 V and FF = 64.05%) for dye IA-6 compared to PCE of 7.74% (JSC = 15.83 mA cm−2, VOC = 0.74 V and FF = 65.37%) for N719 dye. The photophysical and photoelectrochemical properties discussed herein addressed the significant impact of the electron donor and electron acceptor ancillary ligand and the number of anchoring groups on JSC and %η in DSSCs. The molecular structures of IA-5 and IA-6 were characterized using UV–Vis, emission spectrophotometry, FT-IR, ESI-MS, and 1H NMR. To probe the interrelationship between the chemical structure, photophysical and photoelectrochemical properties, molecular modeling studies, implemented in Gaussian, were employed. DFT/TD-DFT calculations were used to calculate the thermodynamics and electronic properties of IA-5 and IA-6 including HOMO and LUMO isosurfaces, lowest singlet-singlet electronic transitions (E0-0), ground and excited states oxidation potentials, GSOP and ESOP, which were in excellent agreement with the experimental results. Surprisingly, the insertion of the strong electron acceptor benzodithiazole in the ancillary ligand of IA-5 showed that the frontier LUMO shifted by 100% from 2,2′-bipyridyl-4,4′-dicarboxlic acid to the ancillary ligand containing benzodithiazole with electron injection accomplished from the anchoring group tethered to benzodithiazole. This new finding of relocating the LUMO from bipy-dicarboxylic acid to the other ancillary ligand would open the door for the molecular engineering of better light harvesting and more efficient Ru (II) complexes for DSSCs.}, journal={Solar Energy}, publisher={Elsevier BV}, author={Abdellah, Islam M. and Koraiem, Ahmed I. and El-Shafei, Ahmed}, year={2019}, month={Jan}, pages={642–651} }
 @article{koraiem_abdellah_el-shafei_abdel-latif_abd el-aal_2019, title={Synthesis, optical characterization, and TD-DFT studies of novel mero/bis-mero cyanine dyes based on N-Bridgehead heterocycles}, volume={97}, ISSN={0008-4042 1480-3291}, url={http://dx.doi.org/10.1139/cjc-2018-0325}, DOI={10.1139/cjc-2018-0325}, abstractNote={ Novel mero/bis-mero cyanine dyes based on N-Bridgehead imidazo[1,2-g]quinolino[2,1-a][2,6]naphthyridine have been synthesized and characterized to evaluate intramolecular charge transfer (ICT) effect on the energy gap (E0-0). The UV–vis and emission spectral studies revealed that dyes are absorbed in the region of λmax 485–577 nm and emitted at 567–673 nm. Their solvatochromic behavior in solvents of various polarities, CCl4, C6H6, H2O, CHCl3, acetone, and DMF, was studied to emphasize the effect of solvent polarity on the absorption maxima, molar extinction coefficients of the dyes, and excitation energy of the dyes. Their electron cloud delocalization in HOMO/LUMO levels were studied by DFT using Gaussian 09 software. Time-dependent density functional theory (TD-DFT) was applied to theoretically explore the first excitation energy (E0-0) of these dyes, which was in good agreement with experimental results. }, number={3}, journal={Canadian Journal of Chemistry}, publisher={Canadian Science Publishing}, author={Koraiem, Ahmed I. and Abdellah, Islam M. and El-Shafei, Ahmed and Abdel-Latif, Fathy F. and Abd El-Aal, Reda M.}, year={2019}, month={Mar}, pages={219–226} }
 @article{naik_abdellah_abdel‐shakour_acharaya_pilicode_el‐shafei_adhikari_2018, title={An Efficient Aniline‐Based Co‐Sensitizer for High Performance N3‐Sensitized Solar Cells}, volume={3}, ISSN={2365-6549 2365-6549}, url={http://dx.doi.org/10.1002/slct.201802232}, DOI={10.1002/slct.201802232}, abstractNote={Abstract}, number={43}, journal={ChemistrySelect}, publisher={Wiley}, author={Naik, Praveen and Abdellah, Islam M. and Abdel‐Shakour, M. and Acharaya, Madhukara and Pilicode, Naveenchandra and El‐Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Nov}, pages={12297–12302} }
 @article{naik_abdellah_abdel-shakour_su_keremane_el-shafei_adhikari_2018, title={Improvement in performance of N3 sensitized DSSCs with structurally simple aniline based organic co-sensitizers}, volume={174}, ISSN={["0038-092X"]}, url={http://dx.doi.org/10.1016/j.solener.2018.09.071}, DOI={10.1016/j.solener.2018.09.071}, abstractNote={In this work, we report comprehensive photovoltaic investigation of four structurally simple D-A configured organic dyes, A1-4 as active co-sensitizers in DSSCs sensitized with well-known Ru (II) based N3 dye. These effective co-sensitizers (A1-4) comprise N,N-dimethylaniline ring as donor scaffold linked with electron withdrawing functionalities, viz. barbituric acid (A1), N,N-dimethyl barbituric acid (A2), thiobarbituric acid (A3), and N,N-diethyl thiobarbituric acid (A4) as acceptor/anchoring units. In the present study, for the first time we have demonstrated the profound role of various simple organic molecules carrying different heterocyclic anchoring units on the photovoltaic parameters of the N3 sensitized devices. Also, the effect of concentration of sensitizer/co-sensitizers on the device performance characteristics has been investigated in depth. From the results, it is evident that, the device fabricated using co-sensitizer A2 carrying N,N-dimethyl barbituric acid along with sensitizer N3 in all concentrations outperformed when compared to N3 alone or other co-sensitizers. Interestingly, the best photovoltaic performance was obtained for the co-sensitized device fabricated using 0.3 mM co-sensitizer A2 along with 0.2 mM of N3 sensitizer. It displayed PCE of 7.02% with JSC of 15.27 mA·cm−2, VOC of 0.671 V and FF of 68.47%. Thus, the observed results have thrown new light upon the device optimization to yield DSSCs with improved performance by the selection of matchable co-sensitizers at appropriate concentrations.}, journal={SOLAR ENERGY}, author={Naik, Praveen and Abdellah, Islam M. and Abdel-Shakour, M. and Su, Rui and Keremane, Kavya S. and El-Shafei, Ahmed and Adhikari, Airody Vasudeva}, year={2018}, month={Nov}, pages={999–1007} }
 @article{microwave assisted synthesis and solvato (media)-chromic behaviour of some new series photosensitizing dyes_2018, url={http://www.joac.info/}, journal={Journal of Applicable Chemistry}, year={2018} }
 @article{novel cyanine dyes based on n-bridgehead heterobicyclic: synthesis, solvatochromism and physicochemical studies_2018, journal={Organic Chemistry: An Indian Journal}, year={2018}, month={Jun} }
 @article{koraiem_abdellah_el-shafei_2018, title={Novel Zero/ monomethine cyanine dyes based on N-Bridgeheadpyrazolo[4', 3’:3,4]pyrido[1,2-c]pyrido[1,2-a]pyrimidine: Synthesis and photo-physical properties}, volume={5}, ISSN={2350-0328}, number={6}, journal={International Journal of Advanced Research Science, Engineering and  Technology}, author={Koraiem, A.I. and Abdellah, I.M. and El-Shafei, A.}, year={2018}, pages={6009–6017} }
 @article{koraiem_abdellah_el-shafei_2018, title={Novel Zero/monomethine cyanine dyes based on N-Bridgeheadpyrazolo [4', 3’: 3, 4] pyrido [1, 2-c] pyrido [1, 2-a] pyrimidine: Synthesis and photophysical properties}, url={http://www.ijarset.com/}, journal={International Journal of Advanced Research in Science, Engineering and Technology}, author={Koraiem, Ahmed I and Abdellah, Islam M and El-Shafei, Ahmed M}, year={2018}, month={Jun} }
 @article{synthesis and photophysical characterization of highly stable cyanine dyes based on pyrazolo[5,4-b]pyrido[2,1-c]pyrimidine and pyrazolo [5,4-b]pyrido[2,1-d][1,3,4] triazepine_2018, url={http://www.joac.info/}, journal={Journal of Applicable Chemistry}, year={2018} }
 @article{koraiem_abdellah_el-shafei_2018, title={Synthesis and Photophysical Properties of Novel Highly Stable Zero/Bis-Zero Methine Cyanine Dyes Based on N-Bridgehead Heterocycles}, volume={08}, ISSN={2161-4687 2161-4695}, url={http://dx.doi.org/10.4236/ijoc.2018.83021}, DOI={10.4236/ijoc.2018.83021}, abstractNote={Cyanine dyes of zero/bis-zero methine incorporating imid-azo(1,2-a)Pyridine (quinoline) or pyrazino(1,2-a)pyridine (quinoline) with stable C-N bond were synthesized using keto-oxime methylene C-link heterocyclic quaternary salts [1-phenyl-3-methyl-pyrazolino-4-keto-oxime-α-methylene-bis-pyridin-(quinoin)-1(4)-di-ium-iodide(ethiodide) salts and 1-phenyl-3-methyl-pyrazolino- 4-ketooxime-α-methylene-N-2-methyl-bis pyridin (quinoin)-1(4)-di-ium-iodide(ethiodide) salts]. Such heterocyclic precursors and related dyes were identified by elemental and spectral analyses. The absorption spectra properties of such dyes were investigated in 95% Ethanol to attempt and throw some light on the influence of such new heterocyclic nuclei and to compare or evaluate spectral behaviors. The absorption spectra of dyes in different pure solvents were examined in the visible region showing solvatochromism and the colour changes of dyes with solvents having different polarities. This permits a selection of the optimal solvent (fractional solvent) when such dyes are applied as photosensitizers. The spectral behavior of some selected newly synthesized cyanine dyes is observed in mixed solvents of different polarities and progressively increasing quantities of one solvent over the other were studied and showed an increase in the absorbance of CT band with increasing proportion of that solvent. Evidence for hydrogen bond formation between the solute molecules and solvent molecules allows measurement of certain energies such as hydrogen bonding, orientation, and free energies.}, number={03}, journal={International Journal of Organic Chemistry}, publisher={Scientific Research Publishing, Inc.}, author={Koraiem, Ahmed I. and Abdellah, Islam M. and El-Shafei, Ahmed M.}, year={2018}, pages={282–297} }
 @article{koraiem_el-shafei_abdellah_2018, title={Synthesis and physicochemical properties of novel zero methine cyanine dyes based on N-bridgehead indolizine (benzoindolizine) heterocycles}, volume={5}, url={http://www.ijarset.com}, number={5}, journal={International Journal of Advanced Research in Science, Engineering and Technology}, author={Koraiem, Ahmed I and El-Shafei, Ahmed M and Abdellah, Islam M}, year={2018}, month={May} }
 @article{koraiem_el-shafei_abdellah_abdel-latif_abd el-aal_2018, title={Theoretical and experimental spectroscopic investigation of new polymethine donor-π-acceptor cyanine dyes: Synthesis, photophysical, and TDDFT studies}, volume={1173}, ISSN={0022-2860}, url={http://dx.doi.org/10.1016/j.molstruc.2018.07.021}, DOI={10.1016/j.molstruc.2018.07.021}, abstractNote={New series of polymethine cyanine dyes with different length of π-chain have been synthesized and characterized. These new dyes are based on D-π-A architecture with long π-electron systems. The UV–vis/emission spectral studies showed that the dyes are absorbed in the region of λmax (485–570) nm and emitted at (540–600) nm. This makes these dyes favorable for the detection of biological and chemical analytes. Their electron cloud delocalization in HOMO/LUMO levels were studied by DFT using Gaussian 09 software. DFT results reveal that the dyes showed effective charge separation in its molecular orbitals levels, which reflected in its ICT behavior. Time-dependent density functional theory (TD-DFT) were applied to theoretically explored the first excitation energy (E0-0) of these dyes which in high compatibility with experimental results with an accuracy of 0.1–0.3 eV. This approach has been successfully applied to describe the great effect of π-conjugation length and substituents of chromophore on the variations of maximum absorption and excitation energy of the dyes.}, journal={Journal of Molecular Structure}, publisher={Elsevier BV}, author={Koraiem, Ahmed I. and El-Shafei, Ahmed and Abdellah, Islam M. and Abdel-Latif, Fathy F. and Abd El-Aal, Reda M.}, year={2018}, month={Dec}, pages={406–416} }