Flavonoid from Hedera helix fruits: A promising new natural sensitizer for DSSCs

Owing to their lower cost, simplicity of manufacture, environmental friendliness, and accessibility of raw materials, natural dyes emerge as the most viable substitute for dye-sensitized solar cells (DSSCs). However, the photovoltaic performance of DSSCs based on natural dyes stays behind that of their metal-based counterparts. This can be partially overcome when appropriate chemical additives are present in the redox electrolyte employed in DSSCs based on natural dyes. To determine the ideal additives for DSSCs based on natural dye extracted from Hedera helix fruits, including flavonoid pigments, we thoroughly compare the actions of 1-butyl-3-methylimidazolium iodide, guanidinium thiocyanate, and tert-butylpyridine additives in ionic liquid-based redox electrolytes. These additives suppress undesirable charge recombination and parasitic resistance effects, achieving a more significant enhancement of open-circuit voltage (Voc) of 130 mV and fill factor (FF) of 30 % compared to their counterparts. Utilizing prepared electrolyte solutions in DSSCs also presents an outstanding increase in the efficiency of the devices, from 0.75 % to 1.17 % (∼56 % improvement), which outperforms other natural dye sources containing flavonoid pigments as well. The experimental findings provided in this study demonstrate that the development of electrolytes tailored for natural dyes can lead to greater power conversion efficiency. © 2023 Elsevier B.V

MOLEKÜLER MEKANİK VE YOĞUNLUK FONKSİYONELLERİ TEORİSİ METODLARIYLA SİYANOASETİK ASİT MOLEKÜLÜNÜN MOLEKÜL VE RADİKAL YAPILARININ BELİRLENMESİ

MOLEKÜLER MEKANİK VE YOĞUNLUK FONKSİYONELLERİ TEORİSİ METODLARIYLA SİYANOASETİK ASİT MOLEKÜLÜNÜN MOLEKÜL VE RADİKAL YAPILARININ BELİRLENMESİÖzetSiyanoasetik asit molekülünün potansiyel enerji yüzeyleri moleküler mekanik metotlarla taranmış ve elde edilen konformasyonların geometrileri B3LYP metodu ve 6-311++G(d,p) baz setleriyle optimize edilmiştir. Molekülün beş farklı konformasyonu tespit edilmiştir. En kararlı konformasyonun yapısı, molekül yapısı olarak atanmıştır. Molekül yapısıyla ilgili daha önce yapılmış deneysel bir çalışma olmadığından molekülün geometri parametreleri detaylı bir şekilde ilk defa bu çalışmada verilmiştir. Literatürde yer alan teorik çalışmalarda elde edilmiş olan konformasyonlardan daha fazla konformasyon yapısı bu çalışmada tespit edilmiştir. En kararlı yapı kullanılarak ışınlama sonucunda oluşabilecek muhtemel radikaller modellenmiştir. Modellenen bu radikallerin konformasyon analizleri yapılıp en kararlı radikallerin Elektron Paramagnetik Rezonans parametreleri B3LYP metodu ve TZVP baz setleri kullanılarak hesaplanmıştır. Hesaplanan parametreler deneysel değerlerle karşılaştırılıp radikal yapısı belirlenmiştir. Tespit edilen radikalin detaylı geometri parametreleri ilk defa bu çalışmada verilmiştir.Anahtar Kelimeler: Siyanoasetik asit, Konformasyon Analizi, Molekül Yapısı, Radikal Yapısı.DETERMINATION OF MOLECULE AND RADICAL STRUCTURES OF CYANOACETIC ACID USING MOLECULAR MECHANIC AND DENSITY FUNCTIONAL THEORY METHODSAbstractPotential energy surfaces of cyanoacetic acid molecule was scanned by molecular mechanic methods and geometries of obtained conformers were optimized by B3LYP method and 6-311++G(d,p)  basis sets. Five different conformers of the molecule were determined. The more structure of conformers than other theoretical studies performed before in the literature were determined. Using the most stable one, possible radicals which can be obtained from UV-irradiation were modeled. After the conformational analysis of these model radicals were performed, EPR parameters of the most stable ones were calculated by B3LYP method and TZVP basis sets. Comparing the calculated values with experimental counterparts, radical structure of the molecule was determined. Detailed geometry parameters of the obtained radical and molecule were given for the first time in this study.Keywords: Cyanoacetic acid, Conformational Analysis, Molecular Structure, Radical Structure

THEORETICAL AND EXPERIMENTAL INVESTIGATION OF 1,3-BIS(4-PIPERIDYL)PROPANE MOLECULE AND THE METAL (II) HALIDE COMPLEXES AND FREE OF 1,3-BIS(4-PYRIDYL)PROPANE MOLECULE

Bu çahsmada, 1,3 bis(4-piperidil)propan, 1,3 bis(4-piridil)propan molekiillerinin titreşim frekanslan ve geometrik parametreleri hesaplandı. Hesaplamalar Gaussian 03W ve GaussView programlan kullanılarak HF ve DFT/ B3LYP, BLYP fonksiyonelleri, 6-311G(d,p) ve 6-31G(d) temel setler kullanılarak yapıldı. Hesaplanan titreşim frekanslan ve geometrik parametreler deneysel değerler ile karşılaştinldı. M(l,3-bis(4-piridil)propan)X2 (M: Hg ve Zn, X:C1, Br ve I) ve Zn(4-asetilpiridin)2X2 (X:C1, Br ve I) bileşikleri deneysel olarak elde edildi. Elde edilen bileşiklerin infrared spektrumlan 400-4000 cm\"1 bölgesinde ve Raman spektrumlan 5-3500 cm\"1 bölgesinde kaydedildi. Hazırlanan bu bileşiklerin C, N ve H elemental analiz sonuçlan verildi. Serbest ligand molekülleri ile bileşik yapıdaki ligand molekülünün titreşim frekanslan karşılaştinldı. Bileşiklerin titreşim frekans değerlerinde serbest ligand frekanslarma göre kaymalar belirlendi. Bu kaymalann metale bagh olarak değiştiği ve ligandın iç titresimleri ile M-N bagi titreşimleri arasındaki mekanik çiftlenimden kaynaklandigi anlaşıldı. 2 M(l,3-bis(4-piridil)propan)X2 (M: Hg ve Zn, X:C1, Br ve I) ve Zn(4-asetilpiridin)2X2 (X:C1, Br ve I) bileşiklerinin titreşim frekanslan ve geometrik parametreleri Gaussian 03W ve Gaussview 3.1 paket programlan yardımıyla hesaplandı. Hesaplamalar DFT/B3LYP fonksiyonel, LANL2DZ ve SDD temel setler kullanılarak yapıldı. Teorik olarak hesaplanan titreşim frekanslan ve geometrik parametreler X-isınlan verileri ile karşılaştinldı.In this study, the geometric parameters and the vibrational frequencies of 1,3 bis(4-piperidyl)propane, 1,3 bis(4-pyridyl)propane molecules are calculated by means of HF and DFT/ B3LYP, BLYP functionals and 6-311G(d,p) and 6-31 G(d) basis sets of Gaussian 03W and GaussView programs. Calculated vibrational frequencies and geometric parameters are compared with the experimental values of free ligands. M(1,3 -Bis(4-Pyridyl)Propane)X2 (M: Hg and Zn, X:Cl, Br and I) and Zn(4-Acetylpyridine)2X2 (X:Cl, Br and I) metal halogen compounds have been prepared. The infrared spectra of all compounds have been recorded between 400-4000 cm-1 region. Raman spectra of all compounds have been recorded between 5-3500 cm-1 region. The results of C, N and H analysis of all the compounds are given. The infrared spectra of the complexes and free ligands are compared. There are some shifts in the IR spectra of metal complexes due to the complex formation. These shifts are metal dependent and explained by the coupling of the internal modes of ligand molecules with the M-N vibration. The geometric parameters and vibrational frequencies of M(1,3-bis(4-pyridyl)propane)X2 (M: Hg ve Zn, X:Cl, Br ve I) ve Zn(4-acetylpyridine)2X2 (X:Cl, Br ve I) through DFT/ B3LYP functional and LANL2DZ and SDD basis sets of Gaussian 03W and Gaussview 3.1 package programs. Calculated vibrational frequencies and geometric parameters are compared with the experimental values of complexes

Vibrational analysis of flavone

In this study, the experimental and theoretical study on the structures and vibrations of flavone are presented. FT-IR and FT-Raman spectra of the molecule have been recorded in the 400-4000 cm-1 region and the 5-3500 cm-1 region, respectively. The molecular geometry and vibrational frequencies of flavone in the ground state have been calculated by using Density Functional method (B3LYP) in conjunction with 6-311++G(d,p) and 6-31++G(d) as basis sets.In this study, the experimental and theoretical study on the structures and vibrations of flavone are presented. FT-IR and FT-Raman spectra of the molecule have been recorded in the 400-4000 cm-1 region and the 5-3500 cm-1 region, respectively. The molecular geometry and vibrational frequencies of flavone in the ground state have been calculated by using Density Functional method (B3LYP) in conjunction with 6-311++G(d,p) and 6-31++G(d) as basis sets

Evolution of the electronic structure and properties of charged titanium doped aluminum nanoclusters

A systematic study of the titanium doped aluminum clusters with various spin multiplicities have been performed by using Density Functional Theory calculations at the B3LYP/6-311++G(d,p) level. The HOMO-LUMO energy gap, ionization potential (IP), electron affinity (EA), Adiabatic Electron Affinity (AEA), Vertical Electron Affinity (VDE) and vertical detachment energy (VDE) are also computed for the most stable isomer of each cluster

Tribological Behaviors of Natural Fiber Reinforced Nanofilled Polyurea Matrix Composites at High Temperatures

The properties of natural fibers such as poor ultraviolet (UV) resistance and hydrophilicity that reduce the durability of composites limit their usage as reinforcements in polymer matrix composites. To compensate this, new types of composites are proposed in the present study. The tribological behaviors of multiphase composites with polyaspartic polyurea matrix produced by vacuum assisted resin transfer molding (VARTM) technique with jute reinforced, filled by graphene nanoplatelets (GNPs) and titanium dioxide (TiO2) nano-fillers at high temperatures are investigated. The wear tests were performed under 10, 20, and 30 N loads, at 60% humidity and temperatures of 100°C, 125°C, and 150°C using a heat moduled pin-on-disc tribotester with an AISI 4140 counter-surface disc having an average surface roughness value of 1.033 µm. The tests were carried out under dry friction conditions along 6000 m sliding distance at a sliding speed of 2 m/s. The results show that the wear damage types changed according to the nano-filler type. Wear loss and specific wear rate increased with increasing temperature and load in almost all types of composites. Using nano-filler caused irregularities in the change of the friction coefficient