Tóm tắt: Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.

Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.Nghiên cứu cấu trúc và tính chất một số hệ vòng ngưng tụ chứa lưu huỳnh và silic ứng dụng trong chế tạo vật liệu quang điện.MINISTRY OF EDUCATION AND TRAINING HANOI UNIVERSITY OF EDUCATION TRAN NGOC DUNG Study on the structure and properties of some sulfur and silicon containing fused rings applied in the fabrication of ph.

MINISTRY OF EDUCATION AND TRAINING

HANOI UNIVERSITY OF EDUCATION

TRAN NGOC DUNG

Study on the structure and properties of some and silicon-containing fused rings applied in the fabrication of photovoltaic materials

sulfur-Specialization: Theoretical and Physical Chemistry

University of Education

Scientific Instructors:

1 Assoc Prof Dr Nguyen Thi Minh Hue

2 Assoc Prof Dr Nguyen Hien

Review 1: Prof Tran Thi Nhu Mai

Hanoi University of Sciences – Vietnam NationalUniversity, Hanoi

Review 2: Prof Pham Cam Nam

University of Science and Technology – TheUniversity of Danang

Review 3: Prof Nguyen Thanh Tung

Institute of Materials science – Vietnam Accademy

of Science and Technology

The thesis will be presented to the Board of thesis review at Hanoi University of Education on h day month year

The thesis can be found at: National Library, Hanoi or the library of

Hanoi National University of Education

LIST OF WORKS PUBLISHED BY AUTHOR

1) Nguyen Van Trang, Tran Ngoc Dung, Tran Thi Thoa, Dinh Thi MaiThanh, and Nguyen Thi Minh Hue "Stability and Semi‐ConductiveProperty of Some Derivatives of Mono‐and Di‐Silole: A Theoretical Study."Vietnam Journal of Chemistry 57, no 4 (2019): 507-13

2) Tran Ngoc Dung, Nguyen Van Trang, Dinh Thi Mai Thanh, Nguyen ThiVan Khanh, Hien Nguyen, and Hue Minh Thi Nguyen "A FacileRegioselectively Synthesis of 2-Alkenylbenzo [1, 2-B: 4, 5-B’] Dithiophene

by Pd/Cu/Ag-Catalyzed Ch Functionalization." ChemistrySelect 5, no 19(2020): 5581-86

3) Tran Ngoc Dung, Nguyen Van Trang, Tran Thi Thoa, Phan Thi Thuy,Dinh Thi Mai Thanh, and Nguyen Thi Minh Hue "Theoretical Study ofStructures and Properties of Some Silole Compounds." Vietnam Journal ofChemistry 58, no 2 (2020): 212-20

4) Nguyen Van Trang, Tran Ngoc Dung, Ngo Tuan Cuong, Le Thi HongHai, Daniel Escudero, Minh Tho Nguyen, and Hue Minh Thi Nguyen

"Theoretical Study of a Class of Organic D-Π-a Dyes for Polymer SolarCells: Influence of Various Π-Spacers." Crystals 10, no 3 (2020): 163.5) Nguyen Van Trang, Tran Ngoc Dung, Long Van Duong, My PhuongPham-Ho, Hue Minh Thi Nguyen, and Minh Tho Nguyen "Structural,Electronic, and Optical Properties of Some New DithienosiloleDerivatives." Structural Chemistry 31, no 6 (2020): 2215-25

6) Nguyen Van Trang, Nguyen Minh Tam, Tran Ngoc Dung, and Minh ThoNguyen "A Theoretical Design of Bipolar Host Materials for BluePhosphorescent Oled." Journal of Molecular Graphics and Modelling 105(2021): 107845

7) Hue Minh Thi Nguyen, Tran Ngoc Dung, Nguyen Van Trang, Ngo TuanCuong, Nguyen Van Minh, Hien Nguyen, and Minh Tho Nguyen "Design

of Fused Bithiophene Systems Containing Silole and Five-MemberedHeterocycles for Optoelectronic Materials." Chemical Physics Letters 784(2021): 139093

1 The reason for choosing topic

Organic photovoltaic materials have many advantages over traditionalinorganic materials such as low cost, easy fabrication with large surface areaand no high temperature required in the production process Organicphotovoltaic materials are commonly used in the manufacture of organiclight-emitting diodes, organic solar cells, field-effect transistors and sensors.Sulfur-containing heterocyclic compounds are one of the important linksconstituting photovoltaic organic compounds Among them, thiophene ring isthe most popular material thanks to its photovoltaic properties and goodcharge transfer ability The thiophene ring has a pentagonal aromatic ringstructure, consisting of a sulfur atom bonded to a butadiene compound Thesulfur atom has two unbonded electron pairs, one of which is involved in theformation of aromaticity for the ring The sulfur atom is highly polar becausethe outermost electrons orbit the large 3s and 3p orbitals, facilitating electrondonation and weak bond formation Furthermore, the sulfur atom canincrease its oxidation number thanks to the contribution of the 3d orbital.Thanks to the high oxidation numbers, the sulfur atom in the thiophene ringcan form functional groups containing oxygen atoms and exhibit specialphotoelectric properties

Since 2005, a number of silicon-containing heterocyclic derivatives havebeen noticed due to their special electron properties In which, the siole ring

is focused on research by scientists Silole has a similar structure tothiophene, the sulfur atom in thiophene is replaced by a silicon atom Silicon-containing heterocycles generally have lower LUMO energies than otherheteroatoms, thus leading to a lower HOMO-LUMO gap Therefore, silicon-containing heterocyclic compounds are expected to give good luminescenceand charge transfer performance Therefore, this thesis proposes toinvestigate a number of condensate systems containing sulfur and silicon tostudy and compare their photoelectric properties

Calculation software and quantum chemistry methods become aneffective tool in studying and investigating molecular structures, chemicalreaction mechanisms under different conditions Besides, if using moderncalculation methods and high basis functions, the results will be very close tothe experiment Within the framework of this thesis, quantum chemicalcalculations will be used to investigate the substance systems, therebyproviding orientation for the experimental synthesis process later At thesame time, quantum chemical calculations also help to support and explainexperiments as well as investigate properties that are difficult to performunder experimental conditions in Vietnam.

2 Research purpose and tasks

a) Research purpose: Simulating and predicting the relationship betweenthe structure and properties of the condensed cyclic system containingthiophene and siole heterocycles by quantum chemical calculations Based onthe calculated results, they will guide the experimental synthesis of optimizedstructures with superior properties that can be applied to manufacturingphotovoltaic devices

+ Determining and evaluating the semiconductor and luminescenceproperties of condensed ring systems containing thiophene and siloleheterocycles

+ The results obtained from quantum chemical calculations will guide theselection of substituents and conjugate chain structures to create moleculeswith desired properties

5

+ Proposing optimal structures with the most preeminent properties toguide experimental synthesis

3 Scope and object of the study

a) Object: Fused heterocyclic organic compounds containing silole,thiophene and derivative functional groups which have potential applications

in organic photovoltaic devices

b) Scope of research: Theoretical research of the structure andphotoelectric properties of compounds based on the density functionalmethod From the results of theoretical research, select and propose potentialcompounds for experimental synthesis

4 Scientific and practical significance of the thesis

- Apply quantum chemical calculations to clarify the relationship betweenthe molecular structure of sulfur- and silicon-containing condensates and thephotoelectric properties of the material

- Research and design some compounds with better photoelectricproperties than existing ones theoretically, thereby making suggestions forthe synthesis of photovoltaic organic materials in the future

- Using quantum chemical calculations to confirm the products obtainedfrom organic synthesis

5 New points of the thesis

- Systematic comparison of bithiophene compounds with differentsubstituents such as thiophene, siole, pyrole,

- Replacing the thiophene bridge in the PBDTS-TZNT compound with

other condensed heterocycles has improved the light transmission and

absorption of the compound, typically the DTS heterocycle.

- Successfully replaced the AgOCOCF3 reactant with Ag2O in the

alkenylation of BDT derivatives, thereby reducing the cost of conducting the

reaction while the reaction efficiency remained unchanged Applycomputational chemistry to demonstrate the product of the BDT alkenylationreaction

6 The layout of the thesis

Introduction: Introducing the reason for choosing the topic, the purpose

and tasks of the research, the object and scope of the research, the scientificand practical significance of the thesis and the new points of the thesis

Chapter 1: Introduce the theoretical basis including the theoretical basis

of photovoltaic materials, the theoretical basis of quantum chemistry on theDFT density functional method Research substance system includesthiophene and silole system

Chapter 2: Research methods Research methods include experimental

research methods and theoretical research methods

Chapter 3: Research results and discussion, including theoretical research

results and experimental results of organic synthesis

Conclusion: Summarize the outstanding results of the thesis.

The thesis consists of 135 pages, 24 tables of data, 44 figures, 190references Introduction: 4 pages; Chapter 1: 34 pages; Chapter 2: 11 pages;Chapter 3: 70 pages Conclusion and recommendations: 2 pages; List ofpublished works: 1 page; References: 13 pages

Chapter 1 THEORY BASIS

1.1. Organic photovoltaic material

Organic photovoltaic materials are solid substances that exist in the form

of molecular crystals or amorphous thin films made up of molecules orpolymers containing π bonds, which are mainly composed of carbon andhydrogen In addition, there may be heterogeneous elements such as oxygen,sulfur, nitrogen Organic photovoltaic materials have attracted the attention

of scientists thanks to their superior physicochemical properties: i) Lowproduction cost, easy to produce on large scale; ii) capable of making thin,light and flexible devices, iii) easy to customize materials according to theintended use Despite such advantages, these compounds still have certainlimitations, especially in terms of strength and electrical conductivity

1.2.Theoretical foundations of quantum chemistry

7

The Schrödinger equation can be solved exactly for electron and nucleus system However, for systems with two or more electrons, exactsolution is not possible due to the interaction between electrons and theincrease of variables in the wave function The density functional method isproposed to optimize the solution of the Schrödinger equation, especially inthe calculation of large and multi-electron systems Unlike wave function-based methods, this method is based on electron density In this way, thenumber of variables in the Schrödinger equation is reduced to only 3, therebysaving computation time.

one-1.3.Theoretical basis of synthetic heterocyclic derivation

Condensed heterocyclic compounds have attracted the attention ofscientists due to their diverse physical and chemical properties for a longtime The basis for creating this diversity lies in the diversity of substituents.The reactions to add substituents to the existing organic framework aremostly coupling reactions, i.e new carbon-carbon bond formation reactionssuch as Heck, Suzuki, Sonogoshira, Negishi, Kumada, Stille, Tsuji-Trostreactions

Chapter 2 OVERVIEW OF RESEARCH SUBSTANCE SYSTEM

AND RESEARCH METHODS 2.1 Overview of the studied compounds

The thiophene molecule has a pentagonal aromatic ring structure,consisting of a sulfur atom bonded to a butadiene compound Among thepotential compounds for organic photovoltaic materials, thiophene-basedcompounds represent an irreplaceable role due to their superior photoelectricproperties Modulation of the HOMO-LUMO energy of organic photovoltaicmaterials can be accomplished using thiophene rings or stiff structures withbroad π conjugates of thiophene Silole is a heterocyclic compoundcontaining one atom of valence IV silicon, directly bonded to two hydrogenatoms and a butadiene compound The siole molecule has a lower LUMOenergy level than other pentacyclic aromatic compounds such as pyrole, furan

or thiophene The low LUMO energy level is thought to be caused by thestrong interaction between the π* orbital of the butadiene component and theantibonding σ* ortibal of the bond between the silicon atom and thesubstituent at the silicon atom

2.2 Research methodology overview

2.2.1 Theoretical research method

All structures are built based on Gaussview 6 software The initialstructural parameters will be optimized by Gaussian 09 software at the Centerfor Computational Science, Hanoi National University of Education

After conducting structure optimization with the functional B3LYP, thestructures will be calculated the frequency of oscillations at the appropriateset of basis functions to confirm that the obtained structure is the structure inthe ground state

9

From the optimized structure, the properties of charge transmission, Vis spectrum, will be calculated on Gaussian 09 software, then processed results based on Gaussview 6 and Chemcraft software.

UV-2.2.2 Experimental research methods

Alkenization of BDT

Place the DMSO solvent into the flask, then add one equivalent of BDT,

three corresponding alkene equivalents, 10 mol% Pd(OAc)2, 20 mol%Cu(OAc)2 and finally one Ag2O equivalent Then place the magnet bar inthe reaction vessel, install the condenser and heat on a magnetic stirrer heated

at 100-110 °C for four hours

During reaction optimization, the reaction mixture will be checked every

30 min by thin plate chromatography The solvent used is a mixture ofsuitable proportions of n-hexane and ethyl acetate The thin plate will beilluminated with ultraviolet light with two wavelengths 265 nm and 354 nm

to monitor the progress of the reaction

After the reaction was completed, the product mixture was diluted withethyl acetate, extracted with distilled water to remove the catalyst and by-products The solution containing the main product was adsorbed onto thesilica gel for purification by column chromatography

The column used was 20 × 50 mm with silica gel of 40-230 mesh Thesolvent used was a mixture of n-hexane and ethyl acetate

The product after being purified will be measured by 1H NMR, 13C NMR,HSQC, HBMC and NOESY spectra to confirm the structure

Chapter 3: RESEARCH RESULTS AND DISCUSSION

3.1 Research on applied dipole compounds as host materials in

second-generation OLED

Parent compound (M 0 )

Bphen

CBP

Figure 3.1: The structure of the compounds is studied based on the groups

of Cz, DBTa and DBTb, along with the structures of reference compounds

including CBP, Firpic, NPB and Bphen as carrier material, emitting

material, and hole and electron transport material.

Twenty-one molecules as carrier materials have been designed by

replacing one CH unit with a nitrogen atom in the parent compound (Figure

11

3.1) Our calculation results indicate that different properties, such as tripletenergy value and excitation energy S1, MO energy level and charge-carryingcapacity are significantly affected when nitrogen atom is introduced into

different positions of DBTa, DBTb and Cz rings of the parent compound.

Table 3.1: The values of HOMO, LUMO energy, ionization energy (IP), electron affinity (EA), hole and electron recombination energy and triplet

energy of the studied compounds (eV).

0,17

0,13

0,042,78

0,17

0,13

0,042,78

0,15

0,13

0,022,69

0,18

0,20

0,022,83

0,18

0,18

0,002,88

D5a -5,28 -1,55 6,3

7 0,41 0,17 0,19 0,02 2,75

D6a -5,23 -1,67 6,3

3 0,46 0,19 0,23 0,05 2,76