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 sulfur- and silicon-containing fused rings applied in the fabrication of photovoltaic materials

Specialization: Theoretical and Physical Chemistry

Code: 9.44.01.19

SUMMARY OF CHEMICAL PhD THESIS

The thesis was completed at: Department of Chemistry - Hanoi

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 National University, Hanoi

Review 2: Prof Pham Cam Nam

University of Science and Technology – The University 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 Mai Thanh, and Nguyen Thi Minh Hue "Stability and Semi‐Conductive Property

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 Thi Van Khanh, Hien Nguyen, and Hue Minh Thi Nguyen "A Facile Regioselectively 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 of Structures and Properties of Some Silole Compounds." Vietnam Journal of Chemistry

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

7) Hue Minh Thi Nguyen, Tran Ngoc Dung, Nguyen Van Trang, Ngo Tuan Cuong, Nguyen Van Minh, Hien Nguyen, and Minh Tho Nguyen "Design of Fused Bithiophene Systems Containing Silole and Five-Membered Heterocycles for Optoelectronic Materials." Chemical Physics Letters 784

INTRODUCTION

1 The reason for choosing topic

Organic photovoltaic materials have many advantages over traditional inorganic materials such as low cost, easy fabrication with large surface area and no high temperature required in the production process Organic photovoltaic materials are commonly used in the manufacture of organic light-emitting diodes, organic solar cells, field-effect transistors and sensors Sulfur-containing heterocyclic compounds are one of the important links constituting photovoltaic organic compounds Among them, thiophene ring is the most popular material thanks to its photovoltaic properties and good charge transfer ability The thiophene ring has a pentagonal aromatic ring structure, consisting

of a sulfur atom bonded to a butadiene compound The sulfur atom has two unbonded electron pairs, one of which is involved in the formation of aromaticity for the ring The sulfur atom is highly polar because the outermost electrons orbit the large 3s and 3p orbitals, facilitating electron donation and weak bond formation Furthermore, the sulfur atom can increase its oxidation number thanks to the contribution of the 3d orbital Thanks to the high oxidation numbers, the sulfur atom in the thiophene ring can form functional groups containing oxygen atoms and exhibit special photoelectric properties Since 2005, a number of silicon-containing heterocyclic derivatives have been noticed due to their special electron properties In which, the siole ring is focused on research by scientists Silole has a similar structure to thiophene, the sulfur atom in thiophene is replaced by a silicon atom Silicon-containing heterocycles generally have lower LUMO energies than other heteroatoms, thus leading to a lower HOMO-LUMO gap Therefore, silicon-containing heterocyclic compounds are expected to give good luminescence and charge transfer performance Therefore, this thesis proposes to investigate a number

of condensate systems containing sulfur and silicon to study and compare their photoelectric properties

Calculation software and quantum chemistry methods become an effective tool in studying and investigating molecular structures, chemical reaction mechanisms under different conditions Besides, if using modern calculation methods and high basis functions, the results will be very close to the experiment Within the framework of this thesis, quantum chemical calculations will be used to investigate the substance systems, thereby providing orientation for the experimental synthesis process later At the same time, quantum chemical calculations also help to support and explain experiments as well as investigate properties that are difficult to perform under experimental conditions in Vietnam

2 Research purpose and tasks

a) Research purpose: Simulating and predicting the relationship between the structure and properties of the condensed cyclic system containing thiophene and siole heterocycles by quantum chemical calculations Based on the calculated results, they will guide the experimental synthesis of optimized structures with superior properties that can be applied to manufacturing photovoltaic devices

+ Determining and evaluating the semiconductor and luminescence properties of condensed ring systems containing thiophene and silole heterocycles

+ The results obtained from quantum chemical calculations will guide the selection of substituents and conjugate chain structures to create molecules with desired properties

+ Proposing optimal structures with the most preeminent properties to guide 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 and photoelectric properties of compounds based on the density functional method From the results of theoretical research, select and propose potential compounds for experimental synthesis

4 Scientific and practical significance of the thesis

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

- Research and design some compounds with better photoelectric properties than existing ones theoretically, thereby making suggestions for the synthesis

of photovoltaic organic materials in the future

- Using quantum chemical calculations to confirm the products obtained from organic synthesis

5 New points of the thesis

- Systematic comparison of bithiophene compounds with different substituents 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 Apply computational chemistry to demonstrate the product of the BDT alkenylation reaction

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 scientific and 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 the DFT density functional method Research substance system includes thiophene 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, 190 references Introduction: 4 pages; Chapter 1: 34 pages; Chapter 2: 11 pages; Chapter 3: 70 pages Conclusion and recommendations: 2 pages; List of published 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 or

polymers containing π bonds, which are mainly composed of carbon and

hydrogen 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) Low

production cost, easy to produce on large scale; ii) capable of making thin, light

and flexible devices, iii) easy to customize materials according to the intended

use Despite such advantages, these compounds still have certain limitations,

especially in terms of strength and electrical conductivity

1.2 Theoretical foundations of quantum chemistry

The Schrödinger equation can be solved exactly for electron and

one-nucleus system However, for systems with two or more electrons, exact

solution is not possible due to the interaction between electrons and the

increase of variables in the wave function The density functional method is

proposed to optimize the solution of the Schrödinger equation, especially in

the calculation of large and multi-electron systems Unlike wave

function-based methods, this method is function-based on electron density In this way, the

number of variables in the Schrödinger equation is reduced to only 3, thereby

saving computation time

1.3 Theoretical basis of synthetic heterocyclic derivation

Condensed heterocyclic compounds have attracted the attention of

scientists due to their diverse physical and chemical properties for a long time

The basis for creating this diversity lies in the diversity of substituents The

reactions to add substituents to the existing organic framework are mostly

coupling reactions,i.e new carbon-carbon bond formation reactions such as

Heck, Suzuki, Sonogoshira, Negishi, Kumada, Stille, Tsuji-Trost reactions

Chapter 2 OVERVIEW OF RESEARCH SUBSTANCE SYSTEM

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 the potential compounds for organic photovoltaic materials, thiophene-based compounds represent an irreplaceable role due to their superior photoelectric properties Modulation of the HOMO-LUMO energy of organic photovoltaic materials can be accomplished using thiophene rings or stiff structures with broad π conjugates of thiophene Silole is a heterocyclic compound containing one atom of valence IV silicon, directly bonded to two hydrogen atoms and a butadiene compound The siole molecule has a lower LUMO energy level than other pentacyclic aromatic compounds such as pyrole, furan or thiophene The low LUMO energy level is thought to be caused by the strong interaction between the π* orbital of the butadiene component and the antibonding σ* ortibal of the bond between the silicon atom and the substituent 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 initial structural parameters will be optimized by Gaussian 09 software at the Center for Computational Science, Hanoi National University of Education

After conducting structure optimization with the functional B3LYP, the structures will be calculated the frequency of oscillations at the appropriate set

of basis functions to confirm that the obtained structure is the structure in the ground state

From the optimized structure, the properties of charge transmission,

UV-Vis spectrum, will be calculated on Gaussian 09 software, then processed

results based on Gaussview 6 and Chemcraft software

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 in the

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 of suitable

proportions of n-hexane and ethyl acetate The thin plate will be illuminated

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 with

ethyl acetate, extracted with distilled water to remove the catalyst and

by-products The solution containing the main product was adsorbed onto the

silica gel for purification by column chromatography

The column used was 20 × 50 mm with silica gel of 40-230 mesh The

solvent 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 (M0)

Firpic

Bphen

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

calculation results indicate that different properties, such as triplet energy value and excitation energy S1, MO energy level and charge-carrying capacity 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)

Table 3.1 shows that the calculated energy of the carrier molecules range

from 2.62 eV (compound Cz5) to 2.96 eV (compound D3b) In general, the