Elektron Veren Gruplar (–NH₂) ve (–Cl) Sübstitüentlerinin Bağlanmasıyla Pirolün İletkenlik Özelliklerinin İncelenmesi

Year 2025, Volume: 9 Issue: 2, 154 - 173, 30.09.2025

Zafer Maşlakcı , Ayşin Adin

https://doi.org/10.30516/bilgesci.1742388

Abstract

Bilim ve teknolojideki hızlı gelişmeler, farklı fiziksel ve kimyasal özelliklere sahip, üretimi kolay ve geniş uygulama alanlarına hitap eden yeni malzemelerin üretilmesi gerekliliğini doğurmuştur. İletken polimerler, iletkenlik özelliklerini değiştirmek amacıyla kullanılabilir. Bu değişimi sağlamak için kullanılan yöntemlerden biri, monomere farklı sübstitüentler eklemektir. Bu amaçla, 1-(4-metilfenil)pirol ve 3-(4-metilfenil)pirol bileşiklerinde, fenil grubundaki metil gruplarının yerine elektron veren gruplar (–NH₂ ve –Cl) yerleştirilerek HOMO-LUMO aralığı ölçülmüştür. Sübstitüe edilmiş fenil grubunun azot pozisyonuna mı yoksa karbon pozisyonuna mı bağlandığı durumlar, Gaussian16 yazılım paketi kullanılarak hesaplanmıştır. Elde edilen yapılar, zincir uzunluğu n=1’den n=5’e kadar artırılarak optimize edilmiştir. Ayrıca, etkileşimlerin topolojik özellikleri, elektron yoğunluklarına göre karşılaştırılmıştır. Elektron veren grupların HOMO enerjisini artırıp LUMO enerjisini düşürdüğü, böylece bant aralığını daraltarak iletkenliği artırdığı gözlemlenmiştir. Elektron yoğunluklarının iletkenliğe zıt yönde değişim göstermesi, AIM teorisinin iletkenliğin belirlenmesinde tercih edilebilir ve güvenilir bir yöntem olduğunu ortaya koymaktadır. –Cl ve –NH₂ sübstitüentlerinin eklenmesi, IR spektral özelliklerinde önemli değişikliklere yol açmaktadır. Takip eden polimerleşme ile bant yoğunluklarında artış ve genişleme gözlemlenmiş; 1- ve 3- izomerik formlar arasında küçük fakat fark edilir frekans ve şiddet kaymaları tespit edilmiştir.

Keywords

Homo-Lumo , Pirol , Sübstitüent etkisi , Topolojik özellikler

Project Number

1919B012215276

Investigation of the Conductivity Properties of Pyrrole with the Attachment of Electron-Donating Groups (–NH2) and (–Cl) as Substituents

Abstract

The rapid advancements in science and technology have created the need for the production of new materials with distinct physical and chemical properties, ease of production, and a wide range of applications. Conductive polymers can be used to modify conductivity properties. One method for achieving this modification is by adding different substituents to the monomer. For this purpose, the HOMO-LUMO gap was measured by substituting electron-donating groups (–NH2 and –Cl) in place of the methyl groups in the phenyl groups of 1-(4-methylphenyl)pyrrole and 3-(4-methylphenyl)pyrrole. The interactions when the substituted phenyl group was attached at the nitrogen position or the carbon position were calculated using the Gaussian16 software package. The configurations obtained were optimized by increasing the chain length from n=1 to n=5. Additionally, the topological properties of the interactions were compared based on electron densities. It was observed that electron-donating groups increased the HOMO energy and decreased the LUMO energy, thereby reducing the band gap and enhancing conductivity. The fact that electron densities are in the opposite direction to conductivity shows that AIM theory is a preferable and reliable method for determining conductivity. The incorporation of –Cl and –NH₂ substituents leads to significant changes in the IR spectral properties. Subsequent polymerization results in changes in band intensity and broadening, with small but noticeable frequency and intensity shifts observed between the 1 and 3 isomeric forms.

Keywords

Homo-Lumo , Pyrrole , Substituent effect , Topological properties

Supporting Institution

TÜBİTAK 2209-A University Students Research Projects Support Program

Project Number

1919B012215276

Thanks

This study was supported within the scope of the TÜBİTAK 2209-A University Students Research Projects Support Program under project number 1919B012215276. We thank TÜBİTAK for its support. The authors would like to thank Prof. Dr. Nevin Aytemiz for her support in using the AIMAll package program. The numerical calculations in this article were partially performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA resources).

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