Abstract

Acknowledgments

Synthesis

Background

Header

Fluorescence

Kevin Schultz, Ph.D.Scott Sibley, Ph.D.Goucher College Chemistry DepartmentThanks to Claasen Fund and Lewent Fund

• 1 displayed a bathochromic shift in acetonitrile suggesting the TICT state exists.

• 2 displayed a slight negative solvatochromism effect in DMSO.

• Further studies could include exploring different solvents with various polarities and/or solid state fluorescence to explore organic LED properties.

Conclusions

Synthesis and investigation of a new dithienyl quinoxaline and its coordination to a Pt(II) centerMichael Morgan*, Dr. Kevin SchultzDepartment of Chemistry, Goucher College

In this study 2,3-bis(2,5-dimethylthien-3-yl)-6-hydroxyquinoxaline was synthesized to further study the twisted intramolecular charge transfer (TICT) state and its absorbance and fluorescence properties. The TICT state generates a dipole moment in the electronic excited state, which can be stabilized in polar solvents causing a change in fluorescence. To investigate possible OLED properties, the 2,3-bis(2,5-dimethylthien-3-yl)-6-hydroxyquinoxaline was then coordinated to a Pt(II) metal center and the differences in absorbance and fluorescence spectra were observed. Further studies could include measuring singlet oxygen conversion efficiency and different transition metal centers.

47%

19%

65%

A twisted intramolecular charge transfer (TICT) state occurs when the HOMO twists out of plane from the LUMO. This creates a temporary node between the HOMO and LUMO from the unsymmetrical orbitals and creates a large dipole moment in the excited state. Previous studies have shown that the TICT state can be stabilized by polar solvents, which causes a red shifted fluorescence emission in relation to the locally excited state.

http://www.mdpi.com/1420-3049/17/12/14067/htm

Absorbance

1

2