Exploring bismuth coordination complexes as visible-light absorbers: synthesis, characterization, and photophysical properties

DOI: 10.1021/acs.inorgchem.3c03290

Authors: Harsh Bhatia (University College London) , Junjun Guo (University College London) , Christopher N. Savory (University College London) , Martyn Rush (Polysolar Ltd) , David I. James (Johnson Matthey Technology Centre) , Avishek Dey (University College London) , Charles Chen (University College London) , Dejan-Krešimir Bučar (University College London) , Tracey M. Clarke (University College London) , David O. Scanlon (University College London; Diamond Light Source) , Robert G. Palgrave (University College London) , Bob C. Schroeder (University College London)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Inorganic Chemistry , VOL 51

State: Published (Approved)
Published: December 2023

Abstract: Bismuth-based coordination complexes are advantageous over other metal complexes, as bismuth is the heaviest nontoxic element with high spin–orbit coupling and potential optoelectronics applications. Herein, four bismuth halide-based coordination complexes [Bi2Cl6(phen-thio)2] (1), [Bi2Br6(phen-thio)2] (2), [Bi2I6(phen-thio)2] (3), and [Bi2I6(phen-Me)2] (4) were synthesized, characterized, and subjected to detailed photophysical studies. The complexes were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and NMR studies. Spectroscopic analyses of 1–4 in solutions of different polarities were performed to understand the role of the organic and inorganic components in determining the ground- and excited-state properties of the complexes. The photophysical properties of the complexes were characterized by ground-state absorption, steady-state photoluminescence, microsecond time-resolved photoluminescence, and absorption spectroscopy. Periodic density functional theory (DFT) calculations were performed on the solid-state structures to understand the role of the organic and inorganic parts of the complexes. The studies showed that changing the ancillary ligand from chlorine (Cl) and bromine (Br) to iodine (I) bathochromically shifts the absorption band along with enhancing the absorption coefficient. Also, changing the halides (Cl, Br to I) affects the photoluminescent quantum yields of the ligand-centered (LC) emissive state without markedly affecting the lifetimes. The combined results confirmed that ground-state properties are strongly influenced by the inorganic part, and the lower-energy excited state is LC. This study paves the way to design novel bismuth coordination complexes for optoelectronic applications by rigorously choosing the ligands and bismuth salt.

Subject Areas: Chemistry

Facility: HarwellXPS

Added On: 16/12/2023 16:05

Documents:
bhatia-et-al-2023-exploring-bismuth-coordination-complexes-as-visible-light-absorbers-synthesis-characterization-and.pdf

Discipline Tags:

Molecular Complexes Physical Chemistry Chemistry Inorganic Chemistry

Technical Tags: