Triangular Expanded Hemiporphyrazines: Electronic Structures and Nanoscale Characterization of Their Adlayers on Au(111)

June 7, 2021

Title

Triangular Expanded Hemiporphyrazines: Electronic Structures and Nanoscale Characterization of Their Adlayers on Au(111)

Author

Ana C.C.Bacilla

Year

2021

Journal

Chemical Society of Japan Journals

Abstract

Electronic structures and direct observation of adlayers on Au(111) of triangular expanded hemiporphyrazines that can be classified into azaporphyrinoids and which can trap three transition metal ions are reported. The electronic structure was examined by electronic absorption and magnetic circular dichroism (MCD) spectroscopies and interpreted in conjunction with molecular orbital (MO) calculations. Both metal-free and metallated compounds were 30 π-electron systems with n = 7 in 4n + 2 aromaticity. In addition, calculations of the anisotropy of the induced current density (ACID) and nucleus-independent chemical shift (NICS) were performed. The inner core region of the metal-free compound was weakly anti-aromatic or nonaromatic, but after metal insertion, this region increased aromatic character. The direct observation of adlayers of one of their cobalt and nickel complexes on Au(111) by scanning tunneling microscopy (STM) revealed that these three ions are arranged specifically in the shape of a triangle.

Instrument

J-725, V-570

Keywords

electric, structure, MCD, nucleus-independent chemical shift, NICS