title: Control and Switching of Aromaticity in Various All-Aza-Expanded Porphyrins: Spectroscopic and Theoretical Analyses.
abstract: Modification of aromaticity is regarded as one of the most interesting and important research topics in the field of physical organic chemistry. Particularly, porphyrins and their analogues (porphyrinoids) are attractive molecules for exploring various types of aromaticity because most porphyrinoids exhibit circular conjugation pathways in their macrocyclic rings with various molecular structures. Aromaticity in porphyrinoids is significantly affected by structural modification, redox chemistry, NH tautomerization, and electronic states (singlet and triplet excited states). Conversely, aromaticity significantly affects the spectroscopic properties and chemical reactivities of porphyrinoids. In this context, considerable efforts have been devoted to understanding and controlling the aromaticity and antiaromaticity of porphyrinoids. Thus, a series of porphyrinoids are in the limelight, being expected to shed light on this field because they have some advantages to demonstrate the switching of aromaticity; it is possible to control the aromaticity by lowering the temperature, adding and removing the protons of expanded porphyrins, changing the chemical environment, and switching the electronic states (triplet and singlet excited states) by photoexcitation. In this regard, this Review describes the control of aromaticity in various expanded porphyrins from the spectroscopic point of view with assistance from theoretical calculations.
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 120-749, South Korea.
authors.forename: Young Mo
authors.initials: YM
authors.lastname: Sung
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 120-749, South Korea.
authors.forename: Juwon
authors.initials: J
authors.lastname: Oh
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 120-749, South Korea.
authors.forename: Won-Young
authors.initials: WY
authors.lastname: Cha
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 120-749, South Korea.
authors.forename: Woojae
authors.initials: W
authors.lastname: Kim
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 120-749, South Korea.|Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford , South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Lim
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 120-749, South Korea.|Manufacturing Engineering Team, Memory Manufacturing Operation Center, Samsung Electronics , Samsungjeonja-ro 1, Hwasung-si, Gyeonggi-do 18448, South Korea.
authors.forename: Min-Chul
authors.initials: MC
authors.lastname: Yoon
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University , Seoul 120-749, South Korea.
authors.forename: Dongho
authors.identifier: 0000-0001-8668-2644
authors.initials: D
authors.lastname: Kim
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D008962:Models, Theoretical; D015394:Molecular Structure; D011166:Porphyrins / Q000737:chemistry*; D013696:Temperature
chemical_list: D001372:Aza Compounds; D011166:Porphyrins