2,7-Dicyanomethylenecarbazole Based Biradicaloid and Corresponding Cyclophane Tetramer: Dynamic Interconversion Controlled by External Stimuli

Deliang Wang, Cristina Capel Ferron, Jie Li, Sergio Gamez-Valenzuela, Rocio Ponce Ortiz, Juan T Lopez Navarrete, Victor Hernandez Jolin, Xiaodi Yang, Miriam Pena Alvarez, Valentin Garcia Baonza, Frantisek Hartl, M Carmen Ruiz Delgado, Hongxiang Li

Research output: Contribution to journalArticlepeer-review

Abstract

This work reports on a quinodimethane‐type molecule, 2,7‐dicyanomethylene‐9‐(2‐ethylhexyl)carbazole (1), one of the shortest π‐conjugated biradicaloids reported to be stable in solution under ambient conditions. This carbazole‐based quinoidal precursor is able to form a macrocyclic σ‐bonded tetramer (2). The resolved single‐crystal X‐ray structure of tetramer 2 shows that four molecules of 1 are linked together through four long (CN)2C−C(CN)2 bonds (1.631 Å) resulting from coupling of the unpaired electrons in biradicaloid 1. Dynamic interconversion between monomer 1 and cyclophane tetramer 2 is achieved by reversible cleavage and recovery of the four (CN)2C−C(CN)2 bonds upon soft external stimuli (light absorption, temperature and pressure), which is accompanied by significant color changes. These novel photo‐, thermo‐, and mechanochromic properties expand the versatility of π‐conjugated biradicaloid compounds as novel functional materials that, in combination with spin chemistry and dynamic covalent chemistry, can be relevant in molecular machines, sensors, and switches.
Original languageEnglish
JournalChemistry - A European Journal
Early online date5 Sep 2017
DOIs
Publication statusPublished - 4 Oct 2017

Fingerprint

Dive into the research topics of '2,7-Dicyanomethylenecarbazole Based Biradicaloid and Corresponding Cyclophane Tetramer: Dynamic Interconversion Controlled by External Stimuli'. Together they form a unique fingerprint.

Cite this