文献类型：期刊文献

英文题名：Tuneable stimuli-responsive behaviour, spectroscopic signatures and redox properties of indolo[3,2-b]carbazole-based diradicals

作者：Badia-Dominguez, Irene[1];Wang, Deliang[2];Nash, Rosie[3];Jolin, Victor Hernandez[1];Collison, David[4,5];Shanmugam, Muralidharan[4,5];Li, Hongxiang[2,6];Hartl, Frantisek[3];Delgado, M. Carmen Ruiz[1]

机构：[1]Univ Malaga, Dept Phys Chem, Campus Teatinos S-N, E-29071 Malaga, Spain;[2]Chinese Acad Sci, Shanghai Inst Organ Chem, Key Lab Synthet & Selfassembly Chem Organ Funct Ma, Shanghai 200032, Peoples R China;[3]Univ Reading, Dept Chem, Whiteknights, Reading RG6 6DX, England;[4]Univ Manchester, Photon Sci Inst, Manchester M13 9PL, England;[5]Univ Manchester, Dept Chem, Manchester M13 9PL, England;[6]East China Univ Sci & Technol, Inst Fine Chem,Key Lab Adv Mat,Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Frontiers Sci Ctr Materiobiol & Dynam Chem, Shanghai 200237, Peoples R China

年份：2024

卷号：26

期号：41

起止页码：26238

外文期刊名：PHYSICAL CHEMISTRY CHEMICAL PHYSICS

收录：;EI(收录号：20243817072517);WOS:【SCI-EXPANDED(收录号:WOS:001313815700001)】；

基金：The work at the University of Malaga was funded by MICINN/AEI/10.13039/501100011033 (project PID2022-139548NB-I00) and by Junta de Andalucia (FQM-159). The authors would like to thank the computer resources, technical expertise and assistance provided by the SCBI (Supercomputing and Bioinformatics) center and the vibrational spectroscopy (EVI) lab of the Research Central Services (SCAI) of the University of Malaga. We thank EPSRC (EP/W014521/1, EP/X034623/1, EP/V035231/1, NS/A000055/1) and the University of Manchester for access to the EPR Spectroscopy National Research Facility. The work at SIOC was supported by National Natural Science Foundation of China (grants no. 21875279, 22075080 and 21790362). The spectro-electrochemical studies were fully funded by Spectro-electrochemistry Reading (a spinout company of the University of Reading led by F. H.).

语种：英文

外文关键词：Photolysis - Redox reactions

摘要：During the last decade, there has been an increasing interest in the rationalisation of how structural changes stabilise (or destabilise) diradical systems. Demonstrated herein is that indolocarbazole (ICz) diradicals, substituted with dicyanomethylene (DCM) groups, are useful motifs for dynamic covalent chemistry by self-assembling from isolated monomers to cyclophane structures. The comparison of ICz-based systems substituted with DCM groups in para- or meta-positions (p-ICz-CN and m-ICz-CN) and their short-chain carbazole analogues (p-Cz-CN and m-Cz-CN) may identify new potential design strategies for stimuli-responsive materials. The principal objectives of this investigation are the elucidation of (i) the connection between diradical character and the cyclophane stability, (ii) the spatial disposition of the cyclophane structures, (iii) the monomer/cyclophane interconversion both in solution and solid state in response to external stimuli and (iv) the impact that the different pi-conjugation and electronic communication between the DCM terminals exerts on the electronic adsorption of the diradicals and their redox behavior. The spontaneous nature of the cyclophane structure is supported by the negative relative Gibbs free energies calculated at 298 K and experimentally by UV-Vis and Raman spectroscopy of the initial yellow solid powder. The conversion to monomeric species having diradical character was demonstrated by variable-temperature (VT) EPR, UV-Vis, Raman and IR measurements, resulting in appreciable chromic changes. In addition, electrochemical oxidation and reduction convert the cyclophane dimer (m-ICz-CN)2 to the monomer monocations and dianions, respectively. This research demonstrates how the chemical reactivity and physical properties of pi-conjugated diradicals can be effectively tuned by subtle changes in their chemical structures.