Stable π-Extended Thio[7]helicene-Based Diradical with Predominant Through-Space Spin-Spin Coupling.
Hao WuHiroki HanayamaMax CoehloYanwei GuZe-Hua WuSatoshi TakebayashiGerhard JakobSerhii VasylevskyiDieter SchollmeyerMathias KläuiGrégory PietersMartin BaumgartenKlaus MüllenAkimitsu NaritaZijie QiuPublished in: Journal of the American Chemical Society (2024)
In this work, a novel π-extended thio[7]helicene scaffold was synthesized, where the α-position of the thiophene unit could be functionalized with bulky phenoxy radicals after considerable synthetic attempts. This open-shell helical diradical, ET7H-R , possesses high stability in the air, nontrivial π conjugation, persistent chirality, and a high diradical character ( y 0 of 0.998). The key feature is a predominant through-space spin-spin coupling (TSC) between two radicals at the helical terminals. Variable-temperature continuous-wave electron spin resonance (cw-ESR) and superconducting quantum interference device (SQUID) magnetometry in the solid state reveal a singlet ground state with a nearly degenerate triplet state of ET7H-R . These results highlight the significance of a stable helical diradicaloid as a promising platform for investigating intramolecular TSCs.
Keyphrases
- room temperature
- density functional theory
- energy transfer
- single molecule
- solid state
- transition metal
- ionic liquid
- molecular dynamics
- machine learning
- quantum dots
- minimally invasive
- dna methylation
- estrogen receptor
- single cell
- mass spectrometry
- high throughput
- molecularly imprinted
- high resolution
- neural network
- electron transfer
- monte carlo