What is a transition?

Leveraging Electrons for Electrochemical CO 2 Capture Using a Hemi‐Labile Iron Complex

“…While NMR signals typically broaden at lower temperatures due to reduced molecular mobility, in systems with chemical exchange between different magnetic environments, the spectra are significantly affected by exchange rates, chemical shift differences, and the fraction of molecules in each environment. [44] In the case of two-site exchange, NMR spectra exhibit a typical pattern of line broadening to a coalescence point followed by the sharping and appearance of a second set of signals, as the temperature lowers and the chemical exchange slows down. [45] For instance, 13 C spectra of 1M NA in D 2 O exhibit broadening of C2, C3, C4, and C6, while C1 and C5 signals sharpen with the appearance of new signals at higher frequencies as temperature decreases (See Supporting Figure S9).…”

“…Although we cannot precisely calculate the exchange rates at this point, the clear two‐site exchange pattern suggests that the lifetime of bound NA lies within the millisecond‐to‐second range between 25 and −5 °C. [ 44 ]…”

“…While NMR signals typically broaden at lower temperatures due to reduced molecular mobility, in systems with chemical exchange between different magnetic environments, the spectra are significantly affected by exchange rates, chemical shift differences, and the fraction of molecules in each environment. [ 44 ]…”

Dynamic control of circumrotation of a [2]catenane by acid‐base switching

“…The circumrotation rates of different states of catenane 1 were measured by variable temperature 1 H NMR. [63] Proton H t was selected as the probe to monitor the spectral changes at different temperatures. Figure 3a shows partial 1 H NMR spectra of 1 ‐H 2 ⋅ 6PF 6 at different temperatures.…”

Examining the Electrochemical Properties of Hybrid Aqueous/Ionic Liquid Solid Polymer Electrolytes through the Lens of Composition‐Function Relationships

“…Finally, if k ex ≈ Δ ω , then the exchange between states occurs at similar time lengths as the resonant frequencies of the two states and interactions are observed as a change in the breadth of the peak (broadening) at the resonant frequency. [ 42–44 ] Some complex systems may observe all three scenarios. Therefore, to both qualitatively and quantitatively assess the degree of bound and unbound water, a lineshape analysis (LSA) derived from the obtained 1 H NMR spectra was conducted.…”