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4

The description is simplified, but actually fairly accurate. You can find all the details in a specialised NMR book (other general texts usually do not go into much detail). Quantum mechanically, you can show that the precession frequency (Larmor frequency), denoted $\omega_0$, is related to the energy difference between the up and down spin states of a ...


4

Relaxation is often very counterintuitive and isn't a particularly easy subject to understand, so it's not always useful to argue based on what seems to be logical. I'm not sure where you're studying this from, but it seems to be slightly lacking in the detail needed to properly understand what's going on. Here is a brief overview of what's going on, but I ...


3

The point is not really whether chloride or ammonia is a strong or weak field ligand, the point is $\ce{Co^3+}$ is $\mathrm{d^6}$, and virtually all "octahedral" $\mathrm{d^6}$ complexes are low spin - essentially some complexes of $\ce{Fe^2+}$ and a very small number of fluoro complexes of $\ce{Co^3+}$ are the only exceptions to the rule that all $\mathrm{...


2

First recall that the T1 and T2 times reflect different things in the NMR experiment. T1 is the decay of population back to equilibrium and T2 is the decay of the coherence between the spins so we expect them to behave differently in different solvents. Because of the interaction with other nuclear spins in the molecule, and with electrons in the solvent ...


1

The spin operators for the $p^\textrm{th}$ MO are defined as follows: \begin{align} S_{x,p} &= \frac{\hbar}{2} \sum_{\tau,\tau'} c_{p,\tau}^\dagger \hat{\sigma}^x_{\tau,\tau'} c_{p,\tau'}, \\ S_{y,p} &= \frac{\hbar}{2} \sum_{\tau,\tau'} c_{p,\tau}^\dagger \hat{\sigma}^y_{\tau,\tau'} c_{p,\tau'}, \\ S_{z,p} &= \frac{\hbar}{2} \sum_{\tau,\tau'} c_{...


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