Monte Carlo simulation of DNMR spectra of coupled spin systems

Studies of Ligand Exchange in N-Heterocyclic Carbene Silver(I) Complexes

“…The use of NMR line-shape phenomena to study dynamic processes in spin systems has a long history both in organometallic chemistry and in studies of ligand exchange for Ag complexes. ,,− By matching simulated spectra to observed spectra, it is possible to determine kinetic parameters for these exchange processes. In this work, we matched the observed VT NMR spectra with the simulated spectra calculated using MEXICO, a computer program for NMR chemical exchange line-shape calculation. ,, The calculated rate constants obtained in this way were then used with the Eyring equation to determine the activation parameters for the exchange process.…”

Fast calculation of DNMR spectra on CUDA‐enabled graphics card

“…The Monte Carlo calculation of DNMR spectra of coupled spin systems is based on the simulation of the behavior of spin sets. A spin set is an ordered set of S 1 , S 2 , … S n nuclei that are uncoupled to any other nuclei apart from the elements of the spin set 20, 21. These spin sets appear in several chemical environments due to the dynamic processes (e.g., conformational motions, equilibrium reactions).…”

“…The behavior of the spin system is characterized by the reduced spin density matrix, ρ = |ψ i 〉〈ψ j |, which contains the densities of the possible nuclear spin states, |ψ i 〉 (see ref 21. for details).…”

“…An alternative theory of dynamic NMR describes the behavior of individual spins 17, 18. Recently, we have improved this model to describe the NMR lineshapes of coupled spin systems as well 19–21. This extended theory is based on the kinetic Monte Carlo simulation of exchange processes and the propagation of the individual density matrices of spin sets.…”

“…The most important advantage of this new program, Pro pagators and Mo nte C arlo S imulation (ProMoCS) is that the study of larger spin systems and multisite exchanges become available. The Monte Carlo method needs several hundreds of spectra, appropriately calculated;19 therefore, both versions of ProMoCS written in Java or C (ProMoCS‐Java and ProMoCS‐C) are slower than their counterparts solving the Liouville‐von Neumann equation (e.g., MEXICO16).…”