Time-resolved Faradary rotation experiments have demonstrated coherenttransfer of electron spin between CdSe colloidal quantum dots coupled byconjugated molecules. We employ here a Green's function approach, usingsemi-empirical tight-binding to treat the nanocrystal Hamiltonian and ExtendedHuckel theory to treat the linking molecule Hamiltonian, to obtain the coherenttransfer probabilities from atomistic calculations, without the introduction ofany new parameters. Calculations on 1,4-dithiolbenzene and1,4-dithiolcyclohexane linked nanocrystals agree qualitatively with experimentand provide support for a previous transfer Hamiltonian model. We find astriking dependence on the transfer probabilities as a function of nanocrystalsurface site attachment and linking molecule conformation. Additionally, wepredict quantum interference effects in the coherent transfer probabilities for2,7-dithiolnaphthalene and 2,6-dithiolnaphthalene linking molecules. We suggestpossible experiments based on these results that would test the coherent,through-molecule transfer mechanism.
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