The “mini-exciton” in the C10H8 naphthalene pair in a AC10D8 host as studied by electron spin echo and odmr techniques

The effect of spectral diffusion on the phase coherence of phosphorescent triplet spins

“…We employed the rotary echo technique for an investigation of vibronic relaxation in parabenzoquinone [8]. Botter et al [9] have applied the electron spin echo technique to the triplet miniexciton in pairs of naphthalene-h s molecules in a single crystal of naphthalene-d s and recently on triplet excitons in tetrachlorobenzene [10].…”

Theoretical description of quantum effects in multi-chromophoric aggregates

“…If W > 2J , then the better description is hopping, and if W < 2J , the better description is coherent transfer. Botter et al [12] measured the phase memory time of the triplet spins and the zero magnetic field resonance frequencies (using optical detection) between 1.2 K and 4.2 K, from which they were able to conclude that W /2J = 10 −3 at 1.2 K and 10 −2 at 4.2 K, and thus the coherent description of the states and the energy transfer is preferred.…”

Spin-spin and spin-lattice relaxation in the triplet state ofAB-pairs in isotopically mixed crystals of naphthalene

“…The nice separation of the absorption peaks is the result of several factors. First of all the ZF frequencies of the AB-and AA-dimer differ from those of the monomer [2,3]. Secondly there obviously is no energy transfer between these three traps for delay times t d ~ 50 ms.…”

“…In previous experiments [2] it was concluded that the SS relaxation rate T21 was caused by a thermal activation process to the higher Davydov component, where the ZF frequencies are slightly different from those in the lower state. In this analysis however, one overlooked the fact that in addition the spin axes in the two Davydov components have slightly different orientations and that the thermal activation also leads to an appreciable SLR.…”

“…In recent years a number of experimental and theoretical papers has been published in which the problem is investigated whether the triplet excitation of dimers in molecular crystals should be described by a stochastic hopping process or via a coherent, wavelike model [1][2][3][4][5][6]. One of the most thoroughly studied systems is the isotopically mixed crystal of naphthalene.…”