Diabatic states for donor (D) and acceptor (A) interactions in electron transfer (ET) processes are formulated and evaluated, along with coupling elements (H DA ) and effective D/A separation distances (r DA ), for reduced electronic spaces of variable size, using the generalized Mulliken Hush model (GMH), applicable to an arbitrary state space and nuclear configuration, and encompassing Robin-Day class III and as well as class II situations. Once the electronic state space is selected (a set of n g 2 adiabatic states approximated by an orbital space based on an effective 1-electron (1-e) Hamiltonian), the charge-localized GMH diabatic states are obtained as the eigenstates of the dipole moment operator, with rotations to yield locally adiabatic states for sites with multiple states. The 1-e states and energies are expressed in terms of Kohn-Sham orbitals and orbital energies. Addressing questions as to whether the estimate of H DA "improves" as one increases n, and in what sense the GMH approach "converges" with n, we carry out calculations for three mixed-valence binuclear Ru complexes, from which we conclude that the 2-state (2-st) model gives the most appropriate estimate of the effectiVe coupling, similar (to within a rms deviation of e15%) to coupling elements obtained by superexchange correction of H DA values based on larger spaces (n ) 3-6), and thus yielding a quasi-invariant value for H DA over the range explored in the calculations (n ) 2-6). An analysis of the coupling and associated D and A states shows that the 2-st coupling involves crucial mixing with intervening bridge states (D and A "tails"), while increasingly larger state spaces for the same system yield increasingly more localized D and A states (and weaker coupling), with H DA tending to approach the limit of "bare" or "through space" coupling. These results help to reconcile seemingly contradictory assertions in the recent literature regarding the proper role of multistate frameworks in the formulation of coupling for both intra-and intermolecular ET systems.The present results are compared in detail with other reported results.

Instances of discrete states coupled to continua are physically ubiquitous. Numerical simulations of such systems often rely on a discrete representation of the continuum by a large but finite set of discrete levels, or "pseudostates." In this paper, we develop a method based on the prior work of Kazansky to derive an efficient discrete representation of an arbitrary continuum. For several test cases, our method allows the simulation of non-Markovian decay dynamics with a far smaller set of pseudostates than previously required. We also discuss how this approach can be viewed as a "complex scaling" of the band energy coordinate.

This paper explores Fano resonances due to non-adiabatic coupling of vibrational modes and the electron continuum in dipole-bound anions. We adopt a simple one-electron model consisting of a point dipole and an auxiliary potential to represent the electron interaction with the neutral core. Nuclear motion is added by assuming that harmonic vibrations modulate the dipole moment. When the model is parameterized to simulate key features of the water tetramer anion, the resultant photodetachment lineshape closely resembles that observed experimentally and analyzed as a Fano resonance with a parameter q close to -1. Other parameterizations are explored for the model and it is found that large changes in the auxiliary potential are required to change the sign of q. This is consistent with the experimental finding that q is negative for all water cluster sizes studied.

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Synthesis of C-Aryl-∆ 2,3 -glycopyranosides via Uncatalyzed Addition of Triarylindium Reagents to Glycals. -The title reaction produces glycopyranosides in good yields and diastereoselectivity. The method can be extended to trivinyl-and tris(alkynyl)indiums with similar results. -(PRICE, S.; EDWARDS, S.; WU, T.; MINEHAN*, T.; Tetrahedron Lett. 45 (2004) 27, 5197-5201; Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USA; Eng.) -Mais 41-193