Fluctuating energy level Landau-Teller theory: application to the vibrational energy relaxation of liquid methanol

State-to-state vibrational energy relaxation (VER) rates of the OH-stretch fundamental to select vibrational modes of liquid methanol are presented. The rates are calculated via a modified, fluctuating Landau-Teller (FLT) theory approach, which allow for dynamical vibrational energy level shifts. These rates are then compared to previously published results from Gulmen and Sibert [J. Phys. Chem. A 2004, 108, 2389] for the traditional Landau-Teller (LT) method as well as results calculated through time-dependent perturbation theory (TD), which naturally allow for the fluctuation. For the first time, this method is applied to a polyatomic molecular system, and the FLT theory greatly reduces the discrepancy between the LT and TD results or, at a minimum, is comparable to the LT approach with very little additional computational cost.     

"ortho-Wurster's crowns": synthesis and properties of a novel phenylenediamine-based redox-active macrocyclic ligand

A hybrid, macrocyclic structure based on o-phenylenediamine and a crown ether promotes an intimate mutual interaction with a bound potassium ion in the form of chelation by the redox-active moiety. A general synthetic method and properties are described for the first member of a new class of redox-active, lariat-type macrocycles called the "o-Wurster's crowns".     

Lipophilic derivatives of cyclam as new inhibitors of tumor cell growth

Two new lipophilic tetraazamacrocycles were prepared and, in contrast to non-lipophilic analogs, found to be potent inhibitors of tumor cell growth in vitro with IC50 values below 10 micromolar.     

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Siberian Mathematical Journal -     

An improved error bound for a finite element approximation of a model for phase separation of a multi-component alloy

Using the approach of Rulla (1996 SIAM J. Numer. Anal. 33, 68-87)for analysing the time discretization error and assuming moreregularity on the initial data, we improve on the error boundderived by Barrett and Blowey (1996 IMA J. Numer. Anal. 16,257-287) for a fully practical piecewise linear finite elementapproximation with a backward Euler time discretization of amodel for phase separation of a multi-component alloy.     

Local-mode approach to modeling multidimensional infrared spectra of metal carbonyls

We present a general approach for modeling multidimensional infrared spectra based on a combination of phenomenological fitting and ab initio electronic structure calculations. The vibrational Hamiltonian is written in terms of bilinearly coupled Morse oscillators that represent local carbonyl stretches. This should be contrasted with the previous approach, where the anharmonic Hamiltonian was given in terms of normal-mode coordinates ( Baiz et al. J. Phys. Chem. A 2009 , 113 , 9617 ). The bilinearly coupled Morse oscillator Hamiltonian is parametrized such that the frequencies and couplings are consistent with experiment, and the anharmonicities are computed by density functional theory. The advantages of the local-mode versus normal-mode approaches are discussed, as well as the ability of different density functionals to provide accurate estimates of the model parameters. The applicability and usefulness of the new approach are demonstrated in the context of the recently measured multidimensional infrared spectra of dimanganese decacarbonyl. The shifts in local site frequencies, couplings, and anharmonicities due to hydrogen bonding to the individual carbonyls are explored. It is found that, even though the effect of hydrogen bonding is nonlocal, it is additive.