共查询到20条相似文献,搜索用时 0 毫秒
1.
Rosenfeld DE Gengeliczki Z Smith BJ Stack TD Fayer MD 《Science (New York, N.Y.)》2011,334(6056):634-639
Ultrafast two-dimensional infrared (2D IR) vibrational echo spectroscopy has proven broadly useful for studying molecular dynamics in solutions. Here, we extend the technique to probing the interfacial dynamics and structure of a silica surface-tethered transition metal carbonyl complex--tricarbonyl (1,10-phenanthroline)rhenium chloride--of interest as a photoreduction catalyst. We interpret the data using a theoretical framework devised to separate the roles of structural evolution and excitation transfer in inducing spectral diffusion. The structural dynamics, as reported on by a carbonyl stretch vibration of the surface-bound complex, have a characteristic time of ~150 picoseconds in the absence of solvent, decrease in duration by a factor of three upon addition of chloroform, and decrease another order of magnitude for the bulk solution. Conversely, solvent-complex interactions increase the lifetime of the probed vibration by 160% when solvent is applied to the monolayer. 相似文献
2.
Remorino A Korendovych IV Wu Y DeGrado WF Hochstrasser RM 《Science (New York, N.Y.)》2011,332(6034):1206-1209
Two-dimensional (2D) vibrational echo spectroscopy has previously been applied to structural determination of small peptides. Here we extend the technique to a more complex, biologically important system: the homodimeric transmembrane dimer from the α chain of the integrin α(IIb)β(3). We prepared micelle suspensions of the pair of 30-residue chains that span the membrane in the native structure, with varying levels of heavy ((13)C=(18)O) isotopes substituted in the backbone of the central 10th through 20th positions. The constraints derived from vibrational coupling of the precisely spaced heavy residues led to determination of an optimized structure from a range of model candidates: Glycine residues at the 12th, 15th, and 16th positions form a tertiary contact in parallel right-handed helix dimers with crossing angles of -58° ± 9° and interhelical distances of 7.7 ± 0.5 angstroms. The frequency correlation established the dynamical model used in the analysis, and it indicated the absence of mobile water associated with labeled residues. Delocalization of vibrational excitations between the helices was also quantitatively established. 相似文献
3.
Jonas DM 《Science (New York, N.Y.)》2003,300(5625):1515-1517
4.
Luntz AC 《Science (New York, N.Y.)》2003,302(5642):70-71
Vibrational excitations of specific bonds in molecules have been used to enhance the reactivity of the molecules in direct gas-phase reactions. In his Perspective, Luntz highlights a report by Beck et al., who show that such vibrational control may also be possible for catalytic reactions at a surface. The authors demonstrate that differently excited deuterated methane molecules have different dissociation probabilities on a nickel surface, even though the energies of the different molecules are similar. 相似文献
5.
6.
Clary DC 《Science (New York, N.Y.)》2005,309(5738):1195-1196
7.
8.
Montgomery J 《Science (New York, N.Y.)》2011,333(6048):1387-1388
9.
10.
11.
Curran DP 《Science (New York, N.Y.)》2008,321(5896):1645-1646
12.
Buriak JM 《Science (New York, N.Y.)》2004,304(5671):692-693
13.
14.
Stahl SS 《Science (New York, N.Y.)》2005,309(5742):1824-1826
15.
16.
17.
Crabtree RH 《Science (New York, N.Y.)》2010,330(6003):455-456
18.
Dai D Wang CC Harich SA Wang X Yang X Der Chao S Skodje RT 《Science (New York, N.Y.)》2003,300(5626):1730-1734
The collision-energy dependence of the state-resolved differential cross section at a specific backward-scattering angle for the reaction H + D2 --> D + HD is measured with the D-atom Rydberg "tagging" time-of-flight technique. The reaction was modeled theoretically with converged quantum scattering calculations that provided physical interpretation of the observations. Oscillations in the differential cross sections in the backward-scattering direction are clearly observed and are attributed to the transition-state structures that originate from the interferences of different quantized transition-state pathways. 相似文献
19.
20.
Driehuys B 《Science (New York, N.Y.)》2006,314(5798):432-433