N-H stretching modes of adenosine monomer in solution studied by ultrafast nonlinear infrared spectroscopy and ab initio calculations.
The N-H stretching vibrations of adenine, one of the building blocks of DNA, are studied by combining infrared absorption and nonlinear two-dimensional infrared spectroscopy with ab initio calculations. We determine diagonal and off-diagonal anharmonicities of N-H stretching vibrations in chemically modified adenosine monomer dissolved in chloroform. For the single-quantum excitation manifold, the normal mode picture with symmetric and asymmetric NH(2) stretching vibrations is fully appropriate. For the two-quantum excitation manifold, however, the interplay between intermode coupling and frequency shifts due to a large diagonal anharmonicity leads to a situation where strong mixing does not occur. We compare our findings with previously reported values obtained on overtone spectroscopy of coupled hydrogen stretching oscillators.
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2 A, D-12489 Berlin, Germany.
Christian
C
Greve
Nicholas K
NK
Preketes
Rene
R
Costard
Benjamin
B
Koeppe
Henk
H
Fidder
Erik T J
ET
Nibbering
Friedrich
F
Temps
Shaul
S
Mukamel
Thomas
T
Elsaesser
D000241:Adenosine / Q000737:chemistry*; D002725:Chloroform / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D007700:Kinetics; D008956:Models, Chemical; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D011789:Quantum Theory; D012996:Solutions; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics; D013997:Time Factors; D014732:Vibration; D014867:Water / Q000737:chemistry
D012996:Solutions; D014867:Water; D002725:Chloroform; D006859:Hydrogen; D004247:DNA; D000241:Adenosine; D009584:Nitrogen