Miller Elisa M, Murat Liat, Bennette Nicholas, Hayes Mitchell, Mullin Amy S
Department of Chemistry, Metcalf Center for Science and Engineering, Boston University, Boston, Massachusetts 02215, USA.
J Phys Chem A. 2006 Mar 9;110(9):3266-72. doi: 10.1021/jp054762y.
Strong collisions of highly vibrationally excited picoline isomers and CO2 (00(0)0) were investigated using high resolution transient IR absorption probing to investigate the role of donor state density. Vibrationally excited 3-picoline and 4-picoline (3-methylpyridine and 4 methylpyridine) with E(vib) = 38300 cm(-1) were prepared by 266 nm excitation followed by rapid internal conversion. Transient IR probe measurements of the nascent rotational and translational energy gain in CO2 (00(0)0) show that large DeltaE collisions for 3- and 4-picoline are similar to those for excited 2-picoline. The probability distributions for the large DeltaE energy transfer of the three isomers have similar dependence on DeltaE. The results are compared with other earlier results demonstrating that the shape of the large DeltaE probability distribution correlates with the DeltaE dependence of the donor vibrational state density. The results are discussed in terms of the GRETCHEN model for collisional relaxation.
利用高分辨率瞬态红外吸收探测技术研究了高振动激发的甲基吡啶异构体与二氧化碳（00（0）0）的强碰撞，以探究供体态密度的作用。通过266nm激发随后快速内转换制备了振动激发态的3-甲基吡啶和4-甲基吡啶（3-甲基吡啶和4-甲基吡啶），其振动能量E（vib）= 38300cm-1。对二氧化碳（00（0）0）中新生转动和平动能增益的瞬态红外探针测量表明，3-和4-甲基吡啶的大ΔE碰撞与激发态2-甲基吡啶的相似。三种异构体的大ΔE能量转移概率分布对ΔE具有相似的依赖性。将结果与其他早期结果进行比较，表明大ΔE概率分布的形状与供体振动态密度的ΔE依赖性相关。根据用于碰撞弛豫的GRETCHEN模型对结果进行了讨论。
