Dargent D, Madebène B, Soulard P, Tremblay B, Zins E L, Alikhani M E, Asselin P
Sorbonne Universités, UPMC Université Paris 06, UMR 8233, MONARIS , F-75005, Paris, France.
CNRS, UMR 8233, MONARIS , F-75005, Paris, France.
J Phys Chem A. 2017 Jan 12;121(1):88-97. doi: 10.1021/acs.jpca.6b10492. Epub 2016 Dec 21.
The complexes of diacetyl with water have been studied experimentally by Fourier transform infrared (FTIR) spectroscopy coupled to solid neon matrix and supersonic jet, and anharmonic ab initio calculations. The vibrational analysis of neon matrix spectra over the 100-7500 cm infrared range confirms the existence of two nearly isoenergetic one-to-one (1/1) diacetyl-water S and S isomers already evidenced in a previous argon matrix study. A third form (S) predicted slightly less stable ( J. Mol. Mod. 2015 , 21 , 214 ) is not observed. The correct agreement obtained between neon matrix and anharmonic calculated vibrational frequencies is exploited in several cases to derive band assignments for the vibrational modes of a specific isomer. Thereafter, theoretical x anharmonic coupling constants are used for the attribution of combination bands and overtones relative to the 1/1 dimer. Finally, the most stable isomer of the one-to-two (1/2) diacetyl-water complex is identified in the OH stretching region of water on the grounds of comparison of experimental and calculated vibrational shifts between water dimer and the three most stable 1/2 isomers.
通过与固体氖基质和超音速射流耦合的傅里叶变换红外（FTIR）光谱以及非谐性从头算计算，对二乙酰与水的复合物进行了实验研究。在100 - 7500厘米红外范围内对氖基质光谱进行的振动分析证实了两种能量几乎相等的一对一（1/1）二乙酰 - 水S型和S'型异构体的存在，这在之前的氩基质研究中已得到证明。未观察到预测稳定性稍低的第三种形式（S''）（《分子模型杂志》2015年，21卷，214页）。在几种情况下，利用氖基质与非谐计算振动频率之间获得的正确一致性来推导特定异构体振动模式的谱带归属。此后，理论非谐耦合常数用于归属相对于1/1二聚体的组合带和泛音。最后，根据水二聚体与三种最稳定的1/2异构体之间实验和计算的振动位移比较，在水的OH伸缩区域中确定了一对一二（1/2）二乙酰 - 水复合物的最稳定异构体。
