A detailed spectroscopic study on ethyl methyl carbonate, a green solvent, has been carried out by recording vacuum ultraviolet and infrared spectra. The vacuum ultraviolet photoabsorption spectrum is recorded using synchrotron radiation from Photophysics beamline at the Indus-1 synchrotron radiation source at RRCAT, Indore, India in the wavelength region of 7–11.5 eV. Infrared spectra in gas phase as well as matrix isolated case are recorded using an indigenously developed laboratory low temperature experimental facility and a Fourier transform infrared spectrometer in the 500–4000 cm⁻¹ region. Geometry optimization, vibrational frequency analysis of neutral & ionized ethyl methyl carbonate and electronic excited state energy information has been obtained using quantum chemical calculations. The observed ir spectral features could be assigned to the fundamental vibrational modes of the molecule. The vacuum ultraviolet region comprising a broad continuum is assigned to valence transitions having high oscillator strengths and overlying weak bands to ns, np, nd type Rydberg transitions. Potential energy curves of the ground and first few low lying excited states generated provided additional insights into their nature and further interpretation of observed experimental spectra. In this paper we report the first electronic absorption spectrum in 7 to 11.5 eV region, its spectroscopic analysis and identification of vibrational modes in the infrared spectra for ethyl methyl carbonate. Results of quantum chemical simulations carried out to obtain nature of excited states, energies and vibrational frequencies using GAMESS (USA) quantum chemistry code are also reported in this paper.

通过记录真空紫外和红外光谱，对绿色溶剂碳酸甲乙酯进行了详细的光谱研究。真空紫外光吸收光谱是使用来自印度印多尔 RRCAT 的 Indus-1 同步辐射源的光物理光束线的同步辐射在 7-11.5 eV 的波长范围内记录的。使用自主开发的实验室低温实验设备和傅立叶变换红外光谱仪在 500–4000 cm ^{-1 范围}内记录气相和基质隔离情况下的红外光谱地区。使用量子化学计算获得了几何优化、中性和电离碳酸甲乙酯的振动频率分析和电子激发态能量信息。观察到的红外光谱特征可以分配给分子的基本振动模式。包含宽连续谱的真空紫外区被分配给具有高振子强度和覆盖弱带的价跃迁至 ns、np、nd 型里德堡跃迁。地面的势能曲线和最初产生的几个低位激发态提供了对其性质的额外见解，并进一步解释了观察到的实验光谱。在本文中，我们报告了 7 到 11.5 eV 区域的第一个电子吸收光谱，其光谱分析和识别碳酸甲乙酯红外光谱中的振动模式。本文还报告了使用 GAMESS（美国）量子化学代码为获得激发态、能量和振动频率的性质而进行的量子化学模拟的结果。