Abstract The present work deals with the synthesis as well as molecular modeling and vibrational spectroscopic analysis of two biorelevant molecules, namely N-n-butyl, S-2-nitro-1-phenylethyl dithiocarbamate and N-n-butyl, S-2-nitro-1-(4-flurophenyl)ethyldithiocarbamate in gas phase. The optimization of the molecular structures of these compounds was performed at Density Functional Theory with exchange functional B3LYP and Hartree-Fock theory. The customary basis set 6-31++G(d,p) was employed during computations at both the level. The experimental FTIR spectra of both these two compounds were recorded in range 4000–400 cm-1 to correlate with the calculated spectra of the compounds. The normal coordinate analysis (NCA) method was used for the calculation of potential energy distributions. Most of the DFT calculated frequencies were found to agree with the experimental FTIR frequencies. To ensure the stability of electronic structures of these compounds the natural bond orbital analysis (NBO) for each compound was also performed and the analysis revealed that the intramolecular interactions resulting from overlapping of bonding and antibonding orbitals provoke the intramolecular charge transfer (ICT) causing stabilization of the system. The frontier bond orbital analysis was also performed to study the interaction profile of the compounds.

中文翻译：

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分子的合成、结构和振动光谱研究：Nn-丁基，S-2-硝基-1-苯基乙基二硫代氨基甲酸酯和 Nn-丁基，S-2-硝基-1-(4-氟苯基)乙基二硫代氨基甲酸酯

摘要 目前的工作涉及两种生物相关分子的合成、分子建模和振动光谱分析，即 Nn-丁基，S-2-硝基-1-苯基乙基二硫代氨基甲酸酯和 Nn-丁基，S-2-硝基-1- (4-氟苯基)乙基二硫代氨基甲酸酯在气相中。这些化合物的分子结构的优化是在密度泛函理论中使用交换泛函 B3LYP 和 Hartree-Fock 理论进行的。在这两个级别的计算过程中都采用了惯用的基组 6-31++G(d,p)。这两种化合物的实验 FTIR 光谱都记录在 4000-400 cm-1 范围内，以与计算的化合物光谱相关联。正态坐标分析（NCA）方法用于计算势能分布。发现大多数 DFT 计算频率与实验 FTIR 频率一致。为了确保这些化合物的电子结构的稳定性，还对每种化合物进行了自然键轨道分析 (NBO)，分析表明，由于键和反键轨道重叠导致的分子内相互作用引发了分子内电荷转移 (ICT)，从而导致稳定性系统的。还进行了前沿键轨道分析以研究化合物的相互作用曲线。为了确保这些化合物的电子结构的稳定性，还对每种化合物进行了自然键轨道分析 (NBO)，分析表明，由于键和反键轨道重叠导致的分子内相互作用引发了分子内电荷转移 (ICT)，从而导致稳定性系统的。还进行了前沿键轨道分析以研究化合物的相互作用曲线。为了确保这些化合物的电子结构的稳定性，还对每种化合物进行了自然键轨道分析 (NBO)，分析表明，由于键和反键轨道重叠导致的分子内相互作用引发了分子内电荷转移 (ICT)，从而导致稳定性系统的。还进行了前沿键轨道分析以研究化合物的相互作用曲线。