The present work explores the anharmonic vibrational and electronic spectral features of 6-(dimethylamino) purine (DMAP) compound with the help of the FTIR (4000−400 cm^↓1), FT-Raman (4000−50 cm^↓1) and UV–vis (600−180 nm) spectra as well as DFT calculations. Anharmonic frequencies on the structure of 6-dimethylaminopurine (DMAP) were computed using the generalized vibrational perturbation theory (GVPT2), vibrational self-consistence field (VSCF) theory and correlation-corrected vibrational self consistence field (PT2-VSCF) method in DFT/6−311 G(d,p) framework. The fully anharmonic frequencies calculated using different methods are in remarkable agreement with the experiments as reflected from RMSE and MAD values and show large improvement over the harmonic approximation. The magnitudes of coupling between pairs of normal modes were calculated using quartic force field (2MR-QFF) approximation. The interactions between pair of modes due to mode-mode coupling have significantly affected the vibrational frequencies. The effect of intermolecular interaction (N↓H⋅⋅⋅⋅⋅N) on the geometrical parameters and vibrational frequencies were studied using comparison of results of the monomeric and dimeric structure of the titled molecule. The electronic spectra in the methanol, ethanol and water solvents have been analyzed using the TD-DFT approach and these are compared with the experiment. Furthermore, the associated nonlinear optical (NLO) properties, frontier molecular orbitals and molecular electrostatic potential (MEP) surface analysis have been studied.

本工作借助FTIR（4000-400 cm ^↓1），FT-Raman（4000-50 cm ^↓1）探索了6-（二甲基氨基）嘌呤（DMAP）化合物的非谐振动和电子光谱特征）和UV-vis（600-180 nm）光谱以及DFT计算。使用DFT /中的广义振动微扰理论（GVPT2），振动自洽场（VSCF）理论和相关校正的振动自洽场（PT2-VSCF）方法，计算了6-二甲基氨基嘌呤（DMAP）结构上的非谐频率。 6-311 G（d，p）框架。从RMSE和MAD值可以看出，使用不同方法计算出的完全非谐频率与实验非常吻合，并且在谐波近似上显示出很大的改进。使用四次力场（2MR-QFF）近似计算法线对之间的耦合幅度。由于模式-模式耦合而导致的一对模式之间的相互作用已大大影响了振动频率。通过比较标题分子的单体和二聚体结构的结果，研究了分子间相互作用（N↓H⋅⋅⋅⋅⋅N）对几何参数和振动频率的影响。使用TD-DFT方法分析了甲醇，乙醇和水溶剂中的电子光谱，并将其与实验进行了比较。此外，还研究了相关的非线性光学（NLO）特性，前沿分子轨道和分子静电势（MEP）表面分析。使用TD-DFT方法分析了乙醇和水溶剂，并将其与实验进行了比较。此外，还研究了相关的非线性光学（NLO）特性，前沿分子轨道和分子静电势（MEP）表面分析。使用TD-DFT方法分析了乙醇和水溶剂，并将其与实验进行了比较。此外，还研究了相关的非线性光学（NLO）特性，前沿分子轨道和分子静电势（MEP）表面分析。