The complexation of 2,5-dimethylpyrazine (2,5-DMP) with 2,5-dichloro-3,6-dihydroxy-p-benzoquinone (CLA) leads to the formation of the hydrogen bonded OH⋯N infinite chains without any proton transfer. In the high and medium frequency region of the IR spectra a characteristic Hadži’s trio with maxima at ca. 2400, 1800 and 1150 cm⁻¹ is observed. The infrared, Raman and inelastic neutron scattering (INS) spectra are compared with those calculated by using the DFT methods applied to the crystalline state. The optimization of the structure by using this theoretical approach is also performed. Very good conformity of the experimental and theoretical structures is visible. The reproduction of vibrational spectra is also good except for the low frequency bands related to the CH₃ torsional modes. One gets relatively good agreement by using PWC(dnp) approach. Applications of other theoretical models leads to much higher values of CH₃ torsional frequency.

中文翻译：

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2,5-二氯-3,6-二羟基-对苯醌（CLA）与2,5-二甲基吡嗪（2,5-DMP）1：1加合物的结构和振动光谱

2,5-二甲基吡嗪（2,5-DMP）与2,5-二氯-3,6-二羟基-对苯醌（CLA）的络合导致形成氢键合的OH⋯N无限链而没有任何质子转移。在IR的高和中频区域光谱的特性Hadži的三人在最大值CA。观察到2400、1800和1150cm ^-1。将红外，拉曼和非弹性中子散射（INS）光谱与通过使用应用于结晶态的DFT方法计算得出的光谱进行比较。还使用这种理论方法对结构进行了优化。实验和理论结构的很好的一致性是可见的。除了与CH ₃有关的低频带外，振动频谱的再现效果也很好。扭转模式。通过使用PWC（dnp）方法可以获得相对较好的协议。其他理论模型的应用导致CH ₃扭转频率的值更高。