论文部分内容阅读
本文通过羟基的化学位移(δ_OH),解离常数(pK_α),质谱外光谱的测量以及PM0和HMO计算,较详细地研究了分子内氢键强度和偶氮-醌腙式互变异构与分子结构的关系.结果表明,内氢键强度(以⊿δ_OH和⊿pK_α来衡量)与PMO和HMO计算的内氢键稳定化能(⊿BE_H)和给予氮原子上的电荷密度(q_N)有正比关系.HMO计算还表明,醌腙式异构体的稳定性(⊿BE_A-H)与⊿BE_H有很好的线性关系.当有内氢键存在时,化合物4～7的醌腙式比偶氮式稳定;而在气体离子态时,HMO计算和质谱结果都表明1～7皆以偶氮式更为稳定,且质谱碎片分布和HMO计算的断裂键的键序(P_xy)有近似的直线关系.所有的实验结果和分子轨道计算结果都证实了1～3具有偶氮式,4～7为偶极偶氮式结构.
In this paper, the intramolecular hydrogen bond strength and azo-quinone hydrazone tautomerism were studied in detail by chemical shifts (δ_OH), dissociation constants (pK_α), extra-MS spectra and calculations of PMO and HMO. Molecular structure.The results show that the internal hydrogen bond strength (⊿BE_H) and the charge density (q_N) on the nitrogen atom calculated by the internal hydrogen bond strength (measured by ⊿δ_OH and ⊿pK_α) and the PMO and HMO are HMO calculation also showed that the stability of the quinone hydrazone isomer (⊿BE_A-H) and ⊿BE_H has a good linear relationship.When there is an internal hydrogen bond, the compound 4 ~ 7 quinone hydrazone ratio While in the gas ionic state, both HMO calculation and mass spectrometry results show that 1 ~ 7 are more stable with azo, and the mass spectrum fragment distribution and the HMO calculated bond order (P_xy) are similar All the experimental results and molecular orbital calculations confirm that 1 ~ 3 have azo and 4 ~ 7 are dipolar azo structures.