酰基硫脲分子内氢键与取代基效应的定量关系

The Relationship Between the Intramolecular Hydrogen Bond of Acylthiourea and Its N-Aromatic Substitutents

对２３个Ｎ－二茂铁甲酰基－Ｎ＇－芳（烷，二茂铁）基硫脲和１４个Ｎ－苯甲酰基－Ｎ＇－芳基硫脲的δ_（β－ＮＨ）与各种取代胺的碱性强度ｐＫ_ｂ及苯环上取代基常数σ进行了系统的定量关系研究。结果表明：酰基硫脲分子内氢键的强弱可由β－氮上氢原子的化学位移值（δ_（β－ＮＨ））来衡量。这类化合物分子内氢键的强弱（δ_（β－ＮＨ））与ｐＫ_ｂ或σ之间有较好的线性关系，从而揭示了此类化合物的分子内氢键与取代基效应之间的定量关系．

The strength of intramolecular hydrogen bond of acyl thiourea can be monitored by the hydrogen chemical shiftδ(β-NH). We measured the physical properties of 23 N-ferrocenoyl-N'-aromatic(also alkyl,ferrocenyl) thioureas and 14 N-benzoyl-N'- aromatic thioureas including δ(β-NH),pKb in relation with the σ-parameter of substituents on the aromatic ring. We found that there are a good relationship between the strength of the intramolecular hydrogen bondδ(β-NH) and pKb or σ-parameter of the substituents, thus the substitution effect toword the hydrogen bonding can be revealed.