1. A chemical bond in which a hydrogen atom of one molecule is attracted to an electronegative atom, especially a nitrogen, oxygen, or flourine atom, usually of another molecule.

• 氢键：一个分子的氢原子与一个带负电的原子相吸引的一种化学键，尤其是一个氮原子，氧原子，或氟原子通常与另外一个分子的原子相吸引