出典:Wikipedia
出典:『Wikipedia』 (2011/05/31 04:09 UTC 版)
The bifluoride, or hydrogen(difluoride) ion is the species HF2−. This centrosymmetric triatomic anion features the strongest known hydrogen bond, with an F−H length of 114 pm and a bond strength of >155 kJ mol−1. A molecular orbital diagram reveals the atoms to be held together by a 3-center 4-electron bond. Hydrogen(difluoride) is written as one word because it is an anion. Hydrogen difluoride would imply an electrically neutral compound, HF2, which does not exist. It is isoelectronic with the hypothetical compound helium difluoride, HeF2, which also does not exist, and the fluoroheliate anion, FHeO−, whose existence is suspected.