The proton affinity (PA) of cis-4-tert-butylcyclohexyl methyl either with an axial methoxy group is higher by ∼0.1 kcal mol−1 (1 kcal = 4.184 kJ) than the trans isomer with the equatorial ether group. The gas-phase basicity shows a similar small difference of 0.1 kcal mol−1 between the two stereoisomeric ethers. A greater difference in PA has been observed between the stereoisomeric 4-phenylcyclohexyl methyl and ethyl ethers (1.0 and 1.2 kcal mol−1, respectively), in favour of the cis isomers with the equatorial ether groups. The latter result is explained by the internal hydrogen bond with the π-system of the phenyl ring.
顺式4-叔丁基环己基甲基醚(具有轴向甲氧基团)的质子亲和力(PA)比反式异构体(具有赤道醚基团)高约0.1 kcal mol−1(1 kcal = 4.184 kJ)。气相碱性显示出两种立体异构体醚之间也有类似的小差异,为0.1 kcal mol−1。在立体异构体4-苯基环己基甲基和
乙基醚之间观察到了更大的PA差异(分别为1.0和1.2 kcal mol−1),支持赤道醚基团的顺式异构体。后者的结果通过与苯环的π系统形成的内氢键进行了解释。