Do nitromethane and malononitrile form C–H ⋯ O hydrogen bonds? Implications for molecular recognition by crown ethers

Using ab initio methods at the 6-31G**//6-31G** level of sophistication, we demonstrate that while malononitrile is capable of forming C–H ⋯ O hydrogen bonds with a neutral oxygen donor, nitromethane shows no tendency to form this type of bonding interaction.