The Weakness of B−H⋅⋅⋅π Interactions: Much Softer than a Hydrogen Bond

Recently, a new type of non‐covalent interaction, the B?H???π interaction, was introduced. Nevertheless, the unique determination of individual, non‐covalent bond strengths in complex molecular systems is a non‐trivial task with often controversial results. The utilization of generalized compliance constants (relaxed force constants) is proposed as unique bond‐strength descriptors for classical and non‐classical hydrogen bonds. The strength of recently proposed B?H???π bonds is discussed.