An Unconventional Intermolecular Three‐Center N–H … H₂Re Hydrogen Bond in Crystalline [ReH₅(PPh₃)₃]·indole·C₆H₆

Three hydrogen atoms participate in the unusual hydrogen bond in complex 1, which is obtained when the rhenium compound is cocrystallized with indole from benzene. The structure of 1 was elucidated by means of neutron diffraction (HN …︁ HM distances of 1.75 and 2.25 Å). The energy of the hydrogen bond was determined by IR spectroscopy (ΔH° = 4.3 ± 0.5 kcal mol−1). All these values were also reproduced by theoretical calculations. Indole may be a useful additive for crystal growing in general.