N ‐Thiophosphorylthioureas RNHC(S)NHP(S)(O i Pr) 2 as an Excellent Platform for Studying the Synergy between Hydrogen‐Hydrogen Bonding and Other Families of Non‐Covalent Interactions

A family of thiourea based derivatives, RNHC(S)NHP(S)(O i Pr) 2 [R = Ph ( YEZNUN ), 2‐MeC 6 H 4 ( AQOYAH ), 2,5‐Me 2 C 6 H 3 ( WARREO ), 2,6‐Me 2 C 6 H 3 ( GUJGUO ), 2,4,6‐Me 3 C 6 H 2 ( AQOYEL ), PhNH ( QORXUR ), 1‐naphthyl ( MOWPEU )], has been studied to understand the synergy between dihydrogen and other (non)conventional non‐covalent interactions. It was established that all monomers are stabilized through intramolecular dihydrogen C–H ··· H–C interactions. Additionally, C–H ··· π interactions are noted in AQOYAH , WARREO , and MOWPEU ; N–H ··· O interactions in AQOYAH , and WARREO ; C–H ··· S interactions in GUJGUO , YEZNUN , and AQOYEL ; N–H ··· S interactions in GUJGUO , AQOYEL , MOWPEU , and YEZNUN ; and N–H ··· N interactions in QORXUR . The crystal structures of all the thioureas are further stabilized by the most pronounced intermolecular C–H ··· H–C interactions followed by N–H ··· S and C–H ··· S with the formation of centrosymmetric R 2 2 (8) dimers. These non‐covalent interactions are augmented by the π ··· π stacking in YEZNUN and MOWPEU ; C–H ··· π in WARREO , GUJGUO , AQOYEL and MOWPEU ; N–H ··· π in QORXUR . The synergy between intra‐ and intermolecular C–H ··· H–C and other types of non‐covalent interactions lead to the extraordinary stability of these systems as indicated by the ETS‐NOCV Scheme Although the London dispersion forces cover ≈ 70–80 % of the overall C–H ··· H–C stabilization, the covalent‐like charge delocalization based on depletion of electron charge from the σ(C–H) orbitals to the inter‐atomic H ··· H region contributes notably up to 15 %.