Influence of the Homopolar Dihydrogen Bonding CH⋅⋅⋅HC on Coordination Geometry: Experimental and Theoretical Studies

Abstract

The reaction of the N-thiophosphorylated thiourea (HOCH2 )(Me)2 CNHC(S)NHP(S)(OiPr)2 (HL), deprotonated by the thiophosphorylamide group, with NiCl2 leads to green needles of the pseudotetrahedral complex [Ni(L-1,5-S,S')2 ]⋅0.5 (n-C6 H14 ) or pale green blocks of the trans square-planar complex trans-[Ni(L-1,5-S,S')2 ]. The former complex is stabilized by homopolar dihydrogen C-H⋅⋅⋅H-C interactions formed by n-hexane solvent molecules with the [Ni(L-1,5-S,S')2 ] unit. Furthermore, the dispersion-dominated C-H⋅⋅⋅ H-C interactions are, together with other noncovalent interactions (C-H⋅⋅⋅N, C-H⋅⋅⋅Ni, C-H⋅⋅⋅S), responsible for pseudotetrahedral coordination around the Ni(II) center in [Ni(L-1,5-S,S')2 ]⋅0.5 (n-C6 H14 ).

Revealing Factors Influencing the Fluorine‐Centered Non‐Covalent Interactions in Some Fluorine‐Substituted Molecular Complexes: Insights from First‐Principles Studies

“…for the C−F⋅⋅⋅F−C interaction, which was responsible for the integrity of a self‐assembled 2D supramolecular architecture using fully fluorinated compounds . The Δ E values of comparable magnitude have been reported for other non‐covalent interactions …”

Non-Covalent Interactions in Hydrogen Storage Materials LiN(CH3)2BH3 and KN(CH3)2BH3

“…Further Valence Bond studies have revealed [78], in line with our conclusions, that, apart from the crucial dispersion term, also the σ/σ*(C-H) polarization/charge transfer and electrostatic contributions are important. Recently, numerous reports are present in the literature on the stabilizing nature of CH¨¨¨HC interactions in various types of hydrocarbons [37,38,[79][80][81][82][83][84][85], as well as their importance in catalysis [42,43,86].…”

“…It is noteworthy that these types of connections are intuitively considered as destabilizing due to the lack of electrostatic attraction between hydrogen atoms-homopolar dihydrogen interactions (especially the intramolecular ones) are still a matter of debate in the literature [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. Very recently more and more evidence has been reported in the literature that highlight the stabilizing nature of homopolar dihydrogen interactions [17,21,29,[36][37][38][39][40][41][42][43][44][45][46]. Accordingly, in this work we provide complementary results which shed light on energetic, quantitative and qualitative characteristics of non-covalent interactions that contribute to the stability of LiN(CH3)2BH3 and KN(CH3)2BH3 crystals.…”

“…It is an important goal as it is known that purely topological QTAIM analysis might provide bond paths between atoms (or fragments) even in situations where the overall interaction energies are positive (destabilizing) [36]. Therefore, we applied the charge and energy decomposition scheme (ETS-NOCV) [47][48][49] which has been proven to provide compact, qualitative and quantitative, descriptions of various types of chemical bonds starting from strong covalent bonds, going through dative connections [47][48][49] and ending up at various non-covalent interactions [7,8,37,50,51]. We applied the ADF program [52][53][54] in which the ETS-NOCV scheme is implemented.…”

Intermolecular interactions in group 14 hydrides: Beyond CH···HC contacts

“…Similarly, Firouzi and Shahbazian explored theoretically the existence of very short CH···HC intramolecular contacts . The additive character of theses interactions has been observed, for instance, in the spatial arrangement of “molecular ladders.” In another interesting work, the stabilization of a pseudotetrahedral Ni II complex was achieved via attractive CH···HC interactions . Recently, the importance of CH···HC contacts in the crystalline phases of several hydrogen storage materials has been pointed out …”