An Experimental Exploration of C−H⋅⋅⋅X Hydrogen Bond in [CHCl₃−X(CH₃)₂] Complexes (X=O, S, and Se)

Abstract

Among the conglomeration of hydrogen bond donors, the C−H group is prevalent in chemistry and biology. In the present work, CHCl3 has been selected as the hydrogen bond donor and are X(CH3)2 are the hydrogen bond acceptors. Formation of C−H⋅⋅⋅X hydrogen bond under the matrix isolation condition is confirmed by the observation of red‐shift in the C−H stretching frequency of CHCl3 and comparison with the simulated spectra. Stabilisation energy of all the three complexes is almost equal although the observed red‐shift for the C−H⋅⋅⋅O complex is less compared to the C−H⋅⋅⋅S/Se complexes. The nature and origin of the hydrogen bond have been delineated using Natural Bond Orbital, Atoms in Molecules, Non‐Covalent Interaction analyses, and Energy Decomposition Analysis. Charge transfer is found to be proportional to the observed red‐shift. This work provides the first impression of C−H⋅⋅⋅Se hydrogen bond and its comparison with C−H⋅⋅⋅O/S hydrogen bond interaction under experimental condition.

Characteristics of nonconventional hydrogen bonds and stability of dimers of chalcogenoaldehyde derivatives: a noticeable role of oxygen compared to other chalcogens

“… 52–54 Very recently, the existence of C sp –H and C sp 3 –H stretching frequency red-shifts of nonconventional C sp –H⋯Se and C sp 3 –H⋯Se hydrogen bonds has been theoretically and experimentally discovered in complexes of C 8 H 6 and Se(CH 3 ) 2 , 55 Q 3 CH and SeH 2 (Q = Cl, H, and F), 56 and CHCl 3 and Se(CH 3 ) 2 . 57 It is noteworthy that a very large C sp 2 –H blue-shift of 104.5 cm −1 was reached in the complexes between CH 3 CHZ and RCZOH (R = H, CH 3 , F; Z = O, S). 54 The nonconventional C sp 2 –H⋯Se/Te and Z–H⋯Se/Te hydrogen bonds have recently been found in some systems.…”

Computational Insight into the Nature and Strength of the π-Hole Type Chalcogen∙∙∙Chalcogen Interactions in the XO2∙∙∙CH3YCH3 Complexes (X = S, Se, Te; Y = O, S, Se, Te)

“…This can be primarily attributed to the fact that the polarizability of the X atom becomes larger, and its electronegativity becomes smaller as the size of the chalcogen atom increases. hydrogen bonds [57,58], chalcogen bonds [20,26], and pnictogen bonds [59]. Additionally, the molecular electrostatic surface potential (MESP) [60], quantum theory of atoms in molecules (QTAIM) [61], non-covalent interaction plot (NCIplot) [62], natural bond orbital (NBO) [63], and symmetry-adapted perturbation theory (SAPT) [64] analyses were also conducted to gain a deeper understanding of the π-hole-type chalcogen•••chalcogen interactions.…”

“…In addition, as far as we know, no studies have been reported on such interactions containing the heavy chalcogen atom Te as a ChB donor or ChB acceptor. Herein, we used quantum chemical calculations to systematically investigate the strength and nature of the π-hole-type intermolecular chalcogen•••chalcogen interactions in the model complexes between XO 2 (X = S, Se, Te) and CH 3 YCH 3 (Y = O, S, Se, Te), which was frequently used as a nucleophile to engage in various NCIs like hydrogen bonds [57,58], chalcogen bonds [20,26], and pnictogen bonds [59]. Addition-ally, the molecular electrostatic surface potential (MESP) [60], quantum theory of atoms in molecules (QTAIM) [61], non-covalent interaction plot (NCIplot) [62], natural bond orbital (NBO) [63], and symmetry-adapted perturbation theory (SAPT) [64] analyses were also conducted to gain a deeper understanding of the π-hole-type chalcogen•••chalcogen interactions.…”

Unveiling the Nature and Strength of Selenium-Centered Chalcogen Bonds in Binary Complexes of SeO2 with Oxygen-/Sulfur-Containing Lewis Bases: Insights from Theoretical Calculations

“…These NCIs are crucial for the stability, structure, and function of compounds and proteins containing selenium, as well as for molecular recognition [10][11][12][13][14][15][16][17]. Theoretical and experimental studies have demonstrated that selenium can serve as a proton acceptor to engage in D-H•••Se (D = C, N, O, S) hydrogen bonds (HBs) [18][19][20][21][22][23] and also act as a proton donor to form Se-H•••A (A = N, O, S, Se, π) HBs [24][25][26][27][28]. These selenium-centered hydrogen bonds (SeCHBs) are a significant class of seleniumcontaining NCIs.…”