Hydrogen bonded complexes of rhodanine with H2X/CH3XH (X = O, S, Se)

Importance of water and intramolecular interaction governs substantial blue shift of Csp2–H stretching frequency in complexes between chalcogenoaldehydes and water

“…For the O-H/O/S/Se/Te H-bonds, the elongation of the O-H bond lengths in the range of 3.4-18.0 m Å and a considerable decrease of its stretching frequencies of 60.0-354.2 cm À1 are observed, which characterize them as red-shiing H-bonds. The large red-shi of the O-H stretching frequencies in O-H/Y (Y ¼ O, S, Se) H-bonds were also observed in the complexes of rhodanine/YH 2 (97-144 cm À1 ), 76 C 6 H 5 OH/Y(CH 3 ) 2 (119-326 cm À1 ), 46 and 4-H-C 6 H 4 -OH + /YH 2 (740-836 cm À1 ). 50 Correlations of the changes of C sp 2-H stretching frequencies with substituents in different complexes are displayed in Fig.…”

Role of O–H⋯O/S conventional hydrogen bonds in considerable Csp2–H blue-shift in the binary systems of acetaldehyde and thioacetaldehyde with substituted carboxylic and thiocarboxylic acids

“…38,46,70 It is found that the contribution to the RZ–Z stabilization is larger for C sp 2 –H⋯O2/O–H⋯O7 hydrogen bonds than that for C sp 2 –H⋯S2/O–H⋯S7. With the different substitution of Z2 or Z7 atoms, AIM data shows a larger strength of the C sp 2 –H⋯O2 hydrogen bond compared to C sp 2 –H⋯S2, 76,77 and a larger strength of the O–H⋯O7 bond in comparison with O–H⋯S7 one. 78,79 The second-order correlations between the individual energy of hydrogen bond ( E HB ) with the value of electron density ( ρ ( r C )) at the BCP and the distance H⋯Z( r (H⋯Z)) are plotted in Fig.…”

Investigation of intramolecular hydrogen bonding in naphthoquinone derivatives by quantum chemical calculations

“…Similar result has also been obtained in our previous work. [37] Among all the studied systems, 4,8-DHNQ is having highest hydrogen bond strength, and 5,8-DANQ has the lowest hydrogen bond strength. Figure 2 shows the exponential relationship between the ρ (BCP) and the hydrogen bond distances, which is in good agreement with previous reports for hydrogen bonds.…”