Abstract
Molecular interactions underlying polymorphs of chlorine containing 1,4-naphthoquinone derivatives have been investigated by employing single crystal X-ray, 1H NMR, FTIR and electronic spectra experiments combined with density functional theory. Two polymorphs of 2,3-dichloro-1,4-naphthoquinone possessing (i) triclinic space group P-1(A1 and A3), and (ii) orthorhombic with Pb21a (A2) space group were obtained. The polymorph A3 has two molecules in its asymmetric unit which facilitate CH⋯O interactions engendeing polymeric planar sheets. The two polymorphs of 2-amino-3-chloro-1,4-naphthoquinone reveal monoclinic forms with Pc (B1) and C2/C (B2) space groups. A tetramer of B2 molecule possess NH⋯O interactions. The polymorphs of 2-chloro-3-hydroxy-1,4-naphthoquinone crystallizes in monoclinic space groups Pc (C1) and Pn (C2). Polymeric chain of C2 molecules results via OH⋯O interactions and the chains further are connected through CH⋯Cl and π-π stacking interactions those arise from benzenoid and quinonoid centroid. Moreover A3 facilitates the dimer via the halogen bonding interactions. Furthermore hydrogen bonding renders stability to the dimer C2. On the other hand compound B2 does not favor dimer formation. These inferences based on experimental observations are rationalized through the use of the dispersion corrected M06-2x functional based density functional theory. Further time dependent density functional theory has been used to assign the electronic transitions in UV–visible spectra of A3, B2 and C2.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.