Abstract
The structures of the hydrogen-bonded 1:1 co-crystal of chloranilic acid (systematic name: 2,5-di-chloro-3,6-dihy-droxy-1,4-benzo-quinone) with ethyl-eneurea (systematic name: imidazolidin-2-one), C6H2Cl2O4·C3H6N2O, (I), and the 1:2 co-crystal of chloranilic acid with hydantoin (systematic name: imidazolidine-2,4-dione), C6H2Cl2O4·2C3H4N2O2, (II), have been determined at 180 K. In the crystals of both compounds, the base mol-ecules are in the lactam form and no acid-base inter-action involving H-atom transfer is observed. The asymmetric unit of (I) consists of two independent half-mol-ecules of chloranilic acid, with each of the acid mol-ecules lying about an inversion centre, and one ethyl-eneurea mol-ecule. The asymmetric unit of (II) consists of one half-mol-ecule of chloranilic acid, which lies about an inversion centre, and one hydantoin mol-ecule. In the crystal of (I), the acid and base mol-ecules are linked via O-H⋯O and N-H⋯O hydrogen bonds, forming an undulating sheet structure parallel to the ab plane. In (II), the base mol-ecules form an inversion dimer via a pair of N-H⋯O hydrogen bonds, and the base dimers are further linked through another N-H⋯O hydrogen bond into a layer structure parallel to (01). The acid mol-ecule and the base mol-ecule are linked via an O-H⋯O hydrogen bond.
Highlights
Chloranilic acid, a dibasic acid with hydrogen-bond donor as well as acceptor groups, appears attractive as a template for generating tightly bound self-assemblies with various organic bases, and as a model compound for investigating hydrogen-transfer motions in O—HÁ Á ÁN and N—HÁ Á ÁO hydrogen-bonded systems (Zaman et al, 2004; Seliger et al, 2009; Asaji et al 2010; Molcanov & Kojic-Prodic, 2010)
We have prepared two hydrogenbonded compounds of chloranilic acid–ethyleneurea (1/1) and chloranilic acid–hydantoin (1/2) in order to extend our study on D—HÁ Á ÁA hydrogen bonding (D = N, O, or C; A = N, O or Cl) in chloranilic acid–organic base systems (Gotoh & Ishida, 2017a,b, and references therein)
The O atom of ethyleneurea participates in two O—HÁ Á ÁO hydrogen bonds as an acceptor for two O—H groups of chloranilic acid (O2— H2Á Á ÁO5 and O4—H4Á Á ÁO5; Table 1)
Summary
Chloranilic acid, a dibasic acid with hydrogen-bond donor as well as acceptor groups, appears attractive as a template for generating tightly bound self-assemblies with various organic bases, and as a model compound for investigating hydrogen-transfer motions in O—HÁ Á ÁN and N—HÁ Á ÁO hydrogen-bonded systems (Zaman et al, 2004; Seliger et al, 2009; Asaji et al 2010; Molcanov & Kojic-Prodic, 2010). We have prepared two hydrogenbonded compounds of chloranilic acid–ethyleneurea (1/1) and chloranilic acid–hydantoin (1/2) in order to extend our study on D—HÁ Á ÁA hydrogen bonding (D = N, O, or C; A = N, O or Cl) in chloranilic acid–organic base systems (Gotoh & Ishida, 2017a,b, and references therein).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
