Acta Crystallographica Section C

Structural Chemistry

Volume 70, Part 3 (March 2014)

organic compounds

ky3047 scheme

Acta Cryst. (2014). C70, 315-319    [ doi:10.1107/S2053229614002459 ]

Hydrogen-bonded two- and three-dimensional polymeric structures in the ammonium salts of 3,5-di­nitro­benzoic acid, 4-nitro­benzoic acid and 2,4-di­chloro­benzoic acid

G. Smith

Abstract: The structures of ammonium 3,5-di­nitro­benzoate, NH4+·C7H3N2O6-, (I), ammonium 4-nitro­benzoate dihydrate, NH4+·C7H4NO4-·2H2O, (II), and ammonium 2,4-di­chloro­benzoate hemihydrate, NH4+·C7H3Cl2O2-·0.5H2O, (III), have been determined and their hydrogen-bonded structures are described. All three salts form hydrogen-bonded polymeric structures, viz. three-dimensional in (I) and two-dimensional in (II) and (III). With (I), a primary cation-anion cyclic association is formed [graph set R43(10)] through N-H...O hydrogen bonds, involving a carboxyl­ate group with both O atoms contributing to the hydrogen bonds (denoted O,O'-carboxyl­ate) on one side and a carboxyl­ate group with one O atom involved in two hydrogen bonds (denoted O-carboxyl­ate) on the other. Structure extension involves N-H...O hydrogen bonds to both carboxyl­ate and nitro O-atom acceptors. With structure (II), the primary inter-species inter­actions and structure extension into layers lying parallel to (001) are through conjoined cyclic hydrogen-bonding motifs, viz. R43(10) (one cation, an O,O'-carboxyl­ate group and two water mol­ecules) and centrosymmetric R42(8) (two cations and two water mol­ecules). The structure of (III) also has conjoined R43(10) and centrosymmetric R42(8) motifs in the layered structure but these differ in that the first motif involves one cation, an O,O'-carboxyl­ate group, an O-carboxyl­ate group and one water mol­ecule, and the second motif involves two cations and two O-carboxyl­ate groups. The layers lie parallel to (100). The structures of salt hydrates (II) and (III), displaying two-dimensional layered arrays through conjoined hydrogen-bonded nets, provide further illustration of a previously indicated trend among ammonium salts of carb­oxy­lic acids, but the anhydrous three-dimensional structure of (I) is inconsistent with that trend.

CCDC references: 984839, 984840 and 984841

Formula: NH4+ salts of C7H3N2O6-, C7H4NO4-·2H2O and C7H3Cl2O2-·0.5H2O

Keywords: crystal structure; hydrogen bonding; ammonium salts; polymeric hydrogen-bonded systems; 3,5-di­nitro­benzoate; 4-nitro­benzoate; 2,4-di­chloro­benzoate.

cmldisplay filedownload file

Chemical Markup Language (CML) file (3.9 kbytes)
[ doi:10.1107/S2053229614002459/ky3047Isup5.cml ]
Supplementary material

cmldisplay filedownload file

Chemical Markup Language (CML) file (4.0 kbytes)
[ doi:10.1107/S2053229614002459/ky3047IIsup6.cml ]
Supplementary material

cmldisplay filedownload file

Chemical Markup Language (CML) file (3.4 kbytes)
[ doi:10.1107/S2053229614002459/ky3047IIIsup7.cml ]
Supplementary material


To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.

 bibliographic record in  format