Related literature {#sec1}
==================

The 8-hydroxy­quinolinium cation has been isolated as a number of salts; for the 8-hydroxy­quinolinium chloride hydrate, see: Skakle *et al.* ( 2006[@bb6]).  For the crystal structure of 5-chloro-8-hydroxy­quinoline, see: Banerjee & Saha (1986[@bb1]). 

Experimental {#sec2}
============

 {#sec2.1}

### Crystal data {#sec2.1.1}

C~9~H~7~ClNO^+^·NO~3~ ^−^*M* *~r~* = 242.62Monoclinic,*a* = 7.4379 (3) Å*b* = 11.5518 (6) Å*c* = 11.2288 (5) Åβ = 95.831 (3)°*V* = 959.80 (8) Å^3^*Z* = 4Mo *K*α radiationμ = 0.40 mm^−1^*T* = 123 K0.20 × 0.05 × 0.05 mm

### Data collection {#sec2.1.2}

Bruker SMART APEX diffractometerAbsorption correction: multi-scan (*SADABS*; Sheldrick, 1996[@bb4]) *T* ~min~ = 0.925, *T* ~max~ = 0.9806472 measured reflections2196 independent reflections1574 reflections with *I* \> 2˘*I*)*R* ~int~ = 0.049

### Refinement {#sec2.1.3}

*R*\[*F* ^2^ \> 2σ(*F* ^2^)\] = 0.062*wR*(*F* ^2^) = 0.192*S* = 1.072196 reflections153 parameters2 restraintsH atoms treated by a mixture of independent and constrained refinementΔρ~max~ = 1.20 e Å^−3^Δρ~min~ = −0.34 e Å^−3^

 {#d5e406}

Data collection: *APEX2* (Bruker, 2008[@bb3]); cell refinement: *SAINT* (Bruker, 2008[@bb3]); data reduction: *SAINT*; program(s) used to solve structure: *SHELXS97* (Sheldrick, 2008[@bb5]); program(s) used to refine structure: *SHELXL97* (Sheldrick, 2008[@bb5]); molecular graphics: *X-SEED* (Barbour, 2001[@bb2]); software used to prepare material for publication: *publCIF* (Westrip, 2009[@bb7]). 

Supplementary Material
======================

Crystal structure: contains datablocks global, I. DOI: [10.1107/S160053680901993X/tk2465sup1.cif](http://dx.doi.org/10.1107/S160053680901993X/tk2465sup1.cif)

Structure factors: contains datablocks I. DOI: [10.1107/S160053680901993X/tk2465Isup2.hkl](http://dx.doi.org/10.1107/S160053680901993X/tk2465Isup2.hkl)

Additional supplementary materials: [crystallographic information](http://scripts.iucr.org/cgi-bin/sendsupfiles?tk2465&file=tk2465sup0.html&mime=text/html); [3D view](http://scripts.iucr.org/cgi-bin/sendcif?tk2465sup1&Qmime=cif); [checkCIF report](http://scripts.iucr.org/cgi-bin/paper?tk2465&checkcif=yes)

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: [TK2465](http://scripts.iucr.org/cgi-bin/sendsup?tk2465)). 

I thank the University of Malaya for supporting this study. 

Experimental {#experimental}
============

Zinc acetate (0.19 g, 1 mmol) and 5-chloro-8-hydroxyquinoline (0.36 g, 2 mmol) were loaded into a convection tube; the tube was filled with dry methanol and kept at 333 K. Yellow crystals were collected from the side-arm after several days. 

Refinement {#refinement}
==========

Carbon-bound H-atoms were placed in calculated positions (C--H 0.95 Å) and were included in the refinement in the riding model approximation with *U*(H) fixed at 1.2*U*(C).  The ammonium and hydroxy H-atoms were located in a difference Fourier map, and were refined with distance restraints of N--H = 0.88±0.01 Å and O--H = 0.84±0.01 Å; their isotropic temperature factors were refined. 

The final difference Fourier map had a large peak at about 1 Å from the Cl1 atom. 

Figures
=======

![ Thermal ellipsoid plot (Barbour, 2001) of a pair of hydrogen-bonded \[C9H7ClNO\]\[NO3\] ion pairs drawn at the 70% probability level.  Hydrogen atoms are drawn spheres of arbitrary radius and dashed lines denote hydrogen bonds.](e-65-o1450-fig1){#Fap1}

Crystal data {#tablewrapcrystaldatalong}
============

  -------------------------- ---------------------------------------
  C~9~H~7~ClNO^+^·NO~3~^−^   *F*(000) = 496
  *M~r~* = 242.62            *D*~x~ = 1.679 Mg m^−3^
  Monoclinic, *P*2~1~/*n*    Mo *K*α radiation, λ = 0.71073 Å
  Hall symbol: -P 2yn        Cell parameters from 1079 reflections
  *a* = 7.4379 (3) Å         θ = 2.5--26.4°
  *b* = 11.5518 (6) Å        µ = 0.40 mm^−1^
  *c* = 11.2288 (5) Å        *T* = 123 K
  β = 95.831 (3)°            Prism, yellow
  *V* = 959.80 (8) Å^3^      0.20 × 0.05 × 0.05 mm
  *Z* = 4                    
  -------------------------- ---------------------------------------

Data collection {#tablewrapdatacollectionlong}
===============

  --------------------------------------------------------------- -------------------------------------
  Bruker SMART APEX diffractometer                                2196 independent reflections
  Radiation source: fine-focus sealed tube                        1574 reflections with *I* \> 2˘*I*)
  graphite                                                        *R*~int~ = 0.049
  ω scans                                                         θ~max~ = 27.5°, θ~min~ = 2.5°
  Absorption correction: multi-scan (*SADABS*; Sheldrick, 1996)   *h* = −9→9
  *T*~min~ = 0.925, *T*~max~ = 0.980                              *k* = −15→12
  6472 measured reflections                                       *l* = −14→14
  --------------------------------------------------------------- -------------------------------------

Refinement {#tablewraprefinementdatalong}
==========

  ------------------------------------- -------------------------------------------------------------------------------------------------
  Refinement on *F*^2^                  Primary atom site location: structure-invariant direct methods
  Least-squares matrix: full            Secondary atom site location: difference Fourier map
  *R*\[*F*^2^ \> 2σ(*F*^2^)\] = 0.062   Hydrogen site location: inferred from neighbouring sites
  *wR*(*F*^2^) = 0.192                  H atoms treated by a mixture of independent and constrained refinement
  *S* = 1.07                            *w* = 1/\[σ^2^(*F*~o~^2^) + (0.1164*P*)^2^ + 0.1797*P*\] where *P* = (*F*~o~^2^ + 2*F*~c~^2^)/3
  2196 reflections                      (Δ/σ)~max~ = 0.001
  153 parameters                        Δρ~max~ = 1.20 e Å^−3^
  2 restraints                          Δρ~min~ = −0.34 e Å^−3^
  ------------------------------------- -------------------------------------------------------------------------------------------------

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å^2^) {#tablewrapcoords}
==================================================================================================

  ----- --------------- -------------- ------------- -------------------- --
        *x*             *y*            *z*           *U*~iso~\*/*U*~eq~   
  Cl1   −0.30656 (11)   0.30338 (8)    0.76985 (8)   0.0321 (3)           
  O1    0.3429 (3)      0.4706 (2)     0.5632 (2)    0.0279 (6)           
  H1O   0.350 (6)       0.5423 (11)    0.553 (4)     0.042 (12)\*         
  O2    0.5861 (3)      0.30211 (18)   0.4592 (2)    0.0261 (6)           
  O3    0.6434 (3)      0.12125 (19)   0.4947 (2)    0.0325 (6)           
  O4    0.8190 (3)      0.2201 (2)     0.3904 (2)    0.0286 (6)           
  N1    0.2829 (4)      0.2424 (2)     0.5774 (2)    0.0203 (6)           
  H1N   0.385 (3)       0.265 (4)      0.552 (3)     0.037 (11)\*         
  N2    0.6849 (4)      0.2125 (2)     0.4472 (2)    0.0220 (6)           
  C1    0.2635 (4)      0.1291 (3)     0.5806 (3)    0.0250 (7)           
  H1A   0.3516          0.0806         0.5504        0.030\*              
  C2    0.1155 (5)      0.0794 (3)     0.6278 (3)    0.0277 (7)           
  H2    0.1012          −0.0023        0.6295        0.033\*              
  C3    −0.0094 (4)     0.1513 (3)     0.6720 (3)    0.0265 (7)           
  H3    −0.1093         0.1185         0.7063        0.032\*              
  C4    0.0084 (4)      0.2727 (3)     0.6672 (3)    0.0213 (7)           
  C5    −0.1144 (4)     0.3518 (3)     0.7089 (3)    0.0254 (7)           
  C6    −0.0849 (5)     0.4687 (3)     0.7003 (3)    0.0325 (8)           
  H6    −0.1694         0.5213         0.7282        0.039\*              
  C7    0.0666 (5)      0.5118 (3)     0.6513 (3)    0.0297 (8)           
  H7    0.0832          0.5931         0.6460        0.036\*              
  C8    0.1920 (4)      0.4385 (3)     0.6108 (3)    0.0231 (7)           
  C9    0.1613 (4)      0.3178 (3)     0.6184 (3)    0.0204 (7)           
  ----- --------------- -------------- ------------- -------------------- --

Atomic displacement parameters (Å^2^) {#tablewrapadps}
=====================================

  ----- ------------- ------------- ------------- -------------- ------------- --------------
        *U*^11^       *U*^22^       *U*^33^       *U*^12^        *U*^13^       *U*^23^
  Cl1   0.0219 (5)    0.0405 (6)    0.0359 (5)    −0.0012 (3)    0.0128 (3)    −0.0003 (4)
  O1    0.0275 (13)   0.0173 (12)   0.0413 (14)   0.0001 (9)     0.0147 (10)   0.0025 (10)
  O2    0.0276 (13)   0.0138 (11)   0.0388 (13)   0.0032 (9)     0.0124 (10)   −0.0010 (9)
  O3    0.0337 (14)   0.0145 (11)   0.0513 (16)   −0.0003 (9)    0.0135 (12)   0.0044 (10)
  O4    0.0270 (13)   0.0265 (13)   0.0342 (13)   0.0027 (9)     0.0121 (10)   −0.0009 (10)
  N1    0.0173 (14)   0.0205 (13)   0.0235 (14)   0.0010 (10)    0.0046 (11)   0.0003 (10)
  N2    0.0214 (14)   0.0175 (13)   0.0274 (14)   0.0005 (10)    0.0038 (11)   −0.0025 (10)
  C1    0.0241 (17)   0.0199 (16)   0.0320 (18)   0.0020 (12)    0.0073 (13)   −0.0003 (13)
  C2    0.0278 (17)   0.0205 (16)   0.0356 (18)   −0.0003 (13)   0.0066 (14)   0.0058 (14)
  C3    0.0227 (17)   0.0272 (17)   0.0300 (17)   −0.0079 (13)   0.0043 (13)   0.0027 (13)
  C4    0.0208 (16)   0.0253 (16)   0.0180 (15)   −0.0034 (12)   0.0034 (12)   0.0000 (12)
  C5    0.0182 (16)   0.0337 (19)   0.0252 (16)   −0.0003 (13)   0.0074 (12)   0.0025 (13)
  C6    0.0271 (18)   0.0279 (18)   0.045 (2)     0.0074 (14)    0.0137 (15)   −0.0051 (15)
  C7    0.0291 (19)   0.0210 (17)   0.0405 (19)   0.0021 (13)    0.0111 (15)   −0.0024 (14)
  C8    0.0240 (16)   0.0201 (16)   0.0258 (16)   −0.0012 (12)   0.0058 (12)   0.0006 (12)
  C9    0.0239 (17)   0.0171 (15)   0.0203 (15)   0.0021 (12)    0.0021 (12)   0.0009 (11)
  ----- ------------- ------------- ------------- -------------- ------------- --------------

Geometric parameters (Å, °) {#tablewrapgeomlong}
===========================

  -------------------- ------------ ------------------- ------------
  Cl1---C5             1.739 (3)    C2---H2             0.9500
  O1---C8              1.343 (4)    C3---C4             1.410 (5)
  O1---H1O             0.84 (1)     C3---H3             0.9500
  O2---N2              1.285 (3)    C4---C5             1.405 (4)
  O3---N2              1.234 (3)    C4---C9             1.411 (4)
  O4---N2              1.240 (4)    C5---C6             1.374 (5)
  N1---C1              1.318 (4)    C6---C7             1.395 (5)
  N1---C9              1.368 (4)    C6---H6             0.9500
  N1---H1N             0.88 (1)     C7---C8             1.371 (4)
  C1---C2              1.393 (5)    C7---H7             0.9500
  C1---H1A             0.9500       C8---C9             1.417 (4)
  C2---C3              1.375 (5)                        
                                                        
  C8---O1---H1O        113 (3)      C5---C4---C3        124.6 (3)
  C1---N1---C9         123.0 (3)    C9---C4---C3        117.7 (3)
  C1---N1---H1N        114 (3)      C6---C5---C4        120.1 (3)
  C9---N1---H1N        123 (3)      C6---C5---Cl1       119.2 (3)
  O3---N2---O4         122.1 (3)    C4---C5---Cl1       120.7 (3)
  O3---N2---O2         118.2 (3)    C5---C6---C7        121.3 (3)
  O4---N2---O2         119.7 (3)    C5---C6---H6        119.3
  N1---C1---C2         120.8 (3)    C7---C6---H6        119.3
  N1---C1---H1A        119.6        C8---C7---C6        120.9 (3)
  C2---C1---H1A        119.6        C8---C7---H7        119.5
  C3---C2---C1         118.5 (3)    C6---C7---H7        119.5
  C3---C2---H2         120.7        O1---C8---C7        125.8 (3)
  C1---C2---H2         120.7        O1---C8---C9        116.3 (3)
  C2---C3---C4         121.2 (3)    C7---C8---C9        118.0 (3)
  C2---C3---H3         119.4        N1---C9---C4        118.8 (3)
  C4---C3---H3         119.4        N1---C9---C8        119.3 (3)
  C5---C4---C9         117.8 (3)    C4---C9---C8        121.9 (3)
                                                        
  C9---N1---C1---C2    −0.5 (5)     C6---C7---C8---O1   −179.4 (3)
  N1---C1---C2---C3    −0.5 (5)     C6---C7---C8---C9   1.0 (5)
  C1---C2---C3---C4    1.6 (5)      C1---N1---C9---C4   0.5 (4)
  C2---C3---C4---C5    179.2 (3)    C1---N1---C9---C8   −179.6 (3)
  C2---C3---C4---C9    −1.7 (5)     C5---C4---C9---N1   179.8 (3)
  C9---C4---C5---C6    0.8 (5)      C3---C4---C9---N1   0.6 (4)
  C3---C4---C5---C6    179.9 (3)    C5---C4---C9---C8   −0.2 (4)
  C9---C4---C5---Cl1   179.8 (2)    C3---C4---C9---C8   −179.4 (3)
  C3---C4---C5---Cl1   −1.1 (5)     O1---C8---C9---N1   −0.4 (4)
  C4---C5---C6---C7    −0.6 (5)     C7---C8---C9---N1   179.3 (3)
  Cl1---C5---C6---C7   −179.5 (3)   O1---C8---C9---C4   179.6 (3)
  C5---C6---C7---C8    −0.4 (6)     C7---C8---C9---C4   −0.7 (5)
  -------------------- ------------ ------------------- ------------

Hydrogen-bond geometry (Å, °) {#tablewraphbondslong}
=============================

  ------------------ ---------- ---------- ----------- ---------------
  *D*---H···*A*      *D*---H    H···*A*    *D*···*A*   *D*---H···*A*
  O1---H1o···O2^i^   0.84 (1)   1.87 (1)   2.695 (3)   169 (4)
  N1---H1n···O2      0.88 (1)   1.95 (1)   2.816 (3)   167 (4)
  ------------------ ---------- ---------- ----------- ---------------

Symmetry codes: (i) −*x*+1, −*y*+1, −*z*+1. 

###### Hydrogen-bond geometry (Å, °)

  *D*---H⋯*A*      *D*---H    H⋯*A*      *D*⋯*A*     *D*---H⋯*A*
  ---------------- ---------- ---------- ----------- -------------
  O1---H1o⋯O2^i^   0.84 (1)   1.87 (1)   2.695 (3)   169 (4)
  N1---H1n⋯O2      0.88 (1)   1.95 (1)   2.816 (3)   167 (4)

Symmetry code: (i) .