PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2010 February 1; 66(Pt 2): m109–m110.
Published online 2010 January 9. doi:  10.1107/S1600536809054439
PMCID: PMC2979955

Diguanidinium bis­(μ-2-hydroxy­propane-1,2,3-tricarboxyl­ato)bis­[diaqua­zincate(II)] dihydrate

Abstract

The asymmetric unit of the title compound, (CH6N3)2[Zn2(C6H5O7)2(H2O)2]·2H2O, contains one-half of a centrosymmetric dizinc(II) complex anion, one guanidinium cation and one water mol­ecule. Each ZnII ion is hexa­coordinated by two citrate anions, one in a bidentate fashion and the second monodentate, and two water mol­ecules in a distorted octa­hedral geometry. Intra­molecular O—H(...)O hydrogen bonds add further stability to the mol­ecular structure. In the crystal structure, mol­ecules are linked into a three-dimensional framework by inter­molecular N—H(...)O, O—H(...)O and C—H(...)O hydrogen bonds.

Related literature

For general background to guanidine and citric acid, see: Raczyńska et al. (2003 [triangle]); Yamada et al. (2009 [triangle]); Sigman et al. (1993 [triangle]); Schuck (1934 [triangle]); Sherman et al. (1936 [triangle]). For applications of citric acid in industry and materials science, see: Blair et al. (1991 [triangle]); Jiang et al. (2007 [triangle]). For related guanidinium structures, see: Al-Dajani et al. (2009a [triangle],b [triangle]). For hydrogen-bond motifs, see: Bernstein et al. (1995 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0m109-scheme1.jpg

Experimental

Crystal data

  • (CH6N3)2[Zn2(C6H5O7)2(H2O)2]·2H2O
  • M r = 737.21
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0m109-efi3.jpg
  • a = 28.9405 (4) Å
  • b = 8.5708 (1) Å
  • c = 11.3395 (2) Å
  • β = 95.249 (1)°
  • V = 2800.89 (7) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 1.81 mm−1
  • T = 296 K
  • 0.32 × 0.30 × 0.18 mm

Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.593, T max = 0.734
  • 32332 measured reflections
  • 7693 independent reflections
  • 5495 reflections with I > 2σ(I)
  • R int = 0.026

Refinement

  • R[F 2 > 2σ(F 2)] = 0.031
  • wR(F 2) = 0.084
  • S = 1.05
  • 7693 reflections
  • 190 parameters
  • H-atom parameters constrained
  • Δρmax = 0.45 e Å−3
  • Δρmin = −0.29 e Å−3

Data collection: APEX2 (Bruker, 2005 [triangle]); cell refinement: SAINT (Bruker, 2005 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809054439/sj2710sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809054439/sj2710Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

HHA gratefully acknowledges funding from Universiti Sains Malaysia (USM) under the University Research Grant (No. 1001/PKIMIA/811142). HKF thanks USM for the Research University Golden Goose Grant (No. 1001/PFIZIK/811012). CSY thanks USM for the award of a USM Fellowship.

supplementary crystallographic information

Comment

Citric acid or 2-hydroxy-1,2,3-propanetricarboxylic acid contains three carboxyl groups. It is found in the literature that an organism has the ability to synthesize citric acid. (Schuck, 1934; Sherman et al., 1936). Citric acid has many applications including use in the manufacture of detergents, shampoos, cosmetics and in chemical cleaning (Blair et al., 1991). It can also be used for the preparation of the catalyst LaNiO3 for the preparation of carbon nanotubes (Jiang et al., 2007).

Guanidine can be formed by the oxidation of guanine as a final product of the protein metabolism (Raczyńska et al., 2003; Yamada et al., 2009; Sigman et al., 1993).

The asymmetric unit of title compound contains one half of a dizinc(II) complex anion, one guanidinium cation and one water solvent molecule (Fig. 1). The anion lies across a crystallographic inversion center, the other half is symmetry generated [symmetry code: 1/2 - x, 1/2 - y, 1 - z]. The Zn1 and Zn2 ions are coordinated to four O atoms from two citrate anions and two water molecules to form a distorted octahedral geometry. Two citric acid molecules are deprotonated and two guanidine molecules protonated to yield the cation and anion. The geometrical parameters of the guanidinium cations agree with those previously reported (Al-Dajani et al., 2009a,b). An intramolecular O3—H1O3···O6 hydrogen bond generates an S(6) ring motif (Bernstein et al., 1995).

In crystal structure (Fig. 2), the ZnII complex anion and water molecules are linked into sheets parallel to the bc plane via intermoleculer O1W—H1W1···O2, O1W—H2W1···O5, O2W—H1W2···O1, O2W—H2W2···O7, O3W—H1W3···O2, O3W—H2W3···O7 and C5—H5B···O3W hydrogen bonds. The guanidinium cations are linked these sheets generating a three-dimensional framework through N—H···O hydrogen bonds (Table 1).

Experimental

Citric acid (anhydrous) (0.02 mol, 3.85 g) was dissolved in THF in a flat bottom flask with magnetic stirrer. In a separating funnel, guanidine carbonate (0.005 mol, 0.9 g), 99% [H2NC(NH)NH2].2H2CO3 was dissolved in THF. The guanidine solution was added in small portions to the citric acid with stirring. At room temperature, zinc chloride (ZnCl2) (0.02 mol, 2.75 g) was added also with stirring. The reaction mixture was refluxed for 30 min. After cooling the mixture to room temperature, it was left stirring overnight. The resulting colourless crystals were filtered, washed with methanol and dried at 353 K.

Refinement

N-bound and O-bound H atoms were located in a difference Fourier map and refined as riding on their parent atom, with Uiso(H) = 1.2, 1.5Ueq(N, O). The remaining H atoms were positioned geometrically [C–H = 0.97 Å and refined using a riding model, with Uiso(H) = 1.2Ueq(C)].

Figures

Fig. 1.
The molecular structure of the title compound with atom labels and 30% probability ellipsoids for non-H atoms. Atoms with suffix A are generated by the symmetry operation (1/2 - x, 1/2 - y, 1 - z).
Fig. 2.
The crystal packing of title compound, viewed down the c axis, showing the hydrogen-bonded (dashed lines) three-dimensional framework. Hydrogen atoms not involved in the hydrogen-bonding have been omitted for clarity.

Crystal data

(CH6N3)2[Zn2(C6H5O7)2(H2O)2]·2H2OF(000) = 1520
Mr = 737.21Dx = 1.748 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 9983 reflections
a = 28.9405 (4) Åθ = 2.5–34.8°
b = 8.5708 (1) ŵ = 1.81 mm1
c = 11.3395 (2) ÅT = 296 K
β = 95.249 (1)°Block, colourless
V = 2800.89 (7) Å30.32 × 0.30 × 0.18 mm
Z = 4

Data collection

Bruker SMART APEXII CCD area-detector diffractometer7693 independent reflections
Radiation source: fine-focus sealed tube5495 reflections with I > 2σ(I)
graphiteRint = 0.026
[var phi] and ω scansθmax = 38.3°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −48→50
Tmin = 0.593, Tmax = 0.734k = −14→12
32332 measured reflectionsl = −19→16

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.084H-atom parameters constrained
S = 1.05w = 1/[σ2(Fo2) + (0.0404P)2 + 0.5068P] where P = (Fo2 + 2Fc2)/3
7693 reflections(Δ/σ)max = 0.002
190 parametersΔρmax = 0.45 e Å3
0 restraintsΔρmin = −0.29 e Å3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
Zn10.322092 (4)0.394890 (14)0.631912 (11)0.02481 (4)
O10.33231 (4)0.37163 (9)0.45220 (8)0.03439 (19)
O20.36716 (3)0.20991 (10)0.33603 (8)0.03573 (18)
O30.31089 (3)0.15045 (9)0.60117 (7)0.02494 (14)
H1O30.28150.14280.56510.037*
O40.39328 (3)0.33281 (11)0.66307 (9)0.03675 (19)
O50.44700 (3)0.16069 (13)0.72462 (10)0.0474 (2)
O60.24882 (3)0.07623 (10)0.42434 (9)0.0365 (2)
O70.25557 (3)−0.16794 (10)0.36365 (10)0.0427 (2)
C10.34724 (4)0.23880 (12)0.42612 (9)0.02427 (18)
C20.34175 (3)0.10406 (10)0.51507 (9)0.02214 (16)
C30.38848 (4)0.06848 (13)0.58412 (10)0.0288 (2)
H3A0.3844−0.02210.63340.035*
H3B0.41010.03930.52750.035*
C40.41101 (4)0.19654 (14)0.66293 (10)0.0295 (2)
C50.32367 (4)−0.04392 (12)0.44989 (10)0.0273 (2)
H5A0.3410−0.05860.38140.033*
H5B0.3302−0.13250.50200.033*
C60.27248 (4)−0.04513 (12)0.40863 (10)0.02705 (19)
C70.45073 (5)0.64963 (16)0.50364 (12)0.0382 (3)
N10.45132 (5)0.61025 (16)0.61676 (12)0.0511 (3)
H1N10.46440.66410.67510.061*
H2N10.43930.51870.64240.061*
N20.47821 (5)0.76043 (17)0.47097 (13)0.0552 (3)
H1N20.47830.78880.39660.066*
H2N20.50000.79450.52350.066*
N30.42259 (5)0.57429 (17)0.42351 (13)0.0547 (3)
H1N30.42080.62090.35590.066*
H2N30.40200.51350.44540.066*
O1W0.46013 (4)0.85648 (15)0.82510 (11)0.0525 (3)
H1W10.43350.83730.83060.079*
H2W10.45930.94700.80200.079*
O2W0.31354 (4)0.38177 (10)0.80498 (8)0.0388 (2)
H1W20.31630.46100.84920.058*
H2W20.29750.32360.83210.058*
O3W0.33513 (3)0.63182 (9)0.63707 (8)0.03042 (16)
H1W30.34940.66610.70040.046*
H2W30.31060.65610.63280.046*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Zn10.02665 (6)0.02218 (6)0.02509 (7)0.00090 (4)−0.00047 (4)−0.00195 (4)
O10.0534 (5)0.0230 (3)0.0269 (4)0.0080 (3)0.0047 (4)0.0038 (3)
O20.0384 (4)0.0412 (4)0.0285 (4)0.0094 (4)0.0079 (3)0.0043 (3)
O30.0251 (3)0.0245 (3)0.0252 (3)−0.0002 (3)0.0025 (3)−0.0024 (3)
O40.0276 (4)0.0324 (4)0.0490 (5)−0.0006 (3)−0.0035 (3)−0.0064 (4)
O50.0344 (5)0.0509 (6)0.0527 (6)0.0026 (4)−0.0192 (4)−0.0009 (5)
O60.0275 (4)0.0277 (4)0.0521 (5)0.0073 (3)−0.0089 (4)−0.0145 (4)
O70.0306 (4)0.0291 (4)0.0666 (7)0.0027 (3)−0.0057 (4)−0.0205 (4)
C10.0243 (4)0.0252 (4)0.0226 (4)0.0018 (3)−0.0016 (3)0.0015 (3)
C20.0221 (4)0.0207 (4)0.0231 (4)0.0036 (3)−0.0010 (3)−0.0007 (3)
C30.0259 (5)0.0282 (4)0.0307 (5)0.0052 (4)−0.0055 (4)0.0016 (4)
C40.0226 (4)0.0355 (5)0.0298 (5)−0.0006 (4)−0.0011 (4)0.0022 (4)
C50.0246 (4)0.0220 (4)0.0345 (5)0.0042 (3)−0.0010 (4)−0.0040 (4)
C60.0262 (4)0.0242 (4)0.0302 (5)0.0032 (4)−0.0005 (4)−0.0051 (4)
C70.0341 (6)0.0395 (6)0.0399 (7)−0.0022 (5)−0.0028 (5)0.0025 (5)
N10.0547 (8)0.0579 (8)0.0388 (7)−0.0176 (6)−0.0058 (6)0.0040 (5)
N20.0531 (7)0.0576 (8)0.0534 (8)−0.0190 (6)−0.0043 (6)0.0139 (6)
N30.0586 (8)0.0594 (8)0.0436 (7)−0.0202 (7)−0.0091 (6)0.0033 (6)
O1W0.0347 (5)0.0645 (7)0.0585 (7)0.0026 (5)0.0055 (5)0.0105 (6)
O2W0.0571 (6)0.0320 (4)0.0284 (4)−0.0179 (4)0.0093 (4)−0.0048 (3)
O3W0.0321 (4)0.0257 (3)0.0332 (4)−0.0030 (3)0.0009 (3)−0.0003 (3)

Geometric parameters (Å, °)

Zn1—O2W2.0036 (9)C3—H3B0.9700
Zn1—O3W2.0653 (8)C5—C61.5123 (15)
Zn1—O12.0953 (9)C5—H5A0.9700
Zn1—O6i2.1071 (9)C5—H5B0.9700
Zn1—O42.1259 (9)C7—N21.3135 (18)
Zn1—O32.1436 (8)C7—N11.3250 (19)
O1—C11.2624 (12)C7—N31.3305 (18)
O2—C11.2430 (13)N1—H1N10.8653
O3—C21.4382 (12)N1—H2N10.9161
O3—H1O30.9125N2—H1N20.8782
O4—C41.2757 (15)N2—H2N20.8767
O5—C41.2389 (14)N3—H1N30.8616
O6—C61.2669 (12)N3—H2N30.8455
O6—Zn1i2.1071 (9)O1W—H1W10.7969
O7—C61.2498 (13)O1W—H2W10.8189
C1—C21.5510 (14)O2W—H1W20.8432
C2—C31.5302 (14)O2W—H2W20.7641
C2—C51.5355 (14)O3W—H1W30.8481
C3—C41.5237 (16)O3W—H2W30.7377
C3—H3A0.9700
O2W—Zn1—O3W93.79 (3)C2—C3—H3B107.8
O2W—Zn1—O1171.26 (3)H3A—C3—H3B107.2
O3W—Zn1—O194.55 (3)O5—C4—O4122.94 (11)
O2W—Zn1—O6i95.68 (4)O5—C4—C3116.42 (11)
O3W—Zn1—O6i93.63 (3)O4—C4—C3120.64 (9)
O1—Zn1—O6i86.38 (4)C6—C5—C2115.82 (8)
O2W—Zn1—O491.59 (4)C6—C5—H5A108.3
O3W—Zn1—O494.00 (4)C2—C5—H5A108.3
O1—Zn1—O485.24 (4)C6—C5—H5B108.3
O6i—Zn1—O4169.08 (3)C2—C5—H5B108.3
O2W—Zn1—O394.25 (3)H5A—C5—H5B107.4
O3W—Zn1—O3171.92 (3)O7—C6—O6123.51 (10)
O1—Zn1—O377.38 (3)O7—C6—C5117.91 (9)
O6i—Zn1—O386.39 (3)O6—C6—C5118.54 (9)
O4—Zn1—O384.96 (3)N2—C7—N1120.18 (13)
C1—O1—Zn1113.29 (7)N2—C7—N3120.45 (14)
C2—O3—Zn1106.65 (6)N1—C7—N3119.36 (13)
C2—O3—H1O3106.7C7—N1—H1N1124.8
Zn1—O3—H1O3105.3C7—N1—H2N1123.6
C4—O4—Zn1127.79 (7)H1N1—N1—H2N1111.5
C6—O6—Zn1i125.31 (7)C7—N2—H1N2121.7
O2—C1—O1124.51 (10)C7—N2—H2N2117.8
O2—C1—C2117.97 (9)H1N2—N2—H2N2119.7
O1—C1—C2117.48 (9)C7—N3—H1N3111.4
O3—C2—C3106.41 (8)C7—N3—H2N3120.1
O3—C2—C5110.47 (8)H1N3—N3—H2N3124.1
C3—C2—C5109.15 (8)H1W1—O1W—H2W1102.7
O3—C2—C1110.03 (7)Zn1—O2W—H1W2121.5
C3—C2—C1110.05 (9)Zn1—O2W—H2W2124.3
C5—C2—C1110.64 (9)H1W2—O2W—H2W2108.4
C4—C3—C2117.86 (9)Zn1—O3W—H1W3116.0
C4—C3—H3A107.8Zn1—O3W—H2W395.9
C2—C3—H3A107.8H1W3—O3W—H2W3110.5
C4—C3—H3B107.8
O3W—Zn1—O1—C1150.43 (8)O1—C1—C2—O312.55 (13)
O6i—Zn1—O1—C1−116.20 (9)O2—C1—C2—C373.57 (12)
O4—Zn1—O1—C156.79 (8)O1—C1—C2—C3−104.39 (11)
O3—Zn1—O1—C1−29.10 (8)O2—C1—C2—C5−47.13 (12)
O2W—Zn1—O3—C2−143.52 (7)O1—C1—C2—C5134.91 (10)
O1—Zn1—O3—C233.95 (6)O3—C2—C3—C4−56.32 (12)
O6i—Zn1—O3—C2121.05 (6)C5—C2—C3—C4−175.54 (10)
O4—Zn1—O3—C2−52.29 (6)C1—C2—C3—C462.86 (12)
O2W—Zn1—O4—C491.34 (10)Zn1—O4—C4—O5−150.02 (10)
O3W—Zn1—O4—C4−174.75 (10)Zn1—O4—C4—C330.55 (16)
O1—Zn1—O4—C4−80.50 (10)C2—C3—C4—O5174.68 (11)
O6i—Zn1—O4—C4−40.5 (3)C2—C3—C4—O4−5.86 (17)
O3—Zn1—O4—C4−2.78 (10)O3—C2—C5—C645.40 (12)
Zn1—O1—C1—O2−160.08 (9)C3—C2—C5—C6162.07 (10)
Zn1—O1—C1—C217.74 (12)C1—C2—C5—C6−76.69 (12)
Zn1—O3—C2—C384.83 (8)Zn1i—O6—C6—O7−4.75 (18)
Zn1—O3—C2—C5−156.82 (6)Zn1i—O6—C6—C5177.29 (8)
Zn1—O3—C2—C1−34.36 (9)C2—C5—C6—O7−174.40 (11)
O2—C1—C2—O3−169.49 (9)C2—C5—C6—O63.68 (16)

Symmetry codes: (i) −x+1/2, −y+1/2, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O3—H1O3···O60.911.872.6445 (13)142
N1—H1N1···O1W0.862.383.1607 (19)150
N1—H2N1···O40.922.102.9855 (17)161
N2—H1N2···O5ii0.882.122.9351 (18)154
N2—H2N2···O1Wiii0.882.052.9077 (19)166
N3—H1N3···O4ii0.862.293.1011 (18)156
N3—H1N3···O5ii0.862.553.3221 (18)150
N3—H2N3···O10.852.363.1788 (18)162
O1W—H1W1···O2iv0.801.972.7640 (15)177
O1W—H2W1···O5v0.822.052.8568 (17)170
O2W—H1W2···O1iv0.841.882.7172 (12)171
O2W—H2W2···O7vi0.761.862.6116 (13)167
O3W—H1W3···O2iv0.851.902.7215 (12)163
O3W—H2W3···O7i0.741.922.6424 (12)166
C5—H5B···O3Wvii0.972.533.4943 (13)172

Symmetry codes: (ii) x, −y+1, z−1/2; (iii) −x+1, y, −z+3/2; (iv) x, −y+1, z+1/2; (v) x, y+1, z; (vi) x, −y, z+1/2; (i) −x+1/2, −y+1/2, −z+1; (vii) x, y−1, z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ2710).

References

  • Al-Dajani, M. T. M., Abdallah, H. H., Mohamed, N., Goh, J. H. & Fun, H.-K. (2009a). Acta Cryst. E65, o2508–o2509. [PMC free article] [PubMed]
  • Al-Dajani, M. T. M., Abdallah, H. H., Mohamed, N., Yeap, C. S. & Fun, H.-K. (2009b). Acta Cryst. E65, m1540–m1541. [PMC free article] [PubMed]
  • Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl.34, 1555–1573.
  • Blair, G., Staal, P., Haarmann & Reimer Corporation (1991). Citric Acid, in Encyclopedia of Chemical Technology, edited by J. I. Kroschwitz & M. Howe-Grant, pp. 354–380. New York: John Wiley & Sons Inc.
  • Bruker (2005). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Jiang, Q., Song, L. J., Zhao, Y., Lu, X. Y., Zhu, T. Y., Qian, L., Ren, X. M. & Cai, Y. D. (2007). Mater. Lett.61, 2749–2752.
  • Raczyńska, E. D., Cyrański, M. K., Gutowski, M., Rak, J., Gal, J.-F., Maria, P.-C., Darowska, M. & Duczmal, K. (2003). J. Phys. Org. Chem.16, 91–106.
  • Schuck, C. (1934). J. Nutrit.7, 679–684.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Sherman, C. C., Mendel, L. B. & Smith, A. H. (1936). J. Biol. Chem.113, 247–254.
  • Sigman, D. S., Mazumder, A. & Perrin, D. M. (1993). Chem. Rev.93, 2295–2316.
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]
  • Yamada, T., Liu, X., Englert, U., Darowska, M. & Duczmal, K. (2009). Chem. Eur. J.15, 5651–5655. [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography