inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Tetra­ammineplatinum(II) dichloride ammonia tetra­solvate

aInstitut für Anorganische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
*Correspondence e-mail: nikolaus.korber@chemie.uni-regensburg.de

(Received 25 April 2014; accepted 27 May 2014; online 7 June 2014)

The title compound, [Pt(NH3)4]Cl2·4NH3, was crystallized in liquid ammonia from the salt PtCl2. The platinum cation is coordinated by four ammonia mol­ecules, forming a square-planar complex. The chloride anions are surrounded by nine ammonia mol­ecules, either bound within the platinum complex or solvent mol­ecules. The solvent ammonia mol­ecules are packed in such a way that an extended network of N—H⋯N and N—H⋯Cl hydrogen bonds is formed. The structure is isotypic with [Pd(NH3)4]Cl2·4NH3 [Grassl & Korber (2014). Acta Cryst. E70, i32].

Related literature

For weak inter­molecular inter­actions such as hydrogen bonds and their application in crystal engineering, see: Desiraju (2002[Desiraju, G. R. (2002). Acc. Chem. Res. 35, 565-573.], 2007[Desiraju, G. R. (2007). Angew. Chem. Int. Ed. 46, 8342-8356.]); Steiner (2002[Steiner, T. (2002). Angew. Chem., 114, 50-80.]). For the structure of Magnus salt and tetra­amminplatinous salts, see: Atoji et al. (1957[Atoji, M., Richardson, J. W. & Rundle, R. E. (1957). J. Am. Chem. Soc. 79, 3017-3020.]); Cox (1932[Cox, E. G. (1932). J. Chem. Soc. 6, 1912-1920.]); Smolentsev et al. (2010[Smolentsev, A. I., Gubanov, A. I., Zadesenets, A. V., Plyusnin, P. E., Baidina, I. A. & Korenev, S. V. (2010). J. Struct. Chem. 51, 709-713.]). The Pd analogue is described by Grassl & Korber (2014[Grassl, T. & Korber, N. (2014). Acta Cryst. E70, i32.]).

Experimental

Crystal data
  • [Pt(NH3)4]Cl2·4NH3

  • Mr = 402.25

  • Monoclinic, P 21 /n

  • a = 7.6641 (2) Å

  • b = 10.1601 (3) Å

  • c = 8.7797 (2) Å

  • β = 100.975 (3)°

  • V = 671.15 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 10.83 mm−1

  • T = 123 K

  • 0.2 × 0.1 × 0.1 mm

Data collection
  • Agilent Xcalibur (Ruby, Gemini ultra) diffractometer

  • Absorption correction: analytical [CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.]), using a multi-faceted crystal model based on expressions derived by Clark & Reid (1995[Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897.])] Tmin = 0.162, Tmax = 0.462

  • 14167 measured reflections

  • 1368 independent reflections

  • 1276 reflections with I > 2σ(I)

  • Rint = 0.022

Refinement
  • R[F2 > 2σ(F2)] = 0.009

  • wR(F2) = 0.021

  • S = 1.12

  • 1368 reflections

  • 100 parameters

  • All H-atom parameters refined

  • Δρmax = 0.44 e Å−3

  • Δρmin = −0.29 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2A⋯Cl1 0.85 (2) 2.62 (2) 3.4437 (16) 162.8 (19)
N2—H2B⋯Cl1i 0.85 (2) 2.52 (2) 3.3594 (17) 169.0 (19)
N1—H1A⋯Cl1i 0.91 (2) 2.42 (2) 3.3155 (17) 170.2 (17)
N4—H4A⋯Cl1ii 0.89 (3) 2.81 (3) 3.6330 (19) 154 (2)
N1—H1B⋯Cl1ii 0.90 (3) 2.45 (3) 3.3440 (17) 173 (2)
N2—H2C⋯N4iii 0.86 (2) 2.16 (2) 3.020 (2) 178 (2)
N3—H3A⋯Cl1 0.84 (3) 2.75 (3) 3.583 (2) 171 (2)
N4—H4B⋯Cl1 0.93 (4) 2.64 (4) 3.544 (2) 166 (3)
N4—H4C⋯Cl1iv 0.82 (5) 2.82 (5) 3.608 (2) 163 (4)
N1—H1C⋯N3v 0.89 (3) 2.08 (3) 2.970 (2) 178.1 (19)
N3—H3B⋯Cl1vi 0.83 (3) 2.80 (3) 3.616 (2) 168 (3)
Symmetry codes: (i) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]; (ii) -x+1, -y+1, -z+1; (iii) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (iv) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (v) -x+2, -y+1, -z+1; (vi) -x+1, -y+1, -z.

Data collection: CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: OLEX2.solve (Bourhis et al., 2014[Bourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2014). In preparation.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg & Putz, 2012[Brandenburg, K. & Putz, H. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]).

Supporting information


Comment top

The crystal structure of the title compound was determined in the course of investigations regarding the reactivity of carbohydrates towards metal cations in liquid ammonia.

In the crystal structure the platinum cation forms a homoleptic ammine complex with a square-planar coordination geometry. The Pt—N bond lengths are 2.0471 (16) Å and 2.0519 (15) Å, respectively. This is in good accordance with the bond lengths given by Smolentsev et al. (2010). The angles N—Pt—N are 89.24 (6)° and 90.76 (6)°, and within the complex, ammonia ligands opposite to each other have staggered hydrogen atom positions (Fig 1).

The chloride anion shows nine direct contacts to hydrogen atoms of ammonia molecules either bound in the complex or to solvate molecules, forming a network of hydrogen bonds (Fig. 2 and Fig. 3). The N—H···Cl bond angles range between 154 (2)° and 173 (2)° whereas N—H···Cl bond lengths have values between 2.42 (2) Å and 2.82 (5) Å. The two occurring N—H···N bridges are nearly linear, with bond angles of 178 (2)° and 178.1 (19)° and bond lengths considerably less than the sum of the van der Waals radii of nitrogen and hydrogen [2.16 (2) Å and 2.08 (3) Å]. This gives strong evidence that the arrangement of the overall structure is significantly driven by the energy contribution of N—H···N and N—H···Cl hydrogen bonds.

Related literature top

For weak intermolecular interactions such as hydrogen bonds and their application in crystal engeneering, see: Desiraju (2002, 2007); Steiner (2002). For the structure of Magnus salt and tetraamminplatinous salts, see: Atoji et al. (1957); Cox (1932); Smolentsev et al. (2010). The Pd analogue is described by Graßl & Korber (2014).

Experimental top

0.25 g (1.0 mmol) PtCl2 and 0.21 g (1.00 mmol) N-acetylglucosamine were placed under argon atmosphere in a reaction vessel and 40 ml of dry liquid ammonia were condensed. The mixture was stored at 237 K for one week to ensure that all substances were completely dissolved. The flask was then stored at 161 K for five months. After that period, clear colorless crystals of the title compound were found at the bottom of the flask.

Refinement top

The crystal structure does not show any features where special refinement methods have to be applied. All hydrogen atoms could be located in difference map and both bond angle/bond length and isotropic displacement parameters were refined.

Structure description top

The crystal structure of the title compound was determined in the course of investigations regarding the reactivity of carbohydrates towards metal cations in liquid ammonia.

In the crystal structure the platinum cation forms a homoleptic ammine complex with a square-planar coordination geometry. The Pt—N bond lengths are 2.0471 (16) Å and 2.0519 (15) Å, respectively. This is in good accordance with the bond lengths given by Smolentsev et al. (2010). The angles N—Pt—N are 89.24 (6)° and 90.76 (6)°, and within the complex, ammonia ligands opposite to each other have staggered hydrogen atom positions (Fig 1).

The chloride anion shows nine direct contacts to hydrogen atoms of ammonia molecules either bound in the complex or to solvate molecules, forming a network of hydrogen bonds (Fig. 2 and Fig. 3). The N—H···Cl bond angles range between 154 (2)° and 173 (2)° whereas N—H···Cl bond lengths have values between 2.42 (2) Å and 2.82 (5) Å. The two occurring N—H···N bridges are nearly linear, with bond angles of 178 (2)° and 178.1 (19)° and bond lengths considerably less than the sum of the van der Waals radii of nitrogen and hydrogen [2.16 (2) Å and 2.08 (3) Å]. This gives strong evidence that the arrangement of the overall structure is significantly driven by the energy contribution of N—H···N and N—H···Cl hydrogen bonds.

For weak intermolecular interactions such as hydrogen bonds and their application in crystal engeneering, see: Desiraju (2002, 2007); Steiner (2002). For the structure of Magnus salt and tetraamminplatinous salts, see: Atoji et al. (1957); Cox (1932); Smolentsev et al. (2010). The Pd analogue is described by Graßl & Korber (2014).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: olex2.solve (Bourhis et al., 2014); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2012); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Figures top
[Figure 1] Fig. 1. : Crystal structure of the title compound with labeling and displacement ellipsoids drawn at the 50% probability level. Symmetry code: (i) 2 - x, 1 - y, 1 - z.
[Figure 2] Fig. 2. : The chloride anion is shown with its surrounding molecules. The predominant bond type is hydrogen bonding. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 3] Fig. 3. : Extended network of hydrogen bonds in the crystal structure. The solvent ammonia molecules are oriented to optimize the hydrogen bond geometry. Displacement ellipsoids are drawn at the 50% probability level.
Tetraammineplatinum(II) dichloride ammonia tetrasolvate top
Crystal data top
[Pt(NH3)4]Cl2·4NH3F(000) = 384
Mr = 402.25Dx = 1.991 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 7.6641 (2) ÅCell parameters from 9522 reflections
b = 10.1601 (3) Åθ = 3.1–30.6°
c = 8.7797 (2) ŵ = 10.83 mm1
β = 100.975 (3)°T = 123 K
V = 671.15 (3) Å3Block, clear light colourless
Z = 20.2 × 0.1 × 0.1 mm
Data collection top
Agilent Xcalibur (Ruby, Gemini ultra)
diffractometer
1368 independent reflections
Radiation source: fine-focus sealed tube1276 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
phi and ω scansθmax = 26.4°, θmin = 3.1°
Absorption correction: analytical
[CrysAlis PRO (Agilent, 2012), using a multi-faceted crystal model based on expressions derived by Clark & Reid (1995)]
h = 99
Tmin = 0.162, Tmax = 0.462k = 1212
14167 measured reflectionsl = 1010
Refinement top
Refinement on F2Primary atom site location: iterative
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.009Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.021All H-atom parameters refined
S = 1.12 w = 1/[σ2(Fo2) + (0.0076P)2 + 0.3355P]
where P = (Fo2 + 2Fc2)/3
1368 reflections(Δ/σ)max = 0.001
100 parametersΔρmax = 0.44 e Å3
0 restraintsΔρmin = 0.29 e Å3
Crystal data top
[Pt(NH3)4]Cl2·4NH3V = 671.15 (3) Å3
Mr = 402.25Z = 2
Monoclinic, P21/nMo Kα radiation
a = 7.6641 (2) ŵ = 10.83 mm1
b = 10.1601 (3) ÅT = 123 K
c = 8.7797 (2) Å0.2 × 0.1 × 0.1 mm
β = 100.975 (3)°
Data collection top
Agilent Xcalibur (Ruby, Gemini ultra)
diffractometer
1368 independent reflections
Absorption correction: analytical
[CrysAlis PRO (Agilent, 2012), using a multi-faceted crystal model based on expressions derived by Clark & Reid (1995)]
1276 reflections with I > 2σ(I)
Tmin = 0.162, Tmax = 0.462Rint = 0.022
14167 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0090 restraints
wR(F2) = 0.021All H-atom parameters refined
S = 1.12Δρmax = 0.44 e Å3
1368 reflectionsΔρmin = 0.29 e Å3
100 parameters
Special details top

Experimental. Absorption correction: CrysAlisPro, Agilent Technologies, Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark & Reid, 1995)

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) top
xyzUiso*/Ueq
Pt11.00000.50000.50000.01239 (4)
Cl10.40589 (5)0.33782 (4)0.26730 (5)0.01904 (8)
N10.9576 (2)0.48294 (16)0.72243 (19)0.0173 (3)
N20.8502 (2)0.33479 (16)0.43520 (18)0.0178 (3)
N30.7320 (2)0.4290 (2)0.0434 (2)0.0277 (4)
N40.5205 (3)0.6754 (2)0.3118 (2)0.0328 (4)
H2A0.740 (3)0.352 (2)0.405 (2)0.030 (6)*
H2B0.857 (3)0.282 (2)0.511 (3)0.028 (6)*
H1A0.941 (3)0.398 (2)0.747 (2)0.024 (5)*
H4A0.577 (4)0.675 (3)0.410 (4)0.073 (10)*
H1B0.858 (3)0.526 (2)0.732 (3)0.034 (6)*
H2C0.887 (3)0.291 (2)0.364 (3)0.028 (6)*
H3A0.648 (3)0.406 (3)0.086 (3)0.043 (7)*
H4B0.509 (4)0.586 (4)0.293 (4)0.078 (10)*
H4C0.428 (6)0.714 (5)0.315 (5)0.140 (19)*
H1C1.050 (4)0.5111 (19)0.792 (3)0.029 (6)*
H3B0.688 (4)0.486 (2)0.021 (4)0.049 (9)*
H3C0.752 (3)0.360 (3)0.014 (3)0.058 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Pt10.01155 (5)0.01255 (5)0.01316 (6)0.00056 (3)0.00256 (3)0.00081 (3)
Cl10.01979 (18)0.01656 (19)0.0203 (2)0.00148 (17)0.00270 (15)0.00201 (17)
N10.0185 (8)0.0176 (8)0.0165 (8)0.0000 (6)0.0049 (7)0.0015 (6)
N20.0181 (8)0.0173 (8)0.0177 (8)0.0025 (6)0.0026 (6)0.0012 (7)
N30.0256 (9)0.0332 (10)0.0227 (9)0.0001 (8)0.0003 (7)0.0057 (8)
N40.0483 (11)0.0238 (10)0.0252 (10)0.0071 (9)0.0041 (8)0.0005 (8)
Geometric parameters (Å, º) top
Pt1—N12.0471 (16)N2—H2B0.85 (2)
Pt1—N1i2.0471 (16)N2—H2C0.86 (2)
Pt1—N2i2.0519 (15)N3—H3A0.84 (3)
Pt1—N22.0519 (15)N3—H3B0.83 (3)
N1—H1A0.91 (2)N3—H3C0.90 (3)
N1—H1B0.90 (3)N4—H4A0.89 (3)
N1—H1C0.89 (3)N4—H4B0.93 (4)
N2—H2A0.85 (2)N4—H4C0.82 (5)
N1i—Pt1—N1179.999 (15)Pt1—N2—H2A112.9 (14)
N1—Pt1—N2i89.24 (6)Pt1—N2—H2B110.5 (14)
N1i—Pt1—N2i90.76 (6)Pt1—N2—H2C112.5 (14)
N1i—Pt1—N289.24 (6)H2A—N2—H2B106.4 (19)
N1—Pt1—N290.76 (6)H2A—N2—H2C108.9 (19)
N2—Pt1—N2i180.00 (7)H2B—N2—H2C105 (2)
Pt1—N1—H1A111.1 (13)H3A—N3—H3B105 (3)
Pt1—N1—H1B109.9 (16)H3A—N3—H3C105 (2)
Pt1—N1—H1C111.9 (16)H3B—N3—H3C105 (2)
H1A—N1—H1B106.9 (19)H4A—N4—H4B100 (3)
H1A—N1—H1C105.9 (18)H4A—N4—H4C103 (3)
H1B—N1—H1C111 (2)H4B—N4—H4C115 (4)
Symmetry code: (i) x+2, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···Cl10.85 (2)2.62 (2)3.4437 (16)162.8 (19)
N2—H2B···Cl1ii0.85 (2)2.52 (2)3.3594 (17)169.0 (19)
N1—H1A···Cl1ii0.91 (2)2.42 (2)3.3155 (17)170.2 (17)
N4—H4A···Cl1iii0.89 (3)2.81 (3)3.6330 (19)154 (2)
N1—H1B···Cl1iii0.90 (3)2.45 (3)3.3440 (17)173 (2)
N2—H2C···N4iv0.86 (2)2.16 (2)3.020 (2)178 (2)
N3—H3A···Cl10.84 (3)2.75 (3)3.583 (2)171 (2)
N4—H4B···Cl10.93 (4)2.64 (4)3.544 (2)166 (3)
N4—H4C···Cl1v0.82 (5)2.82 (5)3.608 (2)163 (4)
N1—H1C···N3i0.89 (3)2.08 (3)2.970 (2)178.1 (19)
N3—H3B···Cl1vi0.83 (3)2.80 (3)3.616 (2)168 (3)
Symmetry codes: (i) x+2, y+1, z+1; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1, y+1, z+1; (iv) x+3/2, y1/2, z+1/2; (v) x+1/2, y+1/2, z+1/2; (vi) x+1, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···Cl10.85 (2)2.62 (2)3.4437 (16)162.8 (19)
N2—H2B···Cl1i0.85 (2)2.52 (2)3.3594 (17)169.0 (19)
N1—H1A···Cl1i0.91 (2)2.42 (2)3.3155 (17)170.2 (17)
N4—H4A···Cl1ii0.89 (3)2.81 (3)3.6330 (19)154 (2)
N1—H1B···Cl1ii0.90 (3)2.45 (3)3.3440 (17)173 (2)
N2—H2C···N4iii0.86 (2)2.16 (2)3.020 (2)178 (2)
N3—H3A···Cl10.84 (3)2.75 (3)3.583 (2)171 (2)
N4—H4B···Cl10.93 (4)2.64 (4)3.544 (2)166 (3)
N4—H4C···Cl1iv0.82 (5)2.82 (5)3.608 (2)163 (4)
N1—H1C···N3v0.89 (3)2.08 (3)2.970 (2)178.1 (19)
N3—H3B···Cl1vi0.83 (3)2.80 (3)3.616 (2)168 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+1/2; (ii) x+1, y+1, z+1; (iii) x+3/2, y1/2, z+1/2; (iv) x+1/2, y+1/2, z+1/2; (v) x+2, y+1, z+1; (vi) x+1, y+1, z.
 

References

First citationAgilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.  Google Scholar
First citationAtoji, M., Richardson, J. W. & Rundle, R. E. (1957). J. Am. Chem. Soc. 79, 3017–3020.  CrossRef CAS Web of Science Google Scholar
First citationBourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2014). In preparation.  Google Scholar
First citationBrandenburg, K. & Putz, H. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationClark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887–897.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationCox, E. G. (1932). J. Chem. Soc. 6, 1912–1920.  CrossRef Google Scholar
First citationDesiraju, G. R. (2002). Acc. Chem. Res. 35, 565–573.  Web of Science CrossRef PubMed CAS Google Scholar
First citationDesiraju, G. R. (2007). Angew. Chem. Int. Ed. 46, 8342–8356.  Web of Science CrossRef CAS Google Scholar
First citationDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationGrassl, T. & Korber, N. (2014). Acta Cryst. E70, i32.  CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSmolentsev, A. I., Gubanov, A. I., Zadesenets, A. V., Plyusnin, P. E., Baidina, I. A. & Korenev, S. V. (2010). J. Struct. Chem. 51, 709–713.  Web of Science CrossRef CAS Google Scholar
First citationSteiner, T. (2002). Angew. Chem., 114, 50–80.  CrossRef Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds