Three novel non-centrosymmetric compounds of glycine: glycine lithium sulfate, glycine nickel dichloride dihydrate and glycine zinc sulfate trihydrate

The crystal structures of three compounds of glycine and inorganic materials are presented and discussed. The ortho­rhombic structure of glycinesulfatodilithium(I), [Li₂(SO₄)(C₂H₅NO₂)]_n, consists of corrugated sheets of [LiO₄] and [SO₄] tetrahedra. The glycine mol­ecules are located between these sheets. The main features of the monoclinic structure of di­aqua­di­chloro­glycinenickel(II), [NiCl₂(C₂H₅NO₂)(H₂O)₂]_n, are helical chains of [NiO₄Cl₂] octahedra connected by glycine mol­ecules. The orthorhombic structure of tri­aqua­glycinesulfatozinc(II), [Zn(SO₄)(C₂H₅NO₂)(H₂O)₃]_n, is made up of [O₃SOZnO₅] clusters. These clusters are linked by glycine mol­ecules into zigzag chains. All three compounds are examples of non-centrosymmetric glycine compounds.

S1. Comment

In the course of our search for new non-centrosymmetric compounds, we have investigated compounds of glycine and inorganic materials. The Cambridge Structural Database (CSD; Allen, 2002) contains over 200 glycine compounds, nearly a third of which are non-centrosymmetric. However, in most of these substances, glyince is combined with other organic molecules. Only 20 compounds of glycine and inorganic materials were found. We focus here exclusively on such compounds, rather than structures containing other organic molecules. In contrast to the chiral amino acids, non-chiral glycine (as a structural unit) cannot enforce non-centrosymmetry of a crystal structure. However, many compounds of glycine are polar [e.g. glycine sodium nitrate, space group Cc (Krishnakumar et al., 2001), glycine calcium dichloride, space group Pb2₁a (Ravikumar et al., 1986), glycine calcium dibromide, space group Pbc2₁ (Mohana Rao & Natarajan, 1980) and glycine zinc chloride, space group Pbn2₁ (Hariharan et al., 1989)]. Even two of the three polymorphs of pure glycine are non-centrosymmetric, namely β-glycine (space group P2₁; Drebushchak et al., 2002) and γ-glycine (space group P32; Shimon et al., 1986). Since the glycine molecule as an amphoteric can assume cationic, anionic and zwitterionic forms, the molecule can combine with anionic, cationic and overall neutral chemical constituents, and thus a large number of possible glycine compounds exist. We have therefore started a study of such compounds of glycine and inorganic materials. We present here three new non-centrosymmetric structures of this type. All three represent new structure types, i.e. no isostructural compounds are known.

The structure of glycine lithium sulfate (Fig. 1) is composed of corrugated sheets of [LiO₄] tetrahedra and [SO₄] tetrahedra parallel to (001). These sheets consist of three crystallographically different tetrahedra (around Li1, Li2 and S) that are connected by common corners (represented by atoms O2S, O3S and O4S; Fig. 4). The tip of each tetrahedron (i.e. the corner not connected to other tetrahedra) faces away from the sheet. Since the O atoms forming the tips of the Li1- and Li2-tetrahedra belong to the carboxyl group of the glycine molecule, these neighboring tips are close to one another [O1—O2 = 2.238 (2) Å], twisting the polyhedra towards the glycine molecule and corrugating the sheets (Fig. 5). Consequently, the glycine molecules are located in the interstices between the sheets. The sheets are therefore connected only by weak hydrogen bonds. It is interesting to note that the carboxyl groups, which effect the corrugation of the sheet, are spread more than usual; the O1—C1—O2 angle is 126.4 (2) ° and the O1—O2 distance is 2.238 (2) Å. The average values of these parameters based on literature data are 125.2° and 2.214 Å, respectively. A test for possible higher symmetry, using the program PLATON (Spek, 2000), suggests the space group Pnma, with a probability of 92%. However, refinement in this space group shows that the position of the NH₃ group does not suit this symmetry (imagine these alleged mirror planes horizontally in Fig. 5).

The crystal structure of glycine nickel dichloride dihydrate (Fig. 2) is altogether different. It is composed of distorted [NiO₄Cl₂] octhedra, with atoms Cl1 and Cl2 located at adjacent corners. The two opposite corners are occupied by O atoms from the carboxyl group of the glycine molecule (O1 and O2). The two remaining corners are occupied by O atoms of water molecules (O1W and O2W). Atoms O1 and O2 of one Ni coordination sphere belong to two different glycine molecules. Thus each molecule connects two Ni polyhedra, forming infinite chains along [010]. Each chain is actually a left-handed helix around a 2₁ screw axis (Fig. 6). These chains are connected to one another by hydrogen bonds. Similar chains are common in L-malates, e.g. copper dihydrogen dimalate (Fleck et al., 2004).

Glycine zinc sulfate trihydrate (Fig. 3) can also be described as having a chain structure. Slightly irregular [ZnO₆] octahedra are connected to [SO₄] tetrahedra by one common corner, namely atom O3S, thus forming [O₃SOZnO₅] clusters (Fig. 7). Three corners of the [ZnO₆] octahedra are occupied by O atoms of water molecules. The remaining two corners are occupied by O atoms from the caboxyl group of the glycine molecules. Thus these [O₃SOZnO₅] zinc sulfate clusters are connected to one another by the glycine molecules, thus forming zigzag chains along [100]. The chain is not a spiral, as reported for the above nickel compound, but can be described by means of the a-glide plane in (010). More than 70 years ago, Dubský & Rabas (1931) described a pentahydrate, (C₂H₅NO₂)ZnSO₄·5H₂O. However, in our experiments, we obtained only the trihydrate, which in turn was not reported by Dubský & Rabas (1931).

We have compared the geometry of the glycine molecules in the title compounds and in α-glycine (Legros & Kvick, 1980), β-glycine (Drebushchak et al., 2002), γ-glycine (Shimon et al., 1986), glycine nickel sulfate hydrate (Peterkova et al., 1991) and glycine zinc chloride (Hariharan et al., 1989). Obviously, the molecular conformation is the geometrical feature with the highest degree of freedom. Comparing the O—C1—C2—N torsion angles (assuming no chemical difference between the two O atoms of the carboxyl group) we found more or less antiperiplanar (i.e. trans) conformations. In some compounds, large deviations from the ideal trans conformation (i.e. a torsion angle of 180 °) were observed [e.g. −157.4 (2) ° in β-glycine and −163.4 (2) ° in glycine zinc chloride]. In the title compounds, the torsion angles are −170.98 (15) (glycine lithium sulfate), −178.78 (13) (glycine nickel dichloride dihydrate) and −176.85 (18) ° (glycine zinc sulfate trihydrate). The differences in the interatomic distances and angles are much smaller. None of the distances and angles deviate significantly from the average values calculated from the structural data of the above compounds [C1—O1 = 1.25 (2) Å, C1—O2 = 1.26 (2) Å, C1—C2 = 1.52 (2) Å, C2—N = 1.48 (1) Å and O1—C1—O2 = 125.7 (19) °; cf. Tables XXX). The only noteworthy deviation from these values occurs in glycine zinc chloride, where both carboxyl O atoms are virtually equidistant from the C atom. Obviously, the mesomeric effect is more pronounced in this salt than in the other compounds.

S2. Experimental

The crystals of the title compounds were grown from aqueous solutions of glycine and lithium sulfate, nickel dichloride or zinc sulfate, respectively, in a stochiometric ratio. The solutions were evaporated slowly at a temperature of approximately 295 K over a period of four months. The syntheses yielded crystals of up to several millimeters in diameter.

Computing details

For all compounds, data collection: COLLECT (Nonius, 2003); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997). Molecular graphics: DIAMOND (Bergerhoff et al., 1997) for (I); ATOMS (Dowty, 1999) for (II), (III). For all compounds, software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. : The connectivity in glycine lithium sulfate, (C2H5NO2)Li2(SO4), with displacement ellipsoids at the 50% probability level. [Symmetry codes: (i) 3/2 − x, 1/2 + y, z + 1/2; (ii) x, 1 + y, z; (iii) 3/2 − x, y − 1/2, z − 1/2; (iv) 3/2 − x, y + 1/2, z + 1/2.]
	Fig. 2. : The connectivity in glycine nickel dichloride dihydrate, (C2H5NO2)NiCl2·2(H2O), with displacement ellipsoids at the 50% probability level. [Symmetry code: (i) 2 − x, y + 1/2, 1 − z.]
	Fig. 3. : The connectivity in glycine zinc sulfate trihydrate, (C2H5NO2)Zn (SO4)·3(H2O), with displacement ellipsoids at the 50% probability level. [Symmetry code: (i) x − 1/2, − y, z.]
	Fig. 4. : The crystal structure of glycine lithium sulfate, (C2H5NO2)Li2(SO4), in a view perpendicular to the sheets. In the online version of the journal, [LiO4] tetrahedra are shown in red and [SO4] tetrahedra in yellow.
	Fig. 5. : The crystal structure of glycine lithium sulfate, viewed along [010]. The corrugated sheets are oriented vertically. Note the position of the acid group, forcing the tips of the Li1 and Li2 tetrahedra together. Colours in the online version of the journal are as in Fig. 4.
	Fig. 6. : The crystal structure of glycine nickel dichloride dihydrate (C2H5NO2)NiCl2·2(H2O), in a view along [010], along the chains.
	Fig. 7. : The crystal structure of glycine zinc sulfate trihydrate, (C2H5NO2)Zn (SO4)·3(H2O), in a view along [010]. The chains are oriented horizontally. In the online version of the journal, [ZnO6] octahedra are coloured grey and [SO4] tetrahedra are coloured yellow.

(I)

Crystal data

[Li2(SO4)(C2H5O2N)]	Dx = 1.953 Mg m^−3
Mr = 185.01	Melting point: not determined K
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 1054 reflections
a = 16.423 (3) Å	θ = 4.1–30.0°
b = 5.005 (1) Å	µ = 0.49 mm^−1
c = 7.654 (2) Å	T = 293 K
V = 629.1 (2) Å^3	Prism, colourless
Z = 4	0.40 × 0.20 × 0.20 mm
F(000) = 376

Data collection

Nonius Kappa CCD diffractometer	1653 independent reflections
Radiation source: fine-focus sealed tube	1582 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.000
Detector resolution: 9 pixels mm^-1	θmax = 30.0°, θmin = 4.3°
ϕ and ω scans	h = −22→23
Absorption correction: multi-scan (Otwinowski & Minor, 1997)	k = −7→7
Tmin = 0.827, Tmax = 0.908	l = −10→10
1653 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.025	w = 1/[σ^2(Fo^2) + (0.0387P)^2 + 0.088P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.066	(Δ/σ)max = 0.001
S = 1.09	Δρmax = 0.28 e Å^−3
1653 reflections	Δρmin = −0.36 e Å^−3
130 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.013 (7)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.021 (4)

Special details

Experimental. Single-crystal X-ray intensity data were collected at 293 K on a Nonius Kappa diffractometer with CCD-area detector, using 282 frames with phi- and omega-increments of 1 degrees and a counting time of 20 s per frame. The crystal- to-detector-distance was 30 mm. The whole ewald sphere was measured. The reflection data were processed with the Nonius program suite DENZO-SMN and corrected for Lorentz, polarization, background and absorption effects (Otwinowski and Minor, 1997). The crystal structure was determined by Direct methods (SHELXS97, Sheldrick, 1997) and subsequent Fourier and difference Fourier syntheses, followed by full-matrix least-squares refinements on F² (SHELXL97, Sheldrick, 1997). All hydrogen atoms were refined freely.

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 (Ų)

	x	y	z	Uiso*/Ueq
Li1	0.6948 (3)	0.7389 (6)	0.4648 (5)	0.0179 (8)
Li2	0.7977 (2)	0.2373 (7)	0.5271 (5)	0.0201 (8)
S	0.668617 (16)	0.23198 (5)	0.24330 (12)	0.01183 (11)
O1S	0.58049 (6)	0.2620 (2)	0.2328 (5)	0.0247 (3)
O2S	0.69785 (7)	0.3563 (3)	0.40610 (17)	0.0203 (3)
O3S	0.70821 (8)	0.3604 (3)	0.09065 (18)	0.0196 (3)
O4S	0.69165 (5)	−0.05380 (17)	0.2446 (3)	0.01856 (19)
O1	0.60013 (8)	0.8445 (3)	0.59255 (17)	0.0234 (3)
O2	0.61244 (9)	0.8091 (3)	0.8828 (2)	0.0266 (3)
C1	0.59173 (7)	0.9283 (2)	0.7464 (3)	0.0167 (2)
C2	0.55194 (11)	1.1987 (3)	0.7733 (2)	0.0227 (4)
H1C	0.5123 (18)	1.183 (6)	0.863 (4)	0.039 (7)*
H2C	0.5921 (15)	1.320 (5)	0.810 (3)	0.034 (6)*
N	0.51813 (10)	1.3043 (4)	0.6094 (2)	0.0266 (3)
H1N	0.5538 (18)	1.294 (5)	0.530 (5)	0.043 (7)*
H2N	0.471 (2)	1.205 (6)	0.597 (5)	0.064 (9)*
H3N	0.4959 (18)	1.452 (6)	0.627 (4)	0.052 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Li1	0.0202 (16)	0.0154 (19)	0.0182 (19)	0.0008 (10)	−0.0008 (14)	0.0011 (11)
Li2	0.0257 (19)	0.0181 (19)	0.0166 (19)	0.0004 (11)	−0.0002 (15)	0.0021 (11)
S	0.01380 (15)	0.01120 (15)	0.01050 (15)	0.00120 (9)	0.0003 (2)	0.0005 (2)
O1S	0.0128 (5)	0.0316 (5)	0.0296 (8)	0.0031 (3)	0.0002 (7)	0.0056 (6)
O2S	0.0305 (6)	0.0165 (7)	0.0138 (6)	0.0024 (5)	−0.0042 (5)	−0.0034 (6)
O3S	0.0250 (6)	0.0154 (6)	0.0183 (6)	0.0023 (5)	0.0076 (5)	0.0051 (6)
O4S	0.0316 (5)	0.0114 (4)	0.0127 (4)	0.0032 (3)	−0.0005 (6)	0.0003 (6)
O1	0.0256 (6)	0.0248 (6)	0.0199 (6)	0.0035 (5)	0.0041 (5)	−0.0024 (6)
O2	0.0307 (7)	0.0295 (7)	0.0197 (7)	0.0047 (6)	−0.0049 (6)	0.0041 (6)
C1	0.0148 (5)	0.0172 (5)	0.0181 (5)	−0.0018 (4)	0.0000 (8)	0.0012 (8)
C2	0.0307 (8)	0.0189 (6)	0.0183 (10)	0.0023 (6)	−0.0039 (6)	−0.0016 (6)
N	0.0350 (8)	0.0245 (7)	0.0203 (7)	0.0119 (6)	−0.0020 (6)	−0.0023 (6)

Geometric parameters (Å, º)

Li1—O1	1.911 (4)	O3S—Li1^iii	1.958 (4)
Li1—O3S^i	1.958 (4)	O4S—Li2^iii	1.973 (5)
Li1—O2S	1.968 (4)	O4S—Li1^vi	1.980 (4)
Li1—O4S^ii	1.980 (4)	O1—C1	1.258 (3)
Li2—O2^iii	1.878 (4)	O2—C1	1.249 (3)
Li2—O3S^iv	1.950 (4)	C1—C2	1.517 (2)
Li2—O4S^i	1.973 (5)	C2—N	1.470 (2)
Li2—O2S	1.976 (4)	C2—H1C	0.95 (3)
S—O1S	1.4573 (11)	C2—H2C	0.94 (3)
S—O2S	1.4732 (17)	N—H1N	0.84 (3)
S—O4S	1.4796 (9)	N—H2N	0.92 (4)
S—O3S	1.4837 (17)	N—H3N	0.83 (3)
O3S—Li2^v	1.950 (4)
O1—Li1—O3S^i	108.9 (2)	O2^iii—Li2—Li1	100.67 (16)
O1—Li1—O2S	114.0 (2)	O3S^iv—Li2—Li1	143.47 (16)
O3S^i—Li1—O2S	113.21 (19)	O4S^i—Li2—Li1	75.27 (14)
O1—Li1—O4S^ii	105.62 (18)	O2S—Li2—Li1	38.93 (8)
O3S^i—Li1—O4S^ii	106.10 (19)	S^i—Li2—Li1	61.04 (11)
O2S—Li1—O4S^ii	108.42 (19)	S—Li2—Li1	60.69 (7)
O1—Li1—S^ii	86.87 (13)	Li1^vi—Li2—Li1	109.87 (11)
O3S^i—Li1—S^ii	97.93 (13)	O2^iii—Li2—Li1^iv	124.0 (2)
O2S—Li1—S^ii	132.03 (18)	O3S^iv—Li2—Li1^iv	75.82 (15)
O4S^ii—Li1—S^ii	24.72 (6)	O4S^i—Li2—Li1^iv	32.07 (9)
O1—Li1—Li2^ii	98.32 (15)	O2S—Li2—Li1^iv	119.9 (2)
O3S^i—Li1—Li2^ii	38.60 (9)	S^i—Li2—Li1^iv	56.32 (10)
O2S—Li1—Li2^ii	144.83 (17)	S—Li2—Li1^iv	137.78 (19)
O4S^ii—Li1—Li2^ii	73.69 (13)	Li1^vi—Li2—Li1^iv	100.27 (14)
S^ii—Li1—Li2^ii	59.96 (10)	Li1—Li2—Li1^iv	100.00 (14)
O1—Li1—Li2	126.58 (16)	O1S—S—O2S	109.07 (13)
O3S^i—Li1—Li2	74.29 (10)	O1S—S—O4S	110.73 (6)
O2S—Li1—Li2	39.12 (14)	O2S—S—O4S	108.62 (11)
O4S^ii—Li1—Li2	125.18 (15)	O1S—S—O3S	110.32 (12)
S^ii—Li1—Li2	146.52 (12)	O2S—S—O3S	109.89 (6)
Li2^ii—Li1—Li2	109.87 (11)	O4S—S—O3S	108.18 (10)
O1—Li1—Li2^v	122.8 (2)	O1S—S—Li1^vi	104.84 (11)
O3S^i—Li1—Li2^v	117.6 (2)	O2S—S—Li1^vi	79.86 (10)
O2S—Li1—Li2^v	76.61 (14)	O3S—S—Li1^vi	137.11 (10)
O4S^ii—Li1—Li2^v	31.94 (9)	O1S—S—Li2^iii	103.61 (12)
S^ii—Li1—Li2^v	56.42 (10)	O2S—S—Li2^iii	138.41 (10)
Li2^ii—Li1—Li2^v	97.92 (14)	O3S—S—Li2^iii	81.03 (10)
Li2—Li1—Li2^v	97.67 (13)	Li1^vi—S—Li2^iii	67.26 (6)
O2^iii—Li2—O3S^iv	111.8 (2)	O1S—S—Li2	137.07 (15)
O2^iii—Li2—O4S^i	109.00 (19)	O4S—S—Li2	79.94 (10)
O3S^iv—Li2—O4S^i	107.9 (2)	O3S—S—Li2	104.69 (10)
O2^iii—Li2—O2S	108.6 (2)	Li1^vi—S—Li2	60.45 (11)
O3S^iv—Li2—O2S	111.51 (19)	Li2^iii—S—Li2	105.71 (8)
O4S^i—Li2—O2S	108.00 (19)	Li2^iii—O4S—Li1^vi	116.00 (10)
O2^iii—Li2—S^i	91.25 (14)	O2—C1—O1	126.41 (13)
O3S^iv—Li2—S^i	131.57 (19)	O2—C1—C2	115.5 (2)
O4S^i—Li2—S^i	24.49 (6)	O1—C1—C2	118.13 (18)
O2S—Li2—S^i	99.28 (14)	N—C2—C1	111.59 (16)
O2^iii—Li2—S	97.43 (16)	N—C2—H1C	112.8 (18)
O3S^iv—Li2—S	97.75 (15)	C1—C2—H1C	108.7 (19)
O4S^i—Li2—S	132.06 (17)	N—C2—H2C	106.8 (16)
O2S—Li2—S	24.11 (8)	C1—C2—H2C	108.3 (16)
S^i—Li2—S	121.71 (12)	H1C—C2—H2C	109 (2)
O2^iii—Li2—Li1^vi	119.99 (16)	C2—N—H1N	109 (2)
O3S^iv—Li2—Li1^vi	38.77 (13)	C2—N—H2N	102 (2)
O4S^i—Li2—Li1^vi	127.87 (14)	H1N—N—H2N	118 (3)
O2S—Li2—Li1^vi	73.32 (10)	C2—N—H3N	110 (2)
S^i—Li2—Li1^vi	148.74 (12)	H1N—N—H3N	118 (3)
S—Li2—Li1^vi	59.60 (7)	H2N—N—H3N	97 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N—H1N···O1S^ii	0.84 (3)	2.32 (4)	3.066 (4)	147 (3)
N—H2N···O2^vii	0.92 (4)	2.14 (4)	2.816 (2)	130 (3)
N—H3N···O1S^viii	0.83 (3)	2.07 (3)	2.868 (2)	160 (3)

Symmetry codes: (ii) x, y+1, z; (vii) −x+1, −y+2, z−1/2; (viii) −x+1, −y+2, z+1/2.

(II)

Crystal data

[NiCl2(C2H5O2N)(H2O)2]	F(000) = 244
Mr = 240.71	Dx = 2.142 Mg m^−3
Monoclinic, P21	Melting point: not determined K
Hall symbol: P 2yb	Mo Kα radiation, λ = 0.71073 Å
a = 8.203 (2) Å	Cell parameters from 1197 reflections
b = 5.475 (1) Å	θ = 4.1–30.0°
c = 8.311 (2) Å	µ = 3.27 mm^−1
β = 90.97 (3)°	T = 293 K
V = 373.21 (14) Å^3	Prism, green
Z = 2	0.20 × 0.10 × 0.10 mm

Data collection

Nonius Kappa CCD diffractometer	2170 independent reflections
Radiation source: fine-focus sealed tube	2142 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.000
Detector resolution: 9 pixels mm^-1	θmax = 30.0°, θmin = 4.5°
ω scans	h = −11→11
Absorption correction: multi-scan (Otwinowski & Minor, 1997)	k = −7→7
Tmin = 0.561, Tmax = 0.736	l = −11→11
2170 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.016	w = 1/[σ^2(Fo^2) + (0.0166P)^2 + 0.065P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.038	(Δ/σ)max = 0.003
S = 1.13	Δρmax = 0.29 e Å^−3
2170 reflections	Δρmin = −0.34 e Å^−3
128 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.127 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.002 (8)

Special details

Experimental. Single-crystal X-ray intensity data were collected at 293 K on a Nonius Kappa diffractometer with CCD-area detector, using 318 frames with an omega-increment of 2 degrees and a counting time of 30 s per frame. The crystal to detector distance was 25 mm. The whole ewald sphere was measured. The reflection data were processed with the Nonius program suite DENZO-SMN and corrected for Lorentz, polarization, background and absorption effects (Otwinowski and Minor, 1997). The crystal structure was determined by automatic patterson methods (SHELXS97, Sheldrick, 1997) and subsequent Fourier and difference Fourier syntheses, followed by full-matrix least-squares refinements on F² (SHELXL97, Sheldrick, 1997). All hydrogen atoms were refined freely.

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 (Ų)

	x	y	z	Uiso*/Ueq
Ni	0.784803 (18)	0.78457 (3)	0.334887 (18)	0.01347 (6)
Cl1	0.54116 (4)	0.54991 (7)	0.25002 (4)	0.02017 (8)
Cl2	0.77352 (4)	0.99840 (7)	0.08732 (4)	0.02162 (9)
O1	1.00165 (12)	0.4518 (2)	0.58500 (13)	0.0183 (2)
O2	0.76111 (13)	0.6377 (2)	0.56224 (13)	0.0179 (2)
C1	0.86615 (16)	0.5169 (3)	0.63931 (16)	0.0149 (2)
C2	0.8260 (2)	0.4484 (4)	0.8103 (2)	0.0277 (4)
H1C	0.830 (3)	0.259 (6)	0.821 (3)	0.041 (6)*
H2C	0.895 (3)	0.509 (5)	0.879 (3)	0.043 (7)*
N	0.66229 (16)	0.5314 (3)	0.85727 (17)	0.0212 (3)
H1N	0.648 (4)	0.541 (8)	0.960 (4)	0.074 (10)*
H2N	0.580 (5)	0.435 (8)	0.804 (5)	0.090 (13)*
H3N	0.637 (5)	0.679 (8)	0.814 (5)	0.086 (13)*
O1W	0.92928 (14)	0.4953 (2)	0.26258 (14)	0.0200 (2)
H1W1	0.889 (4)	0.364 (6)	0.225 (4)	0.063 (9)*
H2W1	0.964 (3)	0.449 (6)	0.364 (4)	0.046 (7)*
O2W	0.65320 (18)	1.0653 (3)	0.43031 (17)	0.0329 (3)
H1W2	0.598 (3)	1.046 (7)	0.520 (4)	0.063 (9)*
H2W2	0.631 (3)	1.180 (6)	0.386 (4)	0.047 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni	0.01401 (8)	0.01378 (9)	0.01262 (9)	0.00057 (6)	0.00000 (5)	0.00155 (7)
Cl1	0.01818 (15)	0.02103 (17)	0.02124 (16)	−0.00242 (12)	−0.00178 (11)	0.00289 (13)
Cl2	0.02621 (17)	0.02273 (18)	0.01585 (15)	−0.00328 (13)	−0.00192 (12)	0.00540 (13)
O1	0.0166 (5)	0.0224 (5)	0.0160 (5)	0.0052 (4)	0.0011 (4)	0.0028 (4)
O2	0.0175 (5)	0.0220 (5)	0.0143 (5)	0.0047 (4)	0.0007 (4)	0.0052 (4)
C1	0.0165 (6)	0.0140 (6)	0.0142 (6)	−0.0013 (5)	0.0000 (4)	0.0013 (5)
C2	0.0197 (7)	0.0439 (11)	0.0198 (7)	0.0079 (7)	0.0042 (6)	0.0145 (7)
N	0.0212 (6)	0.0249 (7)	0.0177 (6)	−0.0015 (5)	0.0042 (4)	−0.0010 (5)
O1W	0.0228 (5)	0.0183 (5)	0.0191 (5)	0.0032 (4)	0.0006 (4)	−0.0011 (4)
O2W	0.0459 (8)	0.0223 (6)	0.0312 (6)	0.0161 (6)	0.0197 (6)	0.0100 (6)

Geometric parameters (Å, º)

Ni—O2W	2.0457 (14)	C2—H1C	1.04 (4)
Ni—O2	2.0658 (11)	C2—H2C	0.86 (3)
Ni—O1W	2.0732 (12)	N—H1N	0.86 (3)
Ni—O1^i	2.0762 (11)	N—H2N	0.96 (4)
Ni—Cl2	2.3677 (6)	N—H3N	0.91 (4)
Ni—Cl1	2.4688 (6)	O1W—H1W1	0.85 (4)
O1—C1	1.2582 (17)	O1W—H2W1	0.92 (3)
O2—C1	1.2534 (18)	O2W—H1W2	0.89 (3)
C1—C2	1.512 (2)	O2W—H2W2	0.75 (3)
C2—N	1.477 (2)
O2W—Ni—O2	83.08 (5)	N—C2—C1	112.68 (13)
O2W—Ni—O1W	173.85 (5)	N—C2—H1C	108.1 (14)
O2—Ni—O1W	91.76 (5)	C1—C2—H1C	108.7 (14)
O2W—Ni—O1^i	89.56 (6)	N—C2—H2C	107.1 (17)
O2—Ni—O1^i	88.30 (5)	C1—C2—H2C	112.0 (17)
O1W—Ni—O1^i	86.93 (5)	H1C—C2—H2C	108 (2)
O2W—Ni—Cl2	87.27 (4)	C2—N—H1N	115 (2)
O2—Ni—Cl2	169.89 (3)	C2—N—H2N	110 (2)
O1W—Ni—Cl2	98.05 (4)	H1N—N—H2N	113 (3)
O1^i—Ni—Cl2	94.64 (4)	C2—N—H3N	112 (3)
O2W—Ni—Cl1	94.11 (5)	H1N—N—H3N	108 (4)
O2—Ni—Cl1	88.31 (4)	H2N—N—H3N	99 (3)
O1W—Ni—Cl1	89.06 (4)	Ni—O1W—H1W1	122 (2)
O1^i—Ni—Cl1	174.67 (3)	Ni—O1W—H2W1	96.6 (18)
Cl2—Ni—Cl1	89.40 (3)	H1W1—O1W—H2W1	102 (3)
O2—C1—O1	124.74 (13)	Ni—O2W—H1W2	121 (2)
O2—C1—C2	116.91 (13)	Ni—O2W—H2W2	125 (2)
O1—C1—C2	118.35 (13)	H1W2—O2W—H2W2	113 (3)

Symmetry code: (i) −x+2, y+1/2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N—H1N···Cl1^ii	0.86 (3)	2.58 (3)	3.4296 (17)	167 (3)
N—H2N···Cl1^iii	0.96 (4)	2.37 (4)	3.2372 (16)	150 (4)
N—H3N···Cl1^iv	0.91 (4)	2.55 (4)	3.4042 (17)	156 (4)
O1W—H1W1···Cl2^v	0.85 (4)	2.49 (4)	3.3304 (14)	174 (3)
O1W—H2W1···O1	0.92 (3)	1.86 (3)	2.7451 (17)	161 (3)
O2W—H1W2···Cl1^iv	0.89 (3)	2.24 (3)	3.1226 (16)	172 (3)
O2W—H2W2···Cl1^vi	0.75 (3)	2.43 (3)	3.1756 (15)	176 (3)

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

(III)

Crystal data

[Zn(SO4)(C2H5O2N)(H2O)3]	Dx = 2.206 Mg m^−3
Mr = 290.55	Melting point: not determined K
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 2456 reflections
a = 8.440 (2) Å	θ = 3.5–37.8°
b = 8.278 (2) Å	µ = 3.08 mm^−1
c = 12.521 (3) Å	T = 293 K
V = 874.8 (4) Å^3	Prism, colourless
Z = 4	0.10 × 0.05 × 0.05 mm
F(000) = 592

Data collection

Nonius Kappa CCD diffractometer	4460 independent reflections
Radiation source: fine-focus sealed tube	3901 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.000
Detector resolution: 9 pixels mm^-1	θmax = 37.8°, θmin = 3.5°
ω–scans	h = −14→14
Absorption correction: multi-scan (Otwinowski & Minor, 1997)	k = −14→14
Tmin = 0.748, Tmax = 0.861	l = −21→21
4460 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.030	w = 1/[σ^2(Fo^2) + (0.023P)^2 + 0.336P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.067	(Δ/σ)max = 0.001
S = 1.02	Δρmax = 0.64 e Å^−3
4460 reflections	Δρmin = −0.47 e Å^−3
172 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.0018 (8)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.006 (3)

Special details

Experimental. Single-crystal X-ray intensity data were collected at 293 K on a Nonius Kappa diffractometer with CCD-area detector, using 476 frames with an omega-increment of 2 degrees and a counting time of 100 s per frame. The crystal to detector distance was 25 mm. The whole ewald sphere was measured. The reflection data were processed with the Nonius program suite DENZO-SMN and corrected for Lorentz, polarization, background and absorption effects (Otwinowski and Minor, 1997). The crystal structure was determined by automatic patterson methods (SHELXS97, Sheldrick, 1997) and subsequent Fourier and difference Fourier syntheses, followed by full-matrix least-squares refinements on F² (SHELXL97, Sheldrick, 1997). All hydrogen atoms were refined freely. The crystals proved to racemic twins, therefore TWIN refinement was employed.

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 (Ų)

	x	y	z	Uiso*/Ueq
Zn	0.04955 (2)	0.19651 (2)	0.497340 (18)	0.01759 (5)
S	0.02497 (5)	0.27959 (5)	0.75223 (4)	0.01762 (7)
O1S	−0.1399 (2)	0.2522 (2)	0.78387 (15)	0.0325 (3)
O2S	0.1220 (2)	0.1356 (2)	0.77214 (14)	0.0294 (3)
O3S	0.0306 (2)	0.32374 (19)	0.63729 (12)	0.0290 (3)
O4S	0.0917 (2)	0.4204 (2)	0.81091 (14)	0.0284 (3)
O1	0.27904 (15)	0.11371 (17)	0.50738 (15)	0.0246 (3)
O2	0.51595 (18)	0.03689 (17)	0.56383 (14)	0.0262 (3)
C1	0.4077 (2)	0.1384 (2)	0.55399 (14)	0.0171 (3)
C2	0.4362 (2)	0.3058 (2)	0.60084 (19)	0.0231 (3)
H1C	0.370 (5)	0.318 (5)	0.660 (3)	0.049 (10)*
H2C	0.416 (4)	0.386 (5)	0.539 (3)	0.038 (9)*
N	0.5949 (3)	0.3198 (3)	0.6477 (2)	0.0326 (4)
H1N	0.668 (5)	0.306 (4)	0.590 (3)	0.043 (10)*
H2N	0.606 (5)	0.406 (7)	0.688 (4)	0.067 (12)*
H3N	0.592 (6)	0.254 (7)	0.688 (5)	0.077 (17)*
O1W	0.1282 (2)	0.41992 (19)	0.43295 (13)	0.0243 (3)
H1W1	0.065 (4)	0.460 (4)	0.406 (3)	0.027 (8)*
H2W1	0.195 (6)	0.404 (5)	0.399 (4)	0.066 (14)*
O2W	0.0595 (2)	0.1182 (2)	0.33418 (14)	0.0268 (3)
H1W2	0.150 (5)	0.120 (5)	0.317 (3)	0.045 (10)*
H2W2	0.015 (6)	0.030 (6)	0.318 (4)	0.070 (13)*
O3W	−0.19955 (18)	0.2132 (2)	0.47292 (13)	0.0249 (3)
H1W3	−0.218 (5)	0.223 (5)	0.403 (4)	0.059 (12)*
H2W3	−0.223 (5)	0.120 (6)	0.477 (4)	0.066 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn	0.01679 (7)	0.01588 (8)	0.02010 (8)	0.00075 (6)	−0.00041 (9)	0.00027 (8)
S	0.01806 (16)	0.01866 (16)	0.01614 (16)	−0.00037 (13)	0.00055 (13)	0.00120 (14)
O1S	0.0208 (7)	0.0430 (10)	0.0338 (8)	−0.0044 (6)	0.0043 (6)	0.0028 (7)
O2S	0.0280 (7)	0.0230 (7)	0.0371 (9)	0.0044 (6)	−0.0079 (6)	0.0046 (6)
O3S	0.0494 (10)	0.0202 (6)	0.0173 (6)	0.0033 (6)	0.0047 (6)	0.0017 (5)
O4S	0.0273 (7)	0.0261 (7)	0.0319 (8)	0.0000 (6)	−0.0051 (6)	−0.0085 (6)
O1	0.0170 (5)	0.0229 (5)	0.0339 (8)	0.0015 (4)	−0.0035 (6)	−0.0044 (6)
O2	0.0231 (6)	0.0169 (6)	0.0387 (8)	0.0039 (5)	−0.0089 (6)	−0.0068 (6)
C1	0.0167 (6)	0.0175 (7)	0.0173 (6)	−0.0006 (5)	0.0016 (5)	−0.0011 (5)
C2	0.0213 (8)	0.0170 (7)	0.0311 (9)	−0.0001 (6)	−0.0020 (6)	−0.0047 (7)
N	0.0244 (8)	0.0311 (10)	0.0425 (11)	0.0000 (7)	−0.0061 (8)	−0.0173 (9)
O1W	0.0271 (7)	0.0212 (6)	0.0244 (7)	0.0012 (5)	0.0038 (5)	0.0051 (5)
O2W	0.0269 (7)	0.0261 (7)	0.0274 (7)	−0.0008 (6)	0.0007 (5)	−0.0073 (6)
O3W	0.0192 (6)	0.0250 (7)	0.0305 (8)	0.0005 (5)	−0.0016 (5)	0.0038 (5)

Geometric parameters (Å, º)

Zn—O3S	2.0507 (16)	C2—N	1.467 (3)
Zn—O1	2.0584 (13)	C2—H1C	0.93 (4)
Zn—O2^i	2.1229 (15)	C2—H2C	1.03 (4)
Zn—O1W	2.1238 (16)	N—H1N	0.95 (4)
Zn—O3W	2.1290 (16)	N—H2N	0.88 (5)
Zn—O2W	2.1449 (18)	N—H3N	0.75 (6)
S—O1S	1.4642 (18)	O1W—H1W1	0.71 (3)
S—O2S	1.4675 (16)	O1W—H2W1	0.72 (5)
S—O3S	1.4857 (17)	O2W—H1W2	0.79 (4)
S—O4S	1.4888 (16)	O2W—H2W2	0.85 (5)
O1—C1	1.249 (2)	O3W—H1W3	0.89 (5)
O2—C1	1.248 (2)	O3W—H2W3	0.80 (5)
C1—C2	1.524 (3)
O3S—Zn—O1	101.09 (7)	O1—C1—C2	117.75 (16)
O3S—Zn—O2^i	97.00 (7)	N—C2—C1	111.71 (16)
O1—Zn—O2^i	78.38 (6)	N—C2—H1C	103 (3)
O3S—Zn—O1W	84.35 (7)	C1—C2—H1C	108 (2)
O1—Zn—O1W	91.10 (7)	N—C2—H2C	113.6 (18)
O2^i—Zn—O1W	169.47 (6)	C1—C2—H2C	106 (2)
O3S—Zn—O3W	90.70 (7)	H1C—C2—H2C	115 (3)
O1—Zn—O3W	163.65 (6)	C2—N—H1N	106 (2)
O2^i—Zn—O3W	89.05 (6)	C2—N—H2N	113 (3)
O1W—Zn—O3W	101.40 (7)	H1N—N—H2N	117 (3)
O3S—Zn—O2W	166.43 (7)	C2—N—H3N	101 (4)
O1—Zn—O2W	85.45 (7)	H1N—N—H3N	116 (5)
O2^i—Zn—O2W	95.96 (7)	H2N—N—H3N	102 (6)
O1W—Zn—O2W	83.64 (7)	Zn—O1W—H1W1	110 (3)
O3W—Zn—O2W	85.50 (6)	Zn—O1W—H2W1	108 (4)
O1S—S—O2S	111.00 (11)	H1W1—O1W—H2W1	113 (5)
O1S—S—O3S	109.29 (11)	Zn—O2W—H1W2	107 (3)
O2S—S—O3S	110.28 (10)	Zn—O2W—H2W2	118 (3)
O1S—S—O4S	110.34 (10)	H1W2—O2W—H2W2	112 (4)
O2S—S—O4S	109.94 (10)	Zn—O3W—H1W3	109 (3)
O3S—S—O4S	105.87 (10)	Zn—O3W—H2W3	100 (3)
O2—C1—O1	124.95 (17)	H1W3—O3W—H2W3	96 (4)
O2—C1—C2	117.30 (16)

Symmetry code: (i) x−1/2, −y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N—H1N···O3W^ii	0.95 (4)	2.00 (4)	2.929 (3)	164 (3)
N—H2N···O4S^iii	0.88 (5)	2.11 (5)	2.967 (3)	165 (4)
N—H3N···O2W^iv	0.75 (6)	2.49 (6)	3.151 (3)	148 (5)
O1W—H1W1···O4S^v	0.71 (3)	2.04 (4)	2.744 (2)	171 (4)
O1W—H2W1···O4S^vi	0.72 (5)	2.12 (5)	2.815 (2)	164 (5)
O2W—H1W2···O2S^vi	0.79 (4)	2.01 (4)	2.802 (2)	177 (4)
O2W—H2W2···O2S^vii	0.85 (5)	1.88 (5)	2.714 (2)	167 (5)
O3W—H1W3···O1S^viii	0.89 (5)	1.93 (5)	2.747 (2)	152 (4)
O3W—H2W3···O1^i	0.80 (5)	1.97 (5)	2.746 (2)	164 (4)

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