In situ single-crystal to single-crystal (SCSC) transformation of the one-dimensional polymer catena-poly[[di­aqua(sulfato)copper(II)]-μ₂-glycine] into the two-dimensional polymer poly[μ₂-glycine-μ₄-sulfato-copper(II)]

The one-dimensional coordination polymer catena-poly[di­aqua(sulfato-κO)copper(II)]-μ₂-glycine-κ²O:O′], [Cu(SO₄)(C₂H₅NO₂)(H₂O)₂]_n, (I), was synthesized by slow evaporation under vacuum of a saturated aqueous equimolar mixture of copper(II) sulfate and glycine. On heating the same blue crystal of this complex to 435 K in an oven, its aspect changed to a very pale blue and crystal structure analysis indicated that it had transformed into the two-dimensional coordination polymer poly[(μ₂-glycine-κ²O:O′)(μ₄-sulfato-κ⁴O:O′:O′′:O′′)copper(II)], [Cu(SO₄)(C₂H₅NO₂)]_n, (II). In (I), the Cu^II cation has a penta­coordinate square-pyramidal coordination environment. It is coordinated by two water mol­ecules and two O atoms of bridging glycine carboxyl­ate groups in the basal plane, and by a sulfate O atom in the apical position. In complex (II), the Cu^II cation has an octa­hedral coordination environment. It is coordinated by four sulfate O atoms, one of which bridges two Cu^II cations, and two O atoms of bridging glycine carboxyl­ate groups. In the crystal structure of (I), the one-dimensional polymers, extending along [001], are linked via N—H...O, O—H...O and bifurcated N—H...O,O hydrogen bonds, forming a three-dimensional framework. In the crystal structure of (II), the two-dimensional networks are linked via bifurcated N—H...O,O hydrogen bonds involving the sulfate O atoms, forming a three-dimensional framework. In the crystal structures of both compounds, there are C—H...O hydrogen bonds present, which reinforce the three-dimensional frameworks.

S1. Introduction

Trace minerals represent a tiny proportion of the body tissue of living organisms, but they play a major role in their metabolism. The chemical form of the trace mineral has a considerable influence on its stability towards dietary ingredients like phytic acids (Vohra et al., 1965; Zhou et al., 1992) or phenolic compounds (Cook, 1990; Hurrell, 1997). Inter­actions can occur between them to produce insoluble components which result in a decrease in absorption of the mineral. These reactions especially concern the inorganic forms of trace minerals, for example, sulfates and oxides. Organic trace mineral forms, such as chelates, proteinates, polysaccharides and complexes, can offer protection against anti-nutritional components, depending on the stability of the chemical bonding between the metal and the ligand(s). It has been shown (Wichert et al., 2002; Spears et al., 2004; Schlegel & Windisch, 2006) that the absorption of zinc(II), for example, is superior in the complexed form rather than simply using zinc(II) sulfate. The bioavailability of copper from copper glycinate in steers fed high dietary sulfur and molybdenum has also been shown to be more effective than using copper(II) sulfate (Hansen et al., 2008). The critical part of the synthesis of such compounds lies in the manufacturing process used to obtain the correct hydrated form (Jacquier & Oguey, 2003; Meunier & Oguey, 2010). Their stability towards moisture conditions is extremely important and, for practical purposes, a free-flowing powder must be obtained in order to avoid the so called `caking phenomenon'. These crystalline organic trace mineral complexes were obtained by the reaction of metal sulfates with glycine. Two zinc(II) sulfate glycine complexes, formed under vacuum (Jacquier & Oguey, 2003), are in fact the product sold as an animal feed additive under the trade name of B-TRAXIM 2C (Pancosma SA) (Oguey et al., 2008).

Recently, the equilibrium crystallization and characterization of a series of glycine metal sulfate complexes have been reported (Tepavitcharova et al., 2012). The Gly–MSO₄–H₂O systems (M = Mn^II, Fe^II, Co^II, Zn^II and Mg^II) were studied by isothermal decrease of supersaturated solutions at different temperatures. They identified a number of complexes with varying water content and described the crystal structures of three ionic complexes involving magnesium(II), cobalt(II) and zinc(II), and a one-dimensional glycine cobalt(II) sulfate complex. Herein, we report the structure of a unique penta­coordinate copper(II) sulfate complex of glycine and its solid-state transformation, by heating/dehydration, from a one-dimensional to a two-dimensional coordination polymer.

In recent years there have been a number of reports of in situ single-crystal to single-crystal (SCSC) transformations (He et al., 2014; Uchida et al., 2013; Halasz, 2010; Li et al., 2009), and the subject of SCSC [2+2] photodimerizations has been reviewed by Friscic & MacGillivray (2005). Recently, reversible SCSC [2,2]-cyclo­addition reactions have also been reported (Park et al., 2014). We have, for example, described the transformation of the ionic complex aqua­chlorido(2,2':6',2''-terpyridyl-κ³N,N',N'')copper(II) chlorido(di­thio­nato-κO)(2,2':6',2''-terpyridyl-κ³N,N',N'') cuprate(II) dihydrate into the binuclear complex (µ-di­thio­nato-κ²O:O')-bis­[chlorido(2,2':6',2''-terpyridyl-κ³N,N',N'')copper(II)] monohydrate (Schmitt et al., 2010). On heating the crystal, the coordinated water molecule of the cation was lost and the vacant site on the Cu^II cation atom was occupied by an O atom of the adjacent di­thio­nate anion.

S2. Experimental

S2.1. Synthesis and crystallization

Complex (I) was synthesized by slow evaporation of a saturated equimolar mixture of copper(II) sulfate and glycine in water under vacuum, using the technique developed by Pancosma SA (Jacquier & Oguey, 2003). A differential scanning calorimetry (DSC) measurement (Fig. S1 in the supporting information) indicated that an endothermic transformation takes place at ca 433 K. As our cryosystem did not allow us to heat the crystal on the diffractometer above 393 K, the same blue crystal used for the X-ray diffraction analysis of (I) was heated to 435 K in an oven and was found to transform into a very pale-blue crystal of (II), as shown in Fig. 1. The same transformation was also followed by variable-temperature powder X-ray diffraction (VT-PXRD), as shown in Fig. 2.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. While (I) crystallizes in the centrosymmetric monoclinic space group P2₁/c, compound (II) crystallized as a non-merohedral twin in the noncentrosymmetric monoclinic space group P2₁. Both general twinning and inversion twinning for both components were refined with the instructions TWIN -1 0 0 0 -1 0 1 0 1 -4 and BASF 0.20 (8) 0.30 (10) 0.20 (9) (SHELXL2014; Sheldrick, 2008), implying a 180° rotation about the c^* axis. These are the final refined values; the first parameter is the general twinning factor, while the second and third are the first and second component inversion twin factors, respectively. Correction for twinning reduced the R factor for the observed data [I > 2σ(I)] from 0.1237 to 0.0558. For (I), the H atoms of the water molecules and the NH₃⁺ group were located in a difference Fourier map and freely refined. For (II), the NH₃⁺ H atoms were included in calculated positions and treated as riding atoms, with N—H = 0.91 Å and with U_iso(H) = 1.2U_eq(N). In both (I) and (II), the methyl­ene H atoms were included in calculated positions and treated as riding atoms, with C—H = 0.93 Å and with U_iso(H) = 1.2U_eq(C).

S3. Results and discussion

The asymmetric unit of (I) consists of a Cu^II cation, a glycine molecule present in the zwitterion form, a sulfate anion and two water molecules (Fig. 3), and forms a one-dimensional zigzag coordination polymer (Fig. 4). Atom Cu1 is penta­coordinate and has an almost perfect square-pyramidal geometry, with a τ value of 0.06 (Addison et al., 1984; τ = 0 for a perfect square-pyramid; τ = 1 for perfect triangular-based pyramid). In the equatorial plane it is coordinated by two water molecules (atoms O1W and O2W) and two O atoms of bridging glycine carboxyl­ate groups (atoms O1 and O2), and in the apical position by a sulfate O atom (O11). Atom Cu1 is displaced by 0.1856 (2) Å from the mean plane through atoms O1W/O2W/O1/O2 [maximum deviation 0.0337 (18) Å [For which atom?]] towards sulfate O atom O11. The Cu—O(water) bonds are slightly longer than the Cu—O(carboxyl­ate) bonds (Table 2), while the apical Cu1—O11 bond is longer, at 2.2179 (17) Å. The intra-chain Cu···Cu distance is 4.7498 (6) Å, while the shortest inter-chain Cu···Cu distance is 5.6118 (7) Å.

In the crystal structure of (I), the one-dimensional polymers that propagate in the [001] direction are linked via N—H···O and O—H···O and bifurcated O—H,H···O and N—H···O,O hydrogen bonds, forming a three-dimensional framework (Fig. 5 and Table 3). There is also a C—H···O hydrogen bond present that consolidates the three-dimensional structure (Table 3).

After heating the same crystal of (I) to 435 K in an oven, it was remounted on the diffractometer and a full data set was measured at 173 K. It can be seen that the quality of the crystal was not as good as before (Fig. 1). When comparing typical diffraction images for the two crystals it is seen that, for (II), there are a significant number of powder diffraction lines present. However, the data were good enough to determine the crystal structure.

The asymmetric unit of (II) consists of a Cu^II cation, a glycine molecule present in the zwitterion form and a sulfate anion (Fig. 6). Two water molecules have been lost and the polymer chains of (I) have reorganized themselves to form a two-dimensional network (Fig. 7). The coordination sites on the Cu^II cation in (I) liberated by the water molecules are now occupied by sulfate O atoms.

One possible explanation for the transformation pathway is illustrated in Fig. 8. Comparing Figs. 8(a) and 8(b), it can be seen that the zigzag chains in (I) are now horizontal in (II). We propose that the coordinated sulfate O atom in (I), viz. O11, moves to coordinate the adjacent Cu^II cation, so forming a Cu—O—Cu bridge. This involves a twisting of the chains, resulting in a change in the intra-chain Cu1···Cu1 distance from 4.7498 (6) Å in (I) to 3.8998 (6) Å in (II). The sulfate group is then in a position where atoms O12 and O13 can coordinate and bridge two Cu^II cations of the adjacent chain, so forming a two-dimensional network. One problem that we have not, as yet, been able to explain is the change from a centrosymmetric arrangement in (I) to a noncentrosymmetric arrangement in (II).

In (II), atom Cu1 now has an o­cta­hedral coordination environment and exhibits a typical pseudo-Jahn–Teller distortion. In the equatorial plane it is coordinated by two O atoms of bridging carboxyl­ate groups, O1 and O2ⁱ [symmetry code: (i) -x, 1/2 + y, 1 - z], and two sulfate O atoms, O13ⁱ and O11, with similar bond lengths (Table 4). The axial positions are occupied by a bridging sulfate O atom (O14), with Cu—O bond lengths of 2.50 (2) Å (Table 4).

In the crystal of (II), the two-dimensional networks lying parallel to (001) are linked via bifurcated N—H,H···O and N—H···O,O hydrogen bonds, forming a three-dimensional framework (Fig. 9 and Table 5). There is also a C—H···O hydrogen bond present that consolidates the three-dimensional structure (Table 5).

A search of the Cambridge Structural Database (CSD; Version 5.35, last update May 2014; Allen, 2002) for transition metal complexes of glycine gave 400 hits. However, restricting the search to glycine (NH₂CH₂COO; with any type of C—O bond), sulfate, Mg^II and first-row transition metals indicated the presence of only 14 complexes, some of which have been reported more than once. These include a number of ionic complexes, such as tetra­aqua­bis­(glycine-O)iron(II) hexa­aqua­iron(II) bis­(sulfate) (Lindqvist & Rosenstein, 1960), one-dimensional coordination polymers, for example catena-poly[[(µ₂glycine)-sulfato­tri­aqua]­zinc(II)] (Fleck & Bohatý, 2004) and catena-poly[[bis­(µ₂-gylcinato)-hexa­aqua­disulfato]­dicobalt(II)] (Tepavitcharova et al., 2012), and a two-dimensional Mn^II coordination polymer (Weng et al., 2009). In all of these complexes the glycine molecule exists in the zwitterion form and coordinates the metal via the carboxyl­ate group, the amine group always being protonated.

Complex (I) is the only copper(II) sulfate–glycine coordination polymer to have been synthesized to date. It is isotypic with the zinc(II) complex catena-poly[[(µ₂-glycine)-di­aqua­sulfato]­zinc(II)] (Oguey et al., 2013a). These two complexes are unique, in as much as the Cu^II and Zn^II cations have five-fold coordination environments. Complex (II) is isotypic with the two-dimensional Mn^II coordination polymer mentioned above that was prepared hydro­thermally and which crystallized in the centrosymmetric space group P2₁/m.

It is inter­esting that, on studying single-crystal to single-crystal (SCSC) transformations of a number of these ionic complexes, different results were obtained. For example, on heating a crystal in a capillary on the diffractometer of the zinc(II) ionic complex tetra­aqua­bis­(glycine-O)zinc(II) hexa­aqua­zinc(II) bis­(sulfate) (Tepavitcharova et al., 2012), two successive SCSC transformations were observed. At ca 343 K it transformed into the one-dimensional polymer isotypic with (I), with a loss of eight water molecules (Oguey et al., 2013a). On continued heating at ca 393 K, two further water molecules were lost and the two-dimensional polymer isostructural with (II) was obtained (Oguey et al., 2014a). These two successive SCSC transformations have also been followed by cariable-temperature powder X-ray diffraction (see Fig. S2).

In contrast, for the magnesium(II) ionic complex (Elayaraja et al., 2007), heating a crystal in a capillary on the diffractometer resulted at ca 363 K in the loss of four water molecules and its SCSC transformation into the one-dimensional polymer catena-poly[[bis­(µ₂-gylcinato)-hexa­aqua­disulfato]­dimagnesium(II)] (Oguey et al., 2014b). Further heating gave an amorphous powder. This last structure is isostructural with the cobalt(II) (Tepavitcharova et al., 2012), the iron(II) (Oguey et al., 2013b) and the zinc(II) (Oguey et al., 2013c) analogues.

The reversibility of the SCSC transformation of (I) into (II) was examined by immersing a powder sample of (II) into water at room temperature. A clear pale-blue solution was obtained, indicating that (II) had dissolved. The aqueous solution was allowed to evaporate in air and yielded blue crystals of (I).

Related literature

For related literature, see: Addison et al. (1984); Allen (2002); Cook (1990); Elayaraja et al. (2007); Fleck & Bohatý (2004); Friscic & MacGillivray (2005); Halasz (2010); Hansen et al. (2008); He et al. (2014); Hurrell (1997); Jacquier & Oguey (2003); Li et al. (2009); Lindqvist & Rosenstein (1960); Meunier & Oguey (2010); Oguey et al. (2008, 2013a, 2013b, 2013c, 2014a, 2014b); Park et al. (2014); Schlegel & Windisch (2006); Schmitt et al. (2010); Sheldrick (2008); Spears et al. (2004); Tepavitcharova et al. (2012); Uchida et al. (2013); Vohra et al. (1965); Weng et al. (2009); Wichert et al. (2002); Zhou et al. (1992).

Computing details

For both compounds, data collection: X-AREA (Stoe & Cie, 2009); cell refinement: X-AREA (Stoe & Cie, 2009); data reduction: X-RED32 (Stoe & Cie, 2009); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008). Program(s) used to refine structure: SHELXL2014/6 (Sheldrick, 2008) for (I); SHELXL2013 (Sheldrick, 2008) for (II). For both compounds, molecular graphics: PLATON (Spek, 2009) and Mercury (Macrae et al., 2008). Software used to prepare material for publication: SHELXL2014/6 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010) for (I); SHELXL2013 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010) for (II).

Figures

	Fig. 1. Crystals and diffraction images of: (a) a blue crystal of (I); (b) a pale-blue crystal of (II); (c) a typical diffraction image for (I); (d) a typical diffraction image for (II) - notice the presence of the powder diffraction rings.
	Fig. 2. Variable-temperature powder diffractograms for the transformation of the copper glycine complex (I) to (II); the transformation takes place at ca 433 K.
	Fig. 3. A view of the asymmetric unit of (I), with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry code: (i) x, -y + 3/2, z - 1/2.]
	Fig. 4. A view, along the a axis, of the one-dimensional polymer structure of (I).
	Fig. 5. A view, along the c axis, of the crystal packing of (I). The hydrogen bonds are shown as pale-turquoise dashed lines (see Table 3 for details). C-bound H atoms have been omitted for clarity.
	Fig. 6. A view of the asymmetric unit of (II), with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) -x, y + 1/2, -z + 1; (ii) x - 1, y, z; (iii) -x + 1, y + 1/2, -z + 1.]
	Fig. 7. A view, along the a axis, of the two-dimensional polymer structure of (II). C-bound H atoms have been omitted for clarity.
	Fig. 8. A view of the possible pathway for the transformation of (a) complex (I) into (b) complex (II). [Meaning of dashed, dashed-dotted and long-dashed lines in (a)?]
	Fig. 9. A view, along the a axis, of the crystal packing of (II). The hydrogen bonds are shown as pale-turquoise dashed lines (see Table 5 for details). C-bound H atoms have been omitted for clarity.

(I) catena-Poly[diaqua(sulfato-κO)copper(II)]-µ₂-glycine-κ²O:O']

Crystal data

[Cu(SO4)(C2H5NO2)(H2O)2]	F(000) = 548
Mr = 270.70	Dx = 2.286 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.6347 (8) Å	Cell parameters from 6664 reflections
b = 12.3140 (9) Å	θ = 2.4–26.1°
c = 8.3675 (8) Å	µ = 3.06 mm^−1
β = 90.855 (8)°	T = 173 K
V = 786.57 (13) Å^3	Prism, blue
Z = 4	0.42 × 0.30 × 0.21 mm

Data collection

Stoe IPDS 2 diffractometer	1481 independent reflections
Radiation source: fine-focus sealed tube	1352 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.027
ϕ + ω scans	θmax = 25.6°, θmin = 2.7°
Absorption correction: multi-scan (MULABS in PLATON; Spek, 2009)	h = −9→9
Tmin = 0.850, Tmax = 1.000	k = −14→14
5320 measured reflections	l = −9→10

Refinement

Refinement on F^2	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.023	w = 1/[σ^2(Fo^2) + (0.0304P)^2 + 0.3965P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.055	(Δ/σ)max = 0.001
S = 1.13	Δρmax = 0.76 e Å^−3
1481 reflections	Δρmin = −0.33 e Å^−3
147 parameters	Extinction correction: SHELXL2014/6 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0046 (8)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq
Cu1	0.28498 (3)	0.84131 (2)	0.35769 (3)	0.00946 (12)
O1W	0.5449 (2)	0.82336 (15)	0.3700 (2)	0.0136 (4)
H1WA	0.579 (4)	0.824 (2)	0.456 (4)	0.018 (8)*
H1WB	0.585 (4)	0.773 (3)	0.321 (4)	0.023 (8)*
O2W	0.0255 (2)	0.83224 (15)	0.3800 (2)	0.0130 (3)
H2WA	−0.022 (5)	0.771 (3)	0.387 (4)	0.036 (10)*
H2WB	−0.007 (4)	0.864 (3)	0.465 (4)	0.025 (8)*
O1	0.3000 (2)	0.91826 (12)	0.56027 (19)	0.0107 (3)
O2	0.2793 (2)	0.75656 (13)	0.6748 (2)	0.0121 (3)
N1	0.2361 (3)	1.03136 (17)	0.8164 (3)	0.0140 (4)
H1A	0.314 (4)	1.061 (2)	0.755 (4)	0.012 (7)*
H1B	0.138 (4)	1.030 (3)	0.764 (4)	0.023 (8)*
H1C	0.213 (4)	1.064 (3)	0.908 (4)	0.022 (8)*
C1	0.2875 (3)	0.85914 (19)	0.6815 (3)	0.0109 (5)
C2	0.2819 (3)	0.91600 (19)	0.8415 (3)	0.0126 (5)
H2A	0.1937	0.8810	0.9100	0.015*
H2B	0.3976	0.9105	0.8960	0.015*
S1	0.21315 (7)	1.09071 (4)	0.24529 (7)	0.00928 (15)
O11	0.3070 (2)	0.98928 (13)	0.2082 (2)	0.0148 (4)
O12	0.1499 (2)	1.13996 (13)	0.0921 (2)	0.0143 (4)
O13	0.0632 (2)	1.06845 (14)	0.3485 (2)	0.0144 (4)
O14	0.3330 (2)	1.16977 (13)	0.3236 (2)	0.0147 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.01192 (16)	0.00816 (17)	0.00830 (17)	−0.00001 (10)	0.00031 (10)	−0.00131 (11)
O1W	0.0151 (8)	0.0130 (9)	0.0127 (10)	0.0021 (7)	−0.0006 (7)	−0.0032 (8)
O2W	0.0150 (8)	0.0104 (8)	0.0137 (9)	−0.0024 (7)	0.0012 (7)	−0.0033 (7)
O1	0.0135 (8)	0.0097 (8)	0.0089 (8)	0.0000 (6)	0.0002 (6)	0.0017 (6)
O2	0.0171 (8)	0.0089 (8)	0.0102 (8)	0.0005 (6)	−0.0010 (6)	0.0002 (6)
N1	0.0193 (11)	0.0119 (11)	0.0109 (11)	−0.0001 (8)	0.0023 (9)	−0.0022 (9)
C1	0.0088 (10)	0.0133 (12)	0.0106 (12)	0.0010 (8)	−0.0003 (8)	0.0003 (9)
C2	0.0175 (11)	0.0117 (11)	0.0086 (12)	0.0007 (9)	0.0002 (9)	−0.0003 (9)
S1	0.0117 (3)	0.0076 (3)	0.0085 (3)	0.0002 (2)	0.0006 (2)	0.0003 (2)
O11	0.0203 (8)	0.0096 (8)	0.0147 (9)	0.0034 (6)	0.0053 (7)	0.0020 (7)
O12	0.0210 (9)	0.0124 (8)	0.0095 (8)	0.0038 (7)	−0.0023 (7)	0.0003 (7)
O13	0.0132 (8)	0.0157 (9)	0.0144 (9)	−0.0021 (6)	0.0029 (6)	−0.0013 (7)
O14	0.0170 (8)	0.0132 (8)	0.0139 (9)	−0.0050 (6)	−0.0012 (7)	0.0005 (7)

Geometric parameters (Å, º)

Cu1—O1	1.9438 (17)	N1—C2	1.477 (3)
Cu1—O2^i	1.9477 (17)	N1—H1A	0.87 (3)
Cu1—O1W	1.9979 (17)	N1—H1B	0.86 (4)
Cu1—O2W	1.9960 (17)	N1—H1C	0.88 (4)
Cu1—O11	2.2179 (17)	C1—C2	1.512 (3)
O1W—H1WA	0.76 (4)	C2—H2A	0.9900
O1W—H1WB	0.80 (4)	C2—H2B	0.9900
O2—C1	1.266 (3)	S1—O13	1.4699 (17)
O2—Cu1^ii	1.9477 (17)	S1—O11	1.4752 (17)
O2W—H2WA	0.83 (4)	S1—O14	1.4820 (17)
O2W—H2WB	0.85 (4)	S1—O12	1.4921 (17)
O1—C1	1.253 (3)
O1—Cu1—O2^i	170.76 (7)	H1A—N1—H1B	108 (3)
O1—Cu1—O2W	89.52 (7)	C2—N1—H1C	111 (2)
O2^i—Cu1—O2W	91.61 (7)	H1A—N1—H1C	118 (3)
O1—Cu1—O1W	87.88 (7)	H1B—N1—H1C	105 (3)
O2^i—Cu1—O1W	89.02 (8)	O1—C1—O2	123.2 (2)
O2W—Cu1—O1W	167.31 (7)	O1—C1—C2	116.8 (2)
O1—Cu1—O11	95.01 (6)	O2—C1—C2	119.9 (2)
O2^i—Cu1—O11	93.80 (7)	N1—C2—C1	109.23 (19)
O2W—Cu1—O11	100.51 (7)	N1—C2—H2A	109.8
O1W—Cu1—O11	92.10 (7)	C1—C2—H2A	109.8
Cu1—O1W—H1WA	112 (2)	N1—C2—H2B	109.8
Cu1—O1W—H1WB	117 (2)	C1—C2—H2B	109.8
H1WA—O1W—H1WB	111 (3)	H2A—C2—H2B	108.3
C1—O2—Cu1^ii	125.60 (15)	O13—S1—O11	110.52 (10)
Cu1—O2W—H2WA	119 (2)	O13—S1—O14	110.12 (10)
Cu1—O2W—H2WB	111 (2)	O11—S1—O14	110.53 (10)
H2WA—O2W—H2WB	103 (3)	O13—S1—O12	109.62 (10)
C1—O1—Cu1	114.73 (14)	O11—S1—O12	108.38 (10)
C2—N1—H1A	108.9 (19)	O14—S1—O12	107.61 (10)
C2—N1—H1B	105 (2)	S1—O11—Cu1	122.40 (10)
Cu1—O1—C1—O2	5.2 (3)	O2—C1—C2—N1	−161.8 (2)
Cu1—O1—C1—C2	−174.63 (15)	O13—S1—O11—Cu1	−20.93 (15)
Cu1^ii—O2—C1—O1	173.00 (16)	O14—S1—O11—Cu1	101.23 (12)
Cu1^ii—O2—C1—C2	−7.1 (3)	O12—S1—O11—Cu1	−141.07 (11)
O1—C1—C2—N1	18.0 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1W^iii	0.87 (3)	2.08 (3)	2.917 (3)	161 (3)
N1—H1B···O2W^iv	0.86 (4)	2.42 (3)	3.068 (3)	133 (3)
N1—H1B···O13^iv	0.86 (4)	2.16 (3)	2.923 (3)	147 (3)
N1—H1C···O12^v	0.88 (4)	1.87 (4)	2.754 (3)	175 (3)
O1W—H1WA···O14^iii	0.76 (4)	1.96 (4)	2.716 (3)	179 (3)
O1W—H1WB···O14^vi	0.80 (4)	1.87 (4)	2.667 (3)	170 (3)
O2W—H2WA···O12^vii	0.83 (4)	1.90 (4)	2.732 (2)	174 (3)
O2W—H2WB···O13^iv	0.85 (4)	1.82 (4)	2.676 (2)	177 (3)
C2—H2A···O12^iv	0.99	2.64	3.422 (3)	137

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

(II) Poly[(µ₂-glycine-κ²O:O')(µ₄-sulfato-κ⁴O:O':O'':O'')copper(II)],

Crystal data

[Cu(SO4)(C2H5NO2)]	F(000) = 234
Mr = 234.67	Dx = 2.754 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 4.8131 (8) Å	Cell parameters from 2571 reflections
b = 7.787 (1) Å	θ = 2.6–25.9°
c = 7.9262 (11) Å	µ = 4.21 mm^−1
β = 107.729 (12)°	T = 173 K
V = 282.96 (7) Å^3	Prism, very pale blue
Z = 2	0.42 × 0.30 × 0.21 mm

Data collection

Stoe IPDS 2 diffractometer	1065 independent reflections
Radiation source: fine-focus sealed tube	862 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.110
ϕ + ω scans	θmax = 25.7°, θmin = 2.6°
Absorption correction: multi-scan (MULABS in PLATON; Spek, 2009)	h = −5→5
Tmin = 0.646, Tmax = 1.000	k = −9→9
3296 measured reflections	l = −9→9

Refinement

Refinement on F^2	1 restraint
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.056	H-atom parameters constrained
wR(F^2) = 0.132	w = 1/[σ^2(Fo^2) + (0.067P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.98	(Δ/σ)max = 0.043
1065 reflections	Δρmax = 0.82 e Å^−3
104 parameters	Δρmin = −0.71 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refined as a 4-component inversion twin.

TWIN -1 0 0 0 -1 0 1 0 1 -4 BASF 0.20187 0.30116 0.19949 (e.s.d. 0.08667 0.10598 0.08668)

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

	x	y	z	Uiso*/Ueq
Cu1	−0.0044 (16)	0.7841 (9)	0.4855 (3)	0.0239 (6)
S1	0.3739 (11)	0.5278 (11)	0.3240 (6)	0.0240 (12)
O1	0.256 (5)	0.680 (3)	0.699 (3)	0.032 (5)
O2	0.274 (5)	0.388 (3)	0.727 (3)	0.035 (6)
O11	0.199 (6)	0.693 (3)	0.329 (3)	0.031 (5)
O14	0.660 (3)	0.533 (3)	0.4498 (16)	0.028 (3)
O12	0.377 (4)	0.516 (4)	0.1411 (19)	0.030 (5)
O13	0.208 (5)	0.379 (3)	0.358 (3)	0.032 (5)
N1	0.779 (6)	0.396 (2)	0.980 (3)	0.035 (5)
H1N	0.6478	0.3636	1.0364	0.052*
H2N	0.9566	0.4117	1.0616	0.052*
H3N	0.7916	0.3123	0.9027	0.052*
C1	0.385 (4)	0.535 (5)	0.762 (2)	0.023 (4)
C2	0.682 (7)	0.557 (4)	0.883 (3)	0.027 (6)
H2A	0.8155	0.5887	0.8149	0.032*
H2B	0.6843	0.6513	0.9680	0.032*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0296 (14)	0.0212 (8)	0.0212 (11)	0.0043 (13)	0.008 (2)	0.0041 (16)
S1	0.033 (3)	0.0187 (19)	0.021 (2)	0.001 (6)	0.009 (2)	0.004 (2)
O1	0.027 (12)	0.030 (12)	0.029 (10)	0.023 (9)	−0.008 (9)	−0.004 (9)
O2	0.048 (14)	0.023 (12)	0.032 (11)	0.015 (11)	0.011 (9)	−0.003 (9)
O11	0.047 (14)	0.024 (11)	0.025 (9)	0.008 (11)	0.016 (9)	0.000 (8)
O14	0.030 (6)	0.028 (7)	0.026 (9)	−0.008 (13)	0.006 (6)	0.002 (13)
O12	0.050 (10)	0.028 (12)	0.017 (6)	−0.003 (12)	0.019 (7)	−0.006 (8)
O13	0.034 (13)	0.027 (10)	0.039 (11)	−0.006 (11)	0.017 (10)	0.004 (9)
N1	0.050 (15)	0.019 (8)	0.035 (10)	−0.004 (12)	0.012 (12)	−0.003 (7)
C1	0.035 (11)	0.022 (10)	0.015 (9)	0.016 (18)	0.013 (8)	0.001 (12)
C2	0.033 (12)	0.014 (16)	0.030 (10)	0.002 (16)	0.006 (14)	0.010 (10)

Geometric parameters (Å, º)

Cu1—O1	1.95 (2)	S1—O11	1.55 (2)
Cu1—O2^i	1.97 (2)	O1—C1	1.31 (4)
Cu1—O11	1.93 (2)	O2—C1	1.25 (4)
Cu1—O13^i	1.94 (2)	N1—C2	1.48 (3)
Cu1—O14^ii	2.50 (2)	N1—H1N	0.9100
Cu1—O14^iii	2.50 (2)	N1—H2N	0.9100
O2—Cu1^iv	1.97 (2)	N1—H3N	0.9100
O13—Cu1^iv	1.94 (2)	C1—C2	1.47 (3)
S1—O14	1.432 (13)	C2—H2A	0.9900
S1—O12	1.457 (15)	C2—H2B	0.9900
S1—O13	1.48 (2)
O11—Cu1—O13^i	179.0 (14)	C2—N1—H1N	109.5
O11—Cu1—O1	95.1 (10)	C2—N1—H2N	109.5
O13^i—Cu1—O1	85.5 (10)	H1N—N1—H2N	109.5
O11—Cu1—O2^i	86.0 (10)	C2—N1—H3N	109.5
O13^i—Cu1—O2^i	93.4 (10)	H1N—N1—H3N	109.5
O1—Cu1—O2^i	178.7 (13)	H2N—N1—H3N	109.5
O14—S1—O12	113.4 (9)	O2—C1—O1	125.4 (18)
O14—S1—O13	110.6 (13)	O2—C1—C2	121 (3)
O12—S1—O13	107.7 (14)	O1—C1—C2	114 (3)
O14—S1—O11	112.0 (15)	N1—C2—C1	109 (3)
O12—S1—O11	104.3 (13)	N1—C2—H2A	109.8
O13—S1—O11	108.6 (8)	C1—C2—H2A	109.8
C1—O1—Cu1	142.7 (17)	N1—C2—H2B	109.8
C1—O2—Cu1^iv	133.7 (16)	C1—C2—H2B	109.9
S1—O11—Cu1	134.9 (13)	H2A—C2—H2B	108.3
S1—O13—Cu1^iv	145.3 (16)
O14—S1—O11—Cu1	−76 (2)	Cu1^iv—O2—C1—O1	35 (3)
O12—S1—O11—Cu1	161 (2)	Cu1^iv—O2—C1—C2	−146 (2)
O13—S1—O11—Cu1	46 (2)	Cu1—O1—C1—O2	−38 (4)
O14—S1—O13—Cu1^iv	73 (3)	Cu1—O1—C1—C2	142 (3)
O12—S1—O13—Cu1^iv	−163 (2)	O2—C1—C2—N1	−14 (3)
O11—S1—O13—Cu1^iv	−51 (3)	O1—C1—C2—N1	166 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1^v	0.91	2.47	3.10 (3)	127
N1—H1N···O12^vi	0.91	2.11	2.78 (3)	130
N1—H2N···O12^vii	0.91	2.09	2.92 (3)	152
N1—H2N···O13^vii	0.91	2.31	3.08 (3)	143
N1—H3N···O11^viii	0.91	2.07	2.94 (3)	161
N1—H3N···O12^viii	0.91	2.44	3.13 (3)	133
C2—H2A···O1^ix	0.99	2.65	3.62 (4)	168
C2—H2A···O13^iii	0.99	2.63	3.29 (4)	124

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