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Di­aqua­bis­(L-serinato)copper(II) 0.1-hydrate at 120 K

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aDepartamento de Química, Pontificia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente 225, Gávea, 22453-999 Rio de Janeiro, RJ, Brazil, bDepartamento de Química Inorgânica, Instituto de Química, Universidade Federal do Rio de Janeiro, CP 68563, 21945-970 Rio de Janeiro, RJ, Brazil, and cDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland
*Correspondence e-mail: j.skakle@abdn.ac.uk

(Received 26 October 2005; accepted 27 October 2005; online 5 November 2005)

The title compound, [Cu(C3H6NO3)2(H2O)2]·0.1H2O, is isostructural with the nickel analogue. The octa­hedral CuII ion lies on a twofold axis, with cis chelating O,N-serine groups and trans aqua ligands. Small amounts of a solvent water molecule form hydrogen bonds to link the mol­ecules along the [010] direction, while a number of strong hydrogen bonds combine to form sheets in the (110) plane.

Comment

As part of our continuing study of Cu complexes with amino acids (Felcman & de Miranda, 1997[Felcman, J. & Miranda, J. L. de (1997). J. Braz. Chem. Soc. 8, 575-580.]; de Miranda & Felcman, 2001[Miranda, J. L. de & Felcman, J. (2001). Synth. React. Inorg. Met. Chem. 31, 873-894.]; de Miranda et al., 2002[Miranda, J. L. de, Felcman, J., Wardell, J. L. & Skakle, J. M. S. (2002). Acta Cryst. C58, m471-m474.]; Felcman et al., 2003[Felcman, J., Howie, R. A., Miranda, J. L. de, Skakle, J. M. S. & Wardell, J. L. (2003). Acta Cryst. C59, m103-m106.]), we have isolated and characterized the diaqua­bis(L-serinato)copper(II) complex, (1), from an aqueous reaction mixture containing (L)-serine (ser), guanidinoacetic acid (gaa) and CuII (1:1:1). Crystals of (1) were obtained after several months. No crystalline complex containing gaa, either alone or in a mixed complex with ser, appeared in a similar time. van der Helm & Franks (1969[Helm, D. van der & Franks, W. A. (1969). Acta Cryst. B25, 451-457.]) reported the structure of the unhydrated complex, [bis­(L-serinato)copper(II)], (2), obtained from CuII and (L)-serine in methanol containing a little water.

[Scheme 1]

Complex (1), isostructural with the analogous nickel complex, diaqua­bis(L-serinato)nickel(II) hydrate, (3), (van der Helm & Hossain, 1969[Helm, D. van der & Hossain, M. B. (1969). Acta Cryst. B25, 457-463.]), has an octa­hedrally coordinated CuII ion with cis chelating O,N-ser groups and trans aqua ligands (Fig. 1[link]). A similar cis arrangement of ser units arises in square-pyramidal (2), in which a carboxyl­ate O atom, from an adjacent mol­ecule, occupies the apical position. A distant O atom is sited 3.632 (6) Å from Cu trans to the apical ligand in (2), but this can at most be considered only a very weak inter­action. Comparison of the serine–Cu bond lengths in (2) [Cu—O 1.952 (5) and 1.970 (5) Å; Cu—N 1.975 (6) and 1.988 (6) Å] and in (1) (Table 1[link]) indicates that the weaker inter­actions occur in the higher coordinate complex, (1). The serine chelate rings in (1) have envelope conformations with flaps at the N atoms. The CuII ion and the four serine binding atoms are essentially co-planar.

Small amounts of additional water mol­ecules are present in both (1) and (3). The space group and structure of (1) are notably different from those of the unhydrated compound, (2), and although only a very small amount of water was found to be present in (1), both the hydrogen-bonding scheme (see below) and the availability of space (PLATON; Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]) confirm its presence.

The non-isolation of any gaa-containing complex from the reaction mixture probably reflects more their solubility in the reaction media than their non-formation. A number of Cu–gaa complexes have been isolated, including tetra­kis(μ-guanidinoacetic acid-κ2O:O′)bis­[nitrato-κO)copper], [Cu2(NO3)2(gaa)4], (4) (de Miranda et al., 2002[Miranda, J. L. de, Felcman, J., Wardell, J. L. & Skakle, J. M. S. (2002). Acta Cryst. C58, m471-m474.]), {aqua­[μ-(N′-carboxyl­atomethyl­guanidino)oxidoacetato](μ-guanidinoacetic acid)dicopper(II)} nitrate dihydrate, [Cu2(oag)(gaa)(H2O)]NO3·2H2O, (5) (Felcman et al., 2003[Felcman, J., Howie, R. A., Miranda, J. L. de, Skakle, J. M. S. & Wardell, J. L. (2003). Acta Cryst. C59, m103-m106.]), and [CuCl2(gaa)2] (Silva et al., 2001[Silva, M. R., Paixão, J. A., Beja, A. M. & Veiga, L. A. (2001). Acta Cryst. C57, 7-8.]]. Compounds (4) and (5) were obtained from reaction mixtures containing gaa and CuII, both in the presence and absence of another amino acid, namely aspartine. Furthermore, mixed Cu–L-serine complexes, e.g. with glycine, have been reported (D'yakon et al., 1991[D'yakon, I. A., Donu, S. V., Chapurina, L. F. & Avilov, A. S. (1991). Kristallografiya, 31, 219-221.]).

The solvent water mol­ecule forms hydrogen bonds (Table 2[link]) with the O atom of the aqua ligand in the main mol­ecule (Fig. 2[link]), leading to chains along [010]. Together with the other strong hydrogen bonds (Table 2[link]), these form sheets in the (110) plane (Fig. 2[link]).

[Figure 1]
Figure 1
The mol­ecular structure of (1), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as open circles. [Symmetry code: (i) 1 − x, y, −z.]
[Figure 2]
Figure 2
Part of the crystal structure of (1), showing the formation of sheets in the (110) plane built from N—H⋯O and O—H⋯O hydrogen bonds (dashed lines). Atoms labelled with a hash (#), asterisk (*) or plus sign (+) are at the symmetry positions ([1\over2] + x, [1\over2] + y, z), ([1\over2]x, [1\over2] + y, −z) and ([1\over2] + x, −[1\over2] + y, z), respectively. The solvent water molecule is linked to the main mol­ecule by the symmetry operation ([3\over2]x, [1\over2] + y, −z). The O3—H3⋯O2iv hydrogen bond is not visible in this orientation but forms behind atom O3.

Experimental

To a hot solution (333 K) of guanidinoacetic acid (0.3513 g, 3 mmol) and serine (0.3153, 3 mmol) in deionized water (100 ml) was slowly added a solution of copper(II) nitrate (0.7248 g, 3 mmol) in deionized water (5 ml). The reaction mixture was stirred at 333 K for 8 h, cooled slowly to 277 K, and the pH adjusted to 6.0 with KOH (3 M). The white precipitate which formed was filtered off and the filtrate was stored in a covered vessel. Thin blue plate-like crystals began to be formed after the fifth month and were collected after six months, washed with absolute ethanol and dried at 323 K.

Crystal data
  • [Cu(C3H6NO3)2(H2O)2]·0.1H2O

  • Mr = 309.55

  • Monoclinic, C 2

  • a = 7.5866 (2) Å

  • b = 8.5684 (2) Å

  • c = 8.8257 (2) Å

  • β = 102.7701 (15)°

  • V = 559.52 (2) Å3

  • Z = 2

  • Dx = 1.837 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 673 reflections

  • θ = 2.9–27.5°

  • μ = 1.99 mm−1

  • T = 120 (2) K

  • Plate, pale blue

  • 0.40 × 0.30 × 0.08 mm

Data collection
  • Bruker Nonius KappaCCD area-detector diffractometer

  • φ and ω scans

  • Absorption correction: multi-scan(SADABS; Sheldrick, 2003[Sheldrick, G. M. (2003). SADABS. Version 2.10. University of Göttingen, Germany.])Tmin = 0.666, Tmax = 0.853

  • 3347 measured reflections

  • 1220 independent reflections

  • 1214 reflections with I > 2σ(I)

  • Rint = 0.026

  • θmax = 27.5°

  • h = −7 → 9

  • k = −10 → 11

  • l = −11 → 10

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.019

  • wR(F2) = 0.053

  • S = 1.10

  • 1220 reflections

  • 81 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0104P)2 + 0.5389P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.29 e Å−3

  • Δρmin = −0.44 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), with 536 Friedel pairs

  • Flack parameter: 0.071 (12)

Table 1
Selected geometric parameters (Å, °)[link]

Cu1—O1 2.032 (2)
Cu1—N1 2.079 (2)
Cu1—O4 2.1044 (11)
O1—Cu1—O1i 91.50 (11)
O1—Cu1—N1i 172.11 (9)
O1—Cu1—N1 81.16 (7)
N1—Cu1—N1i 106.31 (13)
O1—Cu1—O4 92.65 (8)
O1—Cu1—O4i 87.95 (8)
N1—Cu1—O4i 89.99 (8)
N1—Cu1—O4 89.49 (8)
O4—Cu1—O4i 179.14 (14)
Symmetry code: (i) -x+1, y, -z.

Table 2
Hydrogen-bond geometry (Å, °)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯O2ii 0.92 2.39 3.154 (3) 141
N1—H1B⋯O1iii 0.92 2.25 3.071 (2) 149
O3—H3⋯O2iv 0.84 1.84 2.671 (2) 172
O4—H4A⋯O3v 0.82 1.90 2.701 (3) 168
O4—H4B⋯O2ii 0.81 1.94 2.747 (3) 177
O5W—H5⋯O4vi 0.82 2.18 2.807 (4) 134
Symmetry codes: (ii) [x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]; (iii) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z]; (iv) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+1]; (v) [x+{\script{1\over 2}}, y-{\script{1\over 2}}, z]; (vi) [-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z].

Systematic absences permitted C2, Cm and C2/m as possible space groups; C2 was selected and confirmed by the subsequent structure analysis. In this space group, atoms Cu1 and O5W of the low-occupancy solvent water mol­ecule (see below) lie on crystallographic twofold axes. Therefore, the asymmetric unit comprises, in addition to these two atoms, one of each of a complete serinate and aqua ligand and a single H atom of the solvent water mol­ecule. The small amount of solvent water was clearly identified from the difference map. During the structure solution, and prior to the location of the water mol­ecule, the difference map revealed two electron-density peaks close to one another, which suggested disorder of the water over two sites. However, the two positions could not be refined simultaneously and indeed, once one O atom was refined, the peak in the difference map corresponding to the `second site' disappeared. Approximate positions for the H atoms of the aqua ligand and of the low-occupancy solvent water mol­ecule were then obtained from difference maps and modified to provide acceptable O—H distances (0.81–0.82 Å) and H—O—H angles (103°). Owing to correlation with the isotropic displacement parameter, the occupancy of the solvent water mol­ecule could only be established by trial and error. The value of 0.10 finally chosen was such as to provide a reasonable value for the freely refined isotropic displacement parameter of the O atom (O5W). All other H atoms were placed in calculated positions, with X—H distances of 0.99 (CH2), 1.00 (aliphatic CH), 0.92 (NH2) or 0.84 Å (OH). The torsion angle of the OH group was also refined. All H atoms were refined, finally, with a riding model, with Uiso(H) = 1.2Ueq(C,N) or 1.5Ueq(O).

Data collection: COLLECT (Nonius, 1998[Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL-X (McArdle, 1994[McArdle, P. (1994). J. Appl. Cryst. 27, 438-439.], 2005[McArdle, P. (2005). OSCAIL-X for Windows. Crystallography Centre, Chemistry Department, NUI Galway, Ireland.]) and SHELXS97 (Sheldrick, 1990[Sheldrick, G. M. (1990). Acta Cryst. A46, 467-473.]); program(s) used to refine structure: OSCAIL-X and SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXL97 and CIFTAB. University of Göttingen, Germany.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565-565.]); software used to prepare material for publication: CIFTAB (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXL97 and CIFTAB. University of Göttingen, Germany.]).

Supporting information


Computing details top

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: OSCAIL (McArdle, 1994, 2005) and SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: OSCAIL and SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: CIFTAB (Sheldrick, 1997).

diaquabis(L-serinato)copper(II) decihydrate top
Crystal data top
[Cu(C3H6NO3)2(H2O)2]·0.1H2OF(000) = 320
Mr = 309.55Dx = 1.837 Mg m3
Monoclinic, C2Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2yCell parameters from 673 reflections
a = 7.5866 (2) Åθ = 2.9–27.5°
b = 8.5684 (2) ŵ = 1.99 mm1
c = 8.8257 (2) ÅT = 120 K
β = 102.7701 (15)°Plate, pale blue
V = 559.52 (2) Å30.40 × 0.30 × 0.08 mm
Z = 2
Data collection top
Bruker Nonius KappaCCD area-detector
diffractometer
1220 independent reflections
Radiation source: Bruker Nonius FR591 rotating anode1214 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 4.0°
φ and ω scansh = 79
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
k = 1011
Tmin = 0.666, Tmax = 0.853l = 1110
3347 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: geom and difmap
R[F2 > 2σ(F2)] = 0.019H-atom parameters constrained
wR(F2) = 0.053 w = 1/[σ2(Fo2) + (0.0104P)2 + 0.5389P]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max < 0.001
1220 reflectionsΔρmax = 0.29 e Å3
81 parametersΔρmin = 0.44 e Å3
1 restraintAbsolute structure: Flack (1983), with 536 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.071 (12)
Special details top

Experimental. Although determined using DIRAX, the cell is refined during data reduction DIRAX refs: Duisenberg AJM, J. Appl. Cryst. 1992 25 92–96 and Duisenberg AJM, Hooft RWW, Schreurs AMM, Droon J.: J. Appl. Cryst. 2000 33 893–898

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*/UeqOcc. (<1)
Cu10.50000.50000.00000.00801 (11)
O10.3839 (3)0.3345 (2)0.1111 (2)0.0070 (4)
O20.2506 (2)0.2929 (2)0.30727 (18)0.0105 (3)
O30.2453 (3)0.7763 (2)0.38982 (18)0.0150 (4)
H30.25710.78390.48640.022*
N10.3790 (3)0.6455 (3)0.1359 (3)0.0061 (5)
H1A0.45160.73040.16860.007*
H1B0.26950.68070.07940.007*
C10.3257 (3)0.3816 (3)0.2255 (3)0.0066 (4)
C20.3529 (3)0.5539 (3)0.2706 (3)0.0057 (4)
H20.46820.56090.35120.007*
C30.2045 (3)0.6195 (3)0.3435 (3)0.0107 (4)
H3A0.08710.61510.26740.013*
H3B0.19450.55580.43490.013*
O40.73885 (15)0.5018 (3)0.17483 (13)0.0081 (3)
H4A0.75190.44200.24830.012*
H4B0.74020.58670.21620.012*
O5W0.50000.947 (3)0.00000.014 (5)*0.10
H50.53561.00670.05970.020*0.10
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.01260 (16)0.00605 (17)0.00643 (17)0.0000.00435 (11)0.000
O10.0129 (9)0.0053 (9)0.0040 (8)0.0007 (7)0.0044 (7)0.0013 (7)
O20.0204 (9)0.0067 (8)0.0070 (8)0.0030 (7)0.0087 (7)0.0006 (7)
O30.0377 (11)0.0045 (8)0.0054 (8)0.0004 (7)0.0105 (7)0.0013 (7)
N10.0111 (11)0.0018 (10)0.0065 (11)0.0000 (8)0.0044 (8)0.0003 (8)
C10.0097 (10)0.0029 (11)0.0065 (11)0.0003 (9)0.0004 (9)0.0002 (9)
C20.0107 (10)0.0044 (11)0.0032 (10)0.0005 (8)0.0042 (8)0.0005 (8)
C30.0184 (12)0.0048 (10)0.0117 (11)0.0002 (9)0.0095 (9)0.0008 (9)
O40.0133 (6)0.0046 (6)0.0063 (6)0.0016 (11)0.0020 (5)0.0009 (11)
Geometric parameters (Å, º) top
Cu1—O1i2.032 (2)N1—H1A0.9200
Cu1—O12.032 (2)N1—H1B0.9200
Cu1—N12.079 (2)C1—C21.531 (4)
Cu1—N1i2.079 (2)C2—C31.522 (3)
Cu1—O4i2.1044 (11)C2—H21.0000
Cu1—O42.1044 (11)C3—H3A0.9900
O1—C11.255 (3)C3—H3B0.9900
O2—C11.267 (3)O4—H4A0.8154
O3—C31.419 (3)O4—H4B0.8126
O3—H30.8400O5W—H5i0.8209
N1—C21.474 (3)O5W—H50.8209
O1—Cu1—O1i91.50 (11)Cu1—N1—H1B110.2
O1i—Cu1—N1172.11 (9)H1A—N1—H1B108.5
O1—Cu1—N1i172.11 (9)O1—C1—O2123.2 (2)
O1—Cu1—N181.16 (7)O1—C1—C2117.9 (2)
O1i—Cu1—N1i81.16 (7)O2—C1—C2118.8 (2)
N1—Cu1—N1i106.31 (13)N1—C2—C3112.8 (2)
O1—Cu1—O492.65 (8)N1—C2—C1109.8 (2)
O1i—Cu1—O4i92.65 (8)C3—C2—C1113.3 (2)
O1i—Cu1—O487.95 (8)N1—C2—H2106.8
O1—Cu1—O4i87.95 (8)C3—C2—H2106.8
N1i—Cu1—O489.99 (8)C1—C2—H2106.8
N1—Cu1—O4i89.99 (8)O3—C3—C2109.65 (19)
N1—Cu1—O489.49 (8)O3—C3—H3A109.7
N1i—Cu1—O4i89.49 (8)C2—C3—H3A109.7
O4—Cu1—O4i179.14 (14)O3—C3—H3B109.7
C1—O1—Cu1115.53 (18)C2—C3—H3B109.7
C3—O3—H3109.5H3A—C3—H3B108.2
C2—N1—Cu1107.53 (16)Cu1—O4—H4A120.8
C2—N1—H1A110.2Cu1—O4—H4B105.1
Cu1—N1—H1A110.2H4A—O4—H4B102.5
C2—N1—H1B110.2H5i—O5W—H5103.1
O1i—Cu1—O1—C1164.3 (2)Cu1—O1—C1—C21.7 (3)
N1—Cu1—O1—C112.74 (15)Cu1—N1—C2—C3157.24 (16)
O4i—Cu1—O1—C1103.05 (19)Cu1—N1—C2—C129.8 (2)
O4—Cu1—O1—C176.33 (19)O1—C1—C2—N122.2 (3)
O1—Cu1—N1—C223.48 (14)O2—C1—C2—N1159.7 (2)
N1i—Cu1—N1—C2159.1 (2)O1—C1—C2—C3149.4 (2)
O4i—Cu1—N1—C2111.40 (17)O2—C1—C2—C332.6 (3)
O4—Cu1—N1—C269.28 (17)N1—C2—C3—O357.8 (3)
Cu1—O1—C1—O2179.65 (16)C1—C2—C3—O3176.65 (18)
Symmetry code: (i) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O2ii0.922.393.154 (3)141
N1—H1B···O1iii0.922.253.071 (2)149
O3—H3···O2iv0.841.842.671 (2)172
O4—H4A···O3v0.821.902.701 (3)168
O4—H4B···O2ii0.811.942.747 (3)177
O5W—H5···O4vi0.822.182.807 (4)134
Symmetry codes: (ii) x+1/2, y+1/2, z; (iii) x+1/2, y+1/2, z; (iv) x+1/2, y+1/2, z+1; (v) x+1/2, y1/2, z; (vi) x+3/2, y+1/2, z.
 

Acknowledgements

The authors thank CNPq and FAPERJ, Brazil, for support, and the EPSRC X-ray Crystallographic Service, University of Southampton, UK, for the data collection. In addition, we acknowledge the help and advice of J. L. Wardell.

References

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