Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807056437/ng2364sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807056437/ng2364Isup2.hkl |
CCDC reference: 672647
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.007 Å
- H-atom completeness 78%
- Disorder in main residue
- R factor = 0.054
- wR factor = 0.133
- Data-to-parameter ratio = 15.0
checkCIF/PLATON results
No syntax errors found
Alert level B PLAT220_ALERT_2_B Large Non-Solvent C Ueq(max)/Ueq(min) ... 4.39 Ratio PLAT222_ALERT_3_B Large Non-Solvent H Ueq(max)/Ueq(min) ... 4.05 Ratio
Alert level C CHEMW03_ALERT_2_C The ratio of given/expected molecular weight as calculated from the _atom_site* data lies outside the range 0.99 <> 1.01 From the CIF: _cell_formula_units_Z 4 From the CIF: _chemical_formula_weight 788.56 TEST: Calculate formula weight from _atom_site_* atom mass num sum C 12.01 20.00 240.22 H 1.01 28.00 28.22 N 14.01 2.00 28.01 O 16.00 18.00 287.98 K 39.10 2.00 78.20 Co 58.93 2.00 117.87 Calculated formula weight 780.50 PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ? PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ? PLAT043_ALERT_1_C Check Reported Molecular Weight ................ 788.56 PLAT044_ALERT_1_C Calculated and Reported Dx Differ .............. ? PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............ 2.00 Ratio PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)... ? PLAT153_ALERT_1_C The su's on the Cell Axes are Equal (x 100000) 500 Ang. PLAT220_ALERT_2_C Large Non-Solvent O Ueq(max)/Ueq(min) ... 2.91 Ratio PLAT301_ALERT_3_C Main Residue Disorder ......................... 14.00 Perc. PLAT341_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ... 7
Alert level G FORMU01_ALERT_1_G There is a discrepancy between the atom counts in the _chemical_formula_sum and _chemical_formula_moiety. This is usually due to the moiety formula being in the wrong format. Atom count from _chemical_formula_sum: C20 H36 Co2 K2 N2 O18 Atom count from _chemical_formula_moiety:C20 H36 Co1 K2 N2 O18 FORMU01_ALERT_2_G There is a discrepancy between the atom counts in the _chemical_formula_sum and the formula from the _atom_site* data. Atom count from _chemical_formula_sum:C20 H36 Co2 K2 N2 O18 Atom count from the _atom_site data: C20 H28 Co2 K2 N2 O18 CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected. CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional? From the CIF: _cell_formula_units_Z 4 From the CIF: _chemical_formula_sum C20 H36 Co2 K2 N2 O18 TEST: Compare cell contents of formula and atom_site data atom Z*formula cif sites diff C 80.00 80.00 0.00 H 144.00 112.00 32.00 Co 8.00 8.00 0.00 K 8.00 8.00 0.00 N 8.00 8.00 0.00 O 72.00 72.00 0.00 PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 33
0 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 11 ALERT level C = Check and explain 6 ALERT level G = General alerts; check 11 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 4 ALERT type 2 Indicator that the structure model may be wrong or deficient 4 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
K2[Co(d,l-lda)(µ-OH)]2.2H2O, was prepared by the method similar to that used for Cs2[Co(nta)(µ-OH)]2.2H2O [Visser et al., 1997]. CoCl2.6H2O (2 g, 0.008 mol) and N,N-bis(carboxymethyl) d,l-leucinate (2.08 g, 0.008 mol) was added to a KHCO3 solution (5 g, 0.05 mol) and heated on a water bath. The pH of the solution was adjusted to 6 - 7 and this solution was placed on an ice bath. H2O2 (1 cm3, 30%) was added to the solution and after a few hours a bluish violate precipitate separated out from the solution. The precipitate was filtered and dried. Re-crystallization was carried out in water and blue/purple crystals, suitable for X-ray crystallography, were obtained after a few days. yield: 63.9%. IR ν(COOH 1625 cm-1. UV-Vis λmax304, 400, 565 nm. 1H NMR (D2O, p.p.m.): 0.95 (d, 6H), 1.65 (m, 1H), 1.90 (m, 2H), 3.56 (d, 1H), 3.85 (d, 1H), 3.82(d, 1H), 4.44 (d, 1H), 4.44 (t, 1H).
The methine, methylene and methyl H atoms were placed in geometrically idealized positions (C—H = 0.93–0.98) and constrained to ride on their parent atoms with Uiso(H) = 1.2Ueq(C) for methine and methylene, and Uiso(H) = 1.5Ueq(C) for methyl respectively. Methyl torsion angles were refined from electron density. Bridging hydroxo H atoms were located from a Fourier difference map and constrained to ride on their parent atoms with Uiso(H) = 1.2Ueq(O). These show a 50% disorder due to molecules being situated on special positions in the unit cell. The isopropyl substituents are also 50% disordered for the same reason and also show high thermal vibrations on the periphery. Possible hydogen coordinates from the Fourier difference map could not be refined satisfactory for the water solvate.
Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
K2[Co2(C10H13NO6)2(OH)2] | F(000) = 1624 |
Mr = 788.56 | Dx = 1.69 Mg m−3 |
Orthorhombic, Cmca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2bc 2 | Cell parameters from 1747 reflections |
a = 12.968 (5) Å | θ = 2.7–28.1° |
b = 25.868 (5) Å | µ = 1.42 mm−1 |
c = 9.240 (5) Å | T = 293 K |
V = 3100 (2) Å3 | Plate, purple |
Z = 4 | 0.25 × 0.19 × 0.02 mm |
Bruker Kappa APEXII diffractometer | 2015 independent reflections |
Graphite monochromator | 1700 reflections with I > 2σ(I) |
Detector resolution: 512 pixels mm-1 | Rint = 0.060 |
ϕ and ω scans | θmax = 28.4°, θmin = 2.8° |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | h = −15→17 |
Tmin = 0.722, Tmax = 0.969 | k = −30→34 |
8534 measured reflections | l = −10→12 |
Refinement on F2 | 33 restraints |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.054 | w = 1/[σ2(Fo2) + (0.0203P)2 + 25.1765P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.133 | (Δ/σ)max < 0.001 |
S = 1.24 | Δρmax = 0.63 e Å−3 |
2015 reflections | Δρmin = −0.66 e Å−3 |
134 parameters |
K2[Co2(C10H13NO6)2(OH)2] | V = 3100 (2) Å3 |
Mr = 788.56 | Z = 4 |
Orthorhombic, Cmca | Mo Kα radiation |
a = 12.968 (5) Å | µ = 1.42 mm−1 |
b = 25.868 (5) Å | T = 293 K |
c = 9.240 (5) Å | 0.25 × 0.19 × 0.02 mm |
Bruker Kappa APEXII diffractometer | 2015 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2004) | 1700 reflections with I > 2σ(I) |
Tmin = 0.722, Tmax = 0.969 | Rint = 0.060 |
8534 measured reflections |
R[F2 > 2σ(F2)] = 0.054 | 33 restraints |
wR(F2) = 0.133 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.24 | w = 1/[σ2(Fo2) + (0.0203P)2 + 25.1765P] where P = (Fo2 + 2Fc2)/3 |
2015 reflections | Δρmax = 0.63 e Å−3 |
134 parameters | Δρmin = −0.66 e Å−3 |
Experimental. The intensity data was collected on a Bruker X8 Apex II 4 K Kappa CCD diffractometer using an exposure time of 20 s/frame. A total of 620 frames were collected with a frame width of 0.5° covering up to θ = 28.4° with 98.8% completeness accomplished. |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Co | 0 | 0.03898 (3) | 0.61246 (8) | 0.00824 (19) | |
C1 | 0 | 0.0787 (2) | 0.8831 (6) | 0.0122 (10) | |
C2 | 0 | 0.1258 (2) | 0.7900 (6) | 0.0165 (11) | |
H2A | −0.0604 | 0.1464 | 0.8123 | 0.02* | 0.5 |
H2B | 0.0604 | 0.1464 | 0.8123 | 0.02* | 0.5 |
C3 | −0.1807 (3) | 0.09039 (14) | 0.5868 (4) | 0.0129 (8) | |
C4 | −0.0971 (3) | 0.13099 (14) | 0.5611 (5) | 0.0174 (8) | |
H4 | −0.0817 | 0.1271 | 0.4579 | 0.021* | |
C5 | −0.1206 (6) | 0.1870 (3) | 0.5748 (10) | 0.0187 (14) | 0.5 |
H5A | −0.0584 | 0.2047 | 0.6058 | 0.022* | 0.5 |
H5B | −0.1717 | 0.1914 | 0.6505 | 0.022* | 0.5 |
C6 | −0.1607 (8) | 0.2135 (4) | 0.4365 (12) | 0.0320 (18) | 0.5 |
H6 | −0.2166 | 0.1927 | 0.395 | 0.038* | 0.5 |
C7 | −0.0754 (10) | 0.2203 (4) | 0.3234 (14) | 0.047 (3) | 0.5 |
H7A | −0.0226 | 0.2425 | 0.3615 | 0.07* | 0.5 |
H7B | −0.1039 | 0.2355 | 0.2375 | 0.07* | 0.5 |
H7C | −0.0461 | 0.1872 | 0.3004 | 0.07* | 0.5 |
C8 | −0.2027 (10) | 0.2676 (4) | 0.4777 (17) | 0.054 (3) | 0.5 |
H8A | −0.2632 | 0.2638 | 0.5365 | 0.081* | 0.5 |
H8B | −0.2198 | 0.2863 | 0.3913 | 0.081* | 0.5 |
H8C | −0.151 | 0.2862 | 0.5307 | 0.081* | 0.5 |
N | 0 | 0.11323 (16) | 0.6325 (5) | 0.0097 (9) | |
O1 | 0 | 0.03494 (14) | 0.8175 (4) | 0.0113 (8) | |
O2 | −0.1472 (2) | 0.04429 (10) | 0.6132 (3) | 0.0124 (5) | |
O3 | 0 | 0.08247 (15) | 1.0160 (4) | 0.0156 (8) | |
O4 | −0.2731 (2) | 0.10165 (11) | 0.5758 (3) | 0.0187 (6) | |
O5 | 0 | 0.03447 (14) | 0.4072 (4) | 0.0129 (8) | |
O6 | −0.3530 (2) | −0.08192 (14) | 0.7397 (4) | 0.0329 (8) | |
K | −0.33220 (9) | 0 | 0.5 | 0.0170 (3) | |
H5 | −0.057 (4) | 0.043 (4) | 0.373 (10) | 0.02* | 0.5 |
U11 | U22 | U33 | U12 | U13 | U23 | |
Co | 0.0076 (4) | 0.0083 (3) | 0.0088 (4) | 0 | 0 | 0.0003 (3) |
C1 | 0.005 (2) | 0.017 (2) | 0.015 (3) | 0 | 0 | −0.002 (2) |
C2 | 0.023 (3) | 0.013 (3) | 0.013 (3) | 0 | 0 | −0.002 (2) |
C3 | 0.0126 (19) | 0.0149 (17) | 0.0113 (18) | −0.0007 (14) | −0.0036 (15) | −0.0022 (13) |
C4 | 0.014 (2) | 0.0114 (16) | 0.027 (2) | 0.0023 (13) | −0.0090 (17) | 0.0012 (15) |
C5 | 0.011 (3) | 0.014 (2) | 0.031 (3) | 0.005 (2) | −0.006 (3) | −0.004 (3) |
C6 | 0.025 (4) | 0.024 (3) | 0.048 (4) | 0.010 (3) | −0.008 (3) | 0.013 (3) |
C7 | 0.055 (7) | 0.031 (5) | 0.054 (6) | 0.006 (5) | 0.008 (5) | 0.025 (5) |
C8 | 0.053 (7) | 0.025 (4) | 0.083 (9) | 0.021 (4) | 0.001 (6) | 0.019 (5) |
N | 0.007 (2) | 0.0090 (19) | 0.013 (2) | 0 | 0 | 0.0007 (16) |
O1 | 0.0124 (19) | 0.0118 (17) | 0.0096 (19) | 0 | 0 | 0.0002 (14) |
O2 | 0.0092 (13) | 0.0119 (12) | 0.0160 (14) | −0.0005 (9) | −0.0022 (11) | −0.0003 (11) |
O3 | 0.013 (2) | 0.023 (2) | 0.0110 (19) | 0 | 0 | −0.0016 (16) |
O4 | 0.0105 (14) | 0.0187 (14) | 0.0268 (17) | 0.0053 (10) | −0.0044 (13) | −0.0020 (12) |
O5 | 0.015 (2) | 0.0105 (17) | 0.013 (2) | 0 | 0 | 0.0004 (14) |
O6 | 0.0193 (17) | 0.055 (2) | 0.0243 (18) | 0.0144 (15) | −0.0040 (14) | −0.0127 (16) |
K | 0.0101 (6) | 0.0144 (5) | 0.0265 (7) | 0 | 0 | −0.0036 (5) |
Co—O1 | 1.897 (4) | C4—N | 1.494 (4) |
Co—O5 | 1.900 (4) | C4—H4 | 0.98 |
Co—O5i | 1.909 (4) | C5—C6 | 1.540 (13) |
Co—O2 | 1.913 (3) | C5—H5A | 0.97 |
Co—O2ii | 1.913 (3) | C5—H5B | 0.97 |
Co—N | 1.930 (4) | C6—C7 | 1.532 (16) |
Co—Coi | 2.8959 (16) | C6—C8 | 1.550 (14) |
C1—O3 | 1.232 (7) | C6—H6 | 0.98 |
C1—O1 | 1.283 (6) | C7—H7A | 0.96 |
C1—C2 | 1.491 (8) | C7—H7B | 0.96 |
C2—N | 1.491 (7) | C7—H7C | 0.96 |
C2—H2A | 0.97 | C8—H8A | 0.96 |
C2—H2B | 0.97 | C8—H8B | 0.96 |
C3—O4 | 1.237 (5) | C8—H8C | 0.96 |
C3—O2 | 1.293 (4) | N—C4ii | 1.494 (4) |
C3—C4 | 1.528 (5) | O5—Coi | 1.909 (4) |
C4—C5 | 1.485 (8) | O5—H5 | 0.83 (2) |
O1—Co—O5 | 173.32 (16) | N—C4—H4 | 103 |
O1—Co—O5i | 92.31 (17) | C3—C4—H4 | 103 |
O5—Co—O5i | 81.01 (18) | C4—C5—C6 | 115.6 (7) |
O1—Co—O2 | 90.02 (9) | C4—C5—H5A | 108.4 |
O5—Co—O2 | 90.46 (9) | C6—C5—H5A | 108.4 |
O5i—Co—O2 | 94.12 (8) | C4—C5—H5B | 108.4 |
O1—Co—O2ii | 90.02 (9) | C6—C5—H5B | 108.4 |
O5—Co—O2ii | 90.46 (9) | H5A—C5—H5B | 107.4 |
O5i—Co—O2ii | 94.12 (8) | C7—C6—C5 | 111.9 (8) |
O2—Co—O2ii | 171.76 (16) | C7—C6—C8 | 108.5 (9) |
O1—Co—N | 87.65 (18) | C5—C6—C8 | 108.5 (9) |
O5—Co—N | 99.03 (18) | C7—C6—H6 | 109.3 |
O5i—Co—N | 179.96 (19) | C5—C6—H6 | 109.3 |
O2—Co—N | 85.88 (8) | C8—C6—H6 | 109.3 |
O2ii—Co—N | 85.88 (8) | C6—C7—H7A | 109.5 |
O1—Co—Coi | 132.70 (12) | C6—C7—H7B | 109.5 |
O5—Co—Coi | 40.62 (11) | H7A—C7—H7B | 109.5 |
O5i—Co—Coi | 40.39 (12) | C6—C7—H7C | 109.5 |
O2—Co—Coi | 93.01 (8) | H7A—C7—H7C | 109.5 |
O2ii—Co—Coi | 93.01 (8) | H7B—C7—H7C | 109.5 |
N—Co—Coi | 139.65 (14) | C6—C8—H8A | 109.5 |
O3—C1—O1 | 122.8 (5) | C6—C8—H8B | 109.5 |
O3—C1—C2 | 120.6 (5) | H8A—C8—H8B | 109.5 |
O1—C1—C2 | 116.6 (5) | C6—C8—H8C | 109.5 |
N—C2—C1 | 112.7 (4) | H8A—C8—H8C | 109.5 |
N—C2—H2A | 109.1 | H8B—C8—H8C | 109.5 |
C1—C2—H2A | 109.1 | C2—N—C4 | 111.3 (3) |
N—C2—H2B | 109.1 | C2—N—C4ii | 111.3 (3) |
C1—C2—H2B | 109.1 | C4—N—C4ii | 114.9 (5) |
H2A—C2—H2B | 107.8 | C2—N—Co | 108.1 (3) |
O4—C3—O2 | 124.0 (4) | C4—N—Co | 105.3 (2) |
O4—C3—C4 | 120.8 (3) | C4ii—N—Co | 105.3 (2) |
O2—C3—C4 | 115.1 (3) | C1—O1—Co | 115.0 (3) |
C5—C4—N | 115.8 (5) | C3—O2—Co | 113.7 (2) |
C5—C4—C3 | 120.8 (5) | Co—O5—Coi | 98.99 (18) |
N—C4—C3 | 108.6 (3) | Co—O5—H5 | 111 (7) |
C5—C4—H4 | 103 | Coi—O5—H5 | 103 (7) |
O3—C1—C2—N | 180.000 (2) | O2—Co—N—C4 | −28.9 (3) |
O1—C1—C2—N | 0.000 (2) | O2ii—Co—N—C4 | 150.7 (3) |
O4—C3—C4—C5 | 22.2 (7) | Coi—Co—N—C4 | 60.9 (3) |
O2—C3—C4—C5 | −160.9 (5) | O1—Co—N—C4ii | 119.1 (3) |
O4—C3—C4—N | 159.4 (4) | O5—Co—N—C4ii | −60.9 (3) |
O2—C3—C4—N | −23.7 (5) | O2—Co—N—C4ii | −150.7 (3) |
N—C4—C5—C6 | 137.6 (7) | O2ii—Co—N—C4ii | 28.9 (3) |
C3—C4—C5—C6 | −88.1 (8) | Coi—Co—N—C4ii | −60.9 (3) |
C4—C5—C6—C7 | −72.3 (10) | O3—C1—O1—Co | 180.0000 (10) |
C4—C5—C6—C8 | 168.1 (8) | C2—C1—O1—Co | 0.0000 (10) |
C1—C2—N—C4 | 115.2 (3) | O2—Co—O1—C1 | −85.88 (8) |
C1—C2—N—C4ii | −115.2 (3) | O2ii—Co—O1—C1 | 85.88 (8) |
C1—C2—N—Co | 0.0000 (10) | N—Co—O1—C1 | 0.0000 (10) |
C5—C4—N—C2 | 57.3 (6) | Coi—Co—O1—C1 | 180.0000 (10) |
C3—C4—N—C2 | −82.3 (4) | O4—C3—O2—Co | 176.6 (3) |
C5—C4—N—C4ii | −70.5 (7) | C4—C3—O2—Co | −0.2 (4) |
C3—C4—N—C4ii | 149.9 (3) | O1—Co—O2—C3 | 105.1 (3) |
C5—C4—N—Co | 174.2 (5) | O5—Co—O2—C3 | −81.5 (3) |
C3—C4—N—Co | 34.5 (4) | O5i—Co—O2—C3 | −162.5 (3) |
O1—Co—N—C2 | 0 | N—Co—O2—C3 | 17.5 (3) |
O5—Co—N—C2 | 180 | Coi—Co—O2—C3 | −122.1 (3) |
O2—Co—N—C2 | 90.19 (9) | O5i—Co—O5—Coi | 0 |
O2ii—Co—N—C2 | −90.19 (9) | O2—Co—O5—Coi | −94.10 (8) |
Coi—Co—N—C2 | 180.0000 (10) | O2ii—Co—O5—Coi | 94.10 (8) |
O1—Co—N—C4 | −119.1 (3) | N—Co—O5—Coi | 180 |
O5—Co—N—C4 | 60.9 (3) |
Symmetry codes: (i) −x, −y, −z+1; (ii) −x, y, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5···O6iii | 0.83 (2) | 1.98 (5) | 2.745 (4) | 153 (9) |
C4—H4···O6iii | 0.98 | 2.48 | 3.294 (6) | 140 |
Symmetry code: (iii) −x−1/2, −y, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | K2[Co2(C10H13NO6)2(OH)2] |
Mr | 788.56 |
Crystal system, space group | Orthorhombic, Cmca |
Temperature (K) | 293 |
a, b, c (Å) | 12.968 (5), 25.868 (5), 9.240 (5) |
V (Å3) | 3100 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.42 |
Crystal size (mm) | 0.25 × 0.19 × 0.02 |
Data collection | |
Diffractometer | Bruker Kappa APEXII diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2004) |
Tmin, Tmax | 0.722, 0.969 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8534, 2015, 1700 |
Rint | 0.060 |
(sin θ/λ)max (Å−1) | 0.669 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.054, 0.133, 1.24 |
No. of reflections | 2015 |
No. of parameters | 134 |
No. of restraints | 33 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
w = 1/[σ2(Fo2) + (0.0203P)2 + 25.1765P] where P = (Fo2 + 2Fc2)/3 | |
Δρmax, Δρmin (e Å−3) | 0.63, −0.66 |
Computer programs: APEX2 (Bruker, 2005), SAINT-Plus (Bruker, 2004), SAINT-Plus and XPREP (Bruker, 2004), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).
Co—O1 | 1.897 (4) | Co—O2ii | 1.913 (3) |
Co—O5 | 1.900 (4) | Co—N | 1.930 (4) |
Co—O5i | 1.909 (4) | Co—Coi | 2.8959 (16) |
Co—O2 | 1.913 (3) | ||
O1—Co—O5 | 173.32 (16) | O5i—Co—O2ii | 94.12 (8) |
O1—Co—O5i | 92.31 (17) | O2—Co—O2ii | 171.76 (16) |
O5—Co—O5i | 81.01 (18) | O1—Co—N | 87.65 (18) |
O1—Co—O2 | 90.02 (9) | O5—Co—N | 99.03 (18) |
O5—Co—O2 | 90.46 (9) | O5i—Co—N | 179.96 (19) |
O5i—Co—O2 | 94.12 (8) | O2—Co—N | 85.88 (8) |
O1—Co—O2ii | 90.02 (9) | O2ii—Co—N | 85.88 (8) |
O5—Co—O2ii | 90.46 (9) |
Symmetry codes: (i) −x, −y, −z+1; (ii) −x, y, z. |
Tripod type ligands like nitrilotriacetic acid (nta) and the very similar N,N-bis(carboxymethyl) d,l-leucinate (d,l-lda) are of special interest to us in terms of its applicability as chelation agents of heavy metal ions in industrial effluents (Novitchi et al., 2005; Choi et al., 2003). Also, the fact that these ligands imitate simple biological systems make the investigation into the coordination chemistry and kinetic behaviour of complexes with metal ions like chromium(III) and cobalt(III) quite interesting (Bocarsley et al., 1990; Visser et al., 2002; Visser et al., 2006).
The title compound (I, see Fig. 1) crystallizes in the orthorhombic space group Cmca (Z=8), resulting in Co-dimers situated around special positions in the unit cell. The two cobalt centres are octahedrally surrounded by the nitrogen and three carboxylate O atoms of the lda ligand plus the two bridging hydroxo oxygen atoms. The lda ligand forms three glycinate rings around the central metal ion. These rings can be classified into one R ring, Co—N—C(2)—C(1)—O(1) and two G rings, Co—N—C(4)—C(3)—O(2) and Co—N—C(4)i—C(3)i—O(2)i according to the notations used by Weakliem et al. (1959) (Symmetry code i = -x,y,z).
The octahedral environment around the Co(III) atoms are substantially distorted. The Co—O bond distances vary between 1.897 (4) and 1.913 (3) Å, while the Co—N bond distance is 1.930 (4) Å. All the N—Co—O bond angles deviate from 90° and range between 85.88 (8) and 99.03 (18)°.
The Co—N and Co—O bond distances correspond well with that found for [Co(nta)(µ-OH)]22- [Visser et al., 1997] The N—C, C—C and C—O bonding distances within the lda ligand correspond well with those obtained for Ca(nta).2H2O (Whitlow, 1972) and Hnta (Skrzypczak-Jankun et al., 1994). The nitrogen tetrahedron is slightly distorted with angles varying between 111.3 (3) and 114.9 (5)°.
Each potassium cation interacts with ten oxygen atoms (two water molecules and eight carboxylate O atoms from three different anions), serving as a link between the anions and generating a polymeric network. The K+ to oxygen interatomic distances vary between 2.827 (3) and 3.077 (4) Å. Further links between the anions are provided by an extensive network of hydrogen bonds (see Table 2).