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The crystal structures are reported of trans-dioxocyclam dihydrate, C10H20N4O2·2H2O, a structural isomer of the well known cis-dioxocyclam, and of its novel Ni complex, (1,4,8,11-tetra­aza­cyclo­tetra­decane-2,9-dionato-κ4N)­nickel(II) dihydrate, [Ni(C10H18N4O2)]·2H2O, the first example of a trans­ition metal complex of this ligand. Both mol­ecules lie on crystallographic centres of inversion. The free ligand has two of its N atoms turned outwards from the ring and hydrogen bonded to water mol­ecules. A major conformational change takes place in the complex in which the ligand binds in a trans tetradentate fashion, as suggested by the electronic spectrum. The nickel(II) ion is low spin, although the electronic spectrum of the complex in water indicates an equilibrium mixture of low-spin and high-spin species. The irreversible electrochemical oxidation of [NiL1] (L1 is deprotonated trans-dioxocyclam, C10H18N4O2) in water occurs at a potential of 0.964 V [versus SHE (standard hydrogen electrode)], which is very similar to that for the Ni–cis-dioxocyclam complex.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100020308/bm1440sup1.cif
Contains datablocks I, II, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270100020308/bm1440Isup2.hkl
Contains datablock I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270100020308/bm1440IIsup3.hkl
Contains datablock II

CCDC references: 163881; 163882

Computing details top

For both compounds, data collection: SMART (Siemens, 1994); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

(I) 1,4,8,11-tetraazacyclotetradecane-2,9-dione dihydrate top
Crystal data top
C10H20N4O2·2H2OZ = 1
Mr = 264.33F(000) = 144
Triclinic, P1Dx = 1.339 Mg m3
a = 4.869 (3) ÅMo Kα radiation, λ = 0.71073 Å
b = 7.530 (5) ÅCell parameters from 1077 reflections
c = 9.150 (5) Åθ = 3–20°
α = 83.037 (10)°µ = 0.10 mm1
β = 88.727 (15)°T = 200 K
γ = 79.806 (10)°Prism AUTHOR: please specify what kind, colourless
V = 327.7 (3) Å30.48 × 0.10 × 0.10 mm
Data collection top
Siemens SMART CCD area-detector
diffractometer
1118 independent reflections
Radiation source: normal-focus sealed tube825 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.018
Detector resolution: 8.192 pixels mm-1θmax = 25.0°, θmin = 2.2°
ω scansh = 55
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
k = 88
Tmin = 0.58, Tmax = 0.96l = 106
1627 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.046Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.118H atoms treated by a mixture of independent and constrained refinement
S = 0.97 w = 1/[σ2(Fo2) + (0.073P)2]
where P = (Fo2 + 2Fc2)/3
1118 reflections(Δ/σ)max = 0.025
102 parametersΔρmax = 0.18 e Å3
0 restraintsΔρmin = 0.24 e Å3
Special details top

Experimental. The data collection nominally covered over a hemisphere of reciprocal space, by a combination of three sets of exposures with different φ angles for the crystal; each 10 s exposure covered 0.3° in ω. The crystal-to-detector distance was 5.0 cm. Coverage of the unique set is over 97% complete to at least 26° in θ. Crystal decay was found to be negligible by by repeating the initial frames at the end of data collection and analyzing the duplicate reflections.

The program SADABS (Sheldrick, 1996) can correct for factors other than absorption, including for any time-dependent changes: among other possible factors might be crystal incompletely bathed in the X-ray beam; formation of ice; severe absorption caused by oblique inclination of the beam and the fibre. Although no particular factor has been identified as being responsible for the discrepant range of transmission coefficients in the present case, it is clear that some factors or factors other than absorption were affecting the data, and refinement using the corrected data was more valid than that using the uncorrected set. Our estimate of the transmission coefficient range actually due to absorption would be of the order of 0.85–0.96.

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. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating _R_factor_obs 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)
O10.5423 (3)0.2685 (2)0.44403 (15)0.0340 (4)
C10.3047 (4)0.2498 (3)0.4106 (2)0.0238 (5)
N20.1230 (4)0.1947 (2)0.51042 (19)0.0254 (4)
H20.054 (5)0.202 (3)0.479 (3)0.036 (6)*
C30.1882 (4)0.1570 (3)0.6668 (2)0.0271 (5)
H3A0.39120.11290.67930.033*
H3B0.08980.05960.71180.033*
C40.1038 (4)0.3241 (3)0.7458 (2)0.0269 (5)
H4A0.18680.30050.84560.032*
H4B0.17820.42730.69150.032*
N50.2007 (4)0.3733 (2)0.7581 (2)0.0251 (4)
H5A0.274 (4)0.384 (3)0.672 (2)0.028 (6)*
C60.2931 (4)0.5413 (3)0.8254 (2)0.0261 (5)
H6A0.22020.52230.92730.031*
H6B0.49930.56180.83190.031*
C70.2066 (4)0.7140 (3)0.7471 (2)0.0268 (5)
H7A0.28680.81850.79980.032*
H7B0.00090.70130.74950.032*
O20.2756 (5)0.0943 (3)0.9866 (2)0.0480 (5)
H2A0.291 (6)0.173 (4)0.909 (3)0.064 (9)*
H2B0.43 (2)0.059 (13)0.988 (12)0.15 (5)*0.50
H2C0.120 (9)0.033 (6)1.002 (5)0.030 (14)*0.50
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0201 (8)0.0440 (9)0.0370 (9)0.0073 (6)0.0037 (6)0.0017 (7)
C10.0202 (11)0.0197 (10)0.0297 (12)0.0012 (8)0.0000 (8)0.0024 (9)
N20.0221 (9)0.0266 (10)0.0276 (10)0.0052 (7)0.0010 (7)0.0023 (7)
C30.0274 (11)0.0236 (11)0.0287 (12)0.0028 (9)0.0005 (9)0.0012 (9)
C40.0244 (11)0.0281 (11)0.0279 (12)0.0055 (8)0.0023 (8)0.0005 (9)
N50.0241 (9)0.0261 (10)0.0253 (10)0.0056 (7)0.0012 (7)0.0014 (8)
C60.0238 (11)0.0299 (11)0.0241 (11)0.0036 (9)0.0023 (8)0.0033 (9)
C70.0268 (11)0.0239 (11)0.0301 (12)0.0033 (8)0.0015 (9)0.0066 (9)
O20.0498 (14)0.0418 (11)0.0459 (12)0.0043 (10)0.0047 (10)0.0144 (9)
Geometric parameters (Å, º) top
O1—C11.239 (2)C6—C71.528 (3)
C1—N21.339 (3)C7—C1i1.507 (3)
C1—C7i1.507 (3)N2—H2A0.905 (10)
N2—C31.456 (3)N5—H5A0.864 (10)
C3—C41.516 (3)O2—H2A0.86 (1)
C4—N51.469 (3)O2—H2B0.85 (2)
N5—C61.469 (3)O2—H2C0.82 (2)
O1—C1—N2122.49 (19)N5—C4—C3111.71 (16)
O1—C1—C7i121.17 (18)C4—N5—C6113.66 (15)
N2—C1—C7i116.33 (17)N5—C6—C7116.61 (16)
C1—N2—C3122.27 (18)C1i—C7—C6111.41 (16)
N2—C3—C4111.94 (16)
Symmetry code: (i) x, y+1, z+1.
(II) (1,4,8,11-tetraazacyclotetradecane-2,9-dione-κ4N)nickel(II) dihydrate top
Crystal data top
[Ni(C10H18N4O2)]·2H2OF(000) = 680
Mr = 321.03Dx = 1.565 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 20.861 (3) ÅCell parameters from 1275 reflections
b = 7.3385 (10) Åθ = 3–20°
c = 9.6130 (13) ŵ = 1.44 mm1
β = 112.205 (2)°T = 180 K
V = 1362.5 (3) Å3Plate, red
Z = 40.40 × 0.15 × 0.04 mm
Data collection top
Siemens SMART CCD area-detector
diffractometer
1193 independent reflections
Radiation source: normal-focus sealed tube799 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.073
Detector resolution: 8.192 pixels mm-1θmax = 25.0°, θmin = 3.0°
ω scansh = 2424
Absorption correction: ψ-scan
(SADABS; Sheldrick, 1996)
k = 68
Tmin = 0.67, Tmax = 0.96l = 1111
3255 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.060Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.153H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.079P)2]
where P = (Fo2 + 2Fc2)/3
1193 reflections(Δ/σ)max = 0.025
91 parametersΔρmax = 0.90 e Å3
0 restraintsΔρmin = 0.53 e Å3
Special details top

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

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Ni11/41/400.0239 (4)
O10.1331 (2)0.6724 (6)0.0596 (5)0.0422 (12)
C10.2651 (3)0.5716 (9)0.1724 (7)0.0339 (16)
H1A0.25640.70340.15180.041*
H1B0.26330.54440.27170.041*
N20.2128 (2)0.4618 (7)0.0531 (5)0.0296 (12)
C30.1502 (3)0.5278 (10)0.0070 (7)0.0350 (16)
C40.0935 (3)0.4286 (10)0.1181 (8)0.0477 (19)
H4A0.04900.45290.10690.057*
H4B0.09030.48240.21500.057*
C50.1009 (3)0.2303 (10)0.1273 (8)0.0399 (17)
H5A0.10000.17400.03440.048*
H5B0.06060.18300.21270.048*
N60.1635 (3)0.1744 (8)0.1461 (6)0.0318 (13)
H6A0.169 (3)0.230 (9)0.220 (7)0.038*
C70.1670 (3)0.0209 (9)0.1706 (7)0.0397 (17)
H7A0.13020.05520.26740.048*
H7B0.15890.08860.08960.048*
O20.0083 (2)0.8499 (6)0.0915 (5)0.0465 (13)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ni10.0207 (6)0.0223 (6)0.0244 (6)0.0015 (6)0.0037 (4)0.0033 (6)
O10.038 (3)0.031 (3)0.047 (3)0.014 (2)0.005 (2)0.009 (2)
C10.024 (3)0.026 (4)0.044 (4)0.005 (3)0.004 (3)0.005 (3)
N20.025 (3)0.028 (3)0.031 (3)0.000 (2)0.005 (2)0.002 (2)
C30.030 (4)0.040 (4)0.033 (3)0.001 (3)0.010 (3)0.001 (3)
C40.033 (4)0.051 (5)0.050 (4)0.012 (4)0.005 (3)0.011 (4)
C50.023 (3)0.036 (5)0.058 (4)0.003 (3)0.011 (3)0.011 (4)
N60.026 (3)0.032 (3)0.033 (3)0.002 (2)0.006 (2)0.005 (3)
C70.032 (4)0.029 (4)0.050 (4)0.007 (3)0.006 (3)0.010 (3)
O20.044 (3)0.034 (3)0.053 (3)0.012 (2)0.009 (2)0.000 (2)
Geometric parameters (Å, º) top
Ni1—N2i1.892 (5)N2—C31.303 (7)
Ni1—N21.892 (5)C3—C41.517 (9)
Ni1—N6i1.902 (5)C4—C51.470 (9)
Ni1—N61.902 (5)C5—N61.444 (8)
O1—C31.282 (7)N6—C71.458 (8)
C1—C7i1.470 (8)C7—C1i1.470 (8)
C1—N21.487 (7)N6—H6A0.864 (10)
N2i—Ni1—N2180O1—C3—N2124.4 (6)
N2i—Ni1—N6i93.9 (2)O1—C3—C4117.4 (5)
N2—Ni1—N6i86.1 (2)N2—C3—C4118.2 (6)
N2i—Ni1—N686.1 (2)C5—C4—C3117.0 (6)
N2—Ni1—N693.9 (2)N6—C5—C4114.2 (6)
N6i—Ni1—N6180C5—N6—C7113.7 (5)
C7i—C1—N2106.4 (5)C5—N6—Ni1118.3 (4)
C3—N2—C1114.2 (5)C7—N6—Ni1108.3 (4)
C3—N2—Ni1132.4 (4)N6—C7—C1i110.9 (5)
C1—N2—Ni1113.4 (3)
Symmetry code: (i) x+1/2, y+1/2, z.
 

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