trans-Bis­(aceto­nitrile)­tetra­aqua­cobalt(II) dinitrate at 150 K

In the title compound, [Co(CH₃CN)₂(H₂O)₄](NO₃)₂, the Co^II cations occupy crystallographic inversion centres and adopt a distorted octahedral coordination geometry, with trans-disposed aceto­nitrile ligands. Extensive hydrogen-bonding interactions between the coordinated water ligands and the nitrate counter-anions lead to the formation of a three-dimensional framework. There are substantial differences between the structure of the title compound at 150 K and the previously reported structure at 293 K.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.034
• wR factor = 0.082
• Data-to-parameter ratio = 14.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           28.04
         From the CIF: _reflns_number_total               1552
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         1643
         Completeness (_total/calc)             94.46%
          Alert C: < 95% complete


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT and SHELXTL (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2002).

Tetraaquobis(acetonitrile)cobalt(II) di-nitrate

Crystal data

[Co(C2H3N)2(H2O)4](NO3)2	F(000) = 346
Mr = 337.12	Dx = 1.648 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.7375 (15) Å	Cell parameters from 2057 reflections
b = 13.029 (3) Å	θ = 3.0–26.3°
c = 7.7605 (15) Å	µ = 1.32 mm^−1
β = 119.744 (3)°	T = 150 K
V = 679.3 (2) Å^3	Block, orange
Z = 2	0.19 × 0.17 × 0.10 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1552 independent reflections
Radiation source: normal-focus sealed tube	1345 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
ω scans	θmax = 28.0°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −9→10
Tmin = 0.712, Tmax = 0.877	k = −17→16
5625 measured reflections	l = −10→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.034	Hydrogen site location: see text
wR(F^2) = 0.082	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.041P)^2 + 0.255P] where P = (Fo^2 + 2Fc^2)/3
1552 reflections	(Δ/σ)max = 0.001
105 parameters	Δρmax = 0.42 e Å^−3
6 restraints	Δρmin = −0.23 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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

	x	y	z	Uiso*/Ueq
Co1	1.00000	0.00000	1.00000	0.0227 (1)
O1	0.1620 (2)	0.18063 (12)	0.5240 (2)	0.0331 (4)
O2	0.3414 (2)	0.16261 (11)	0.8418 (2)	0.0333 (5)
O3	0.4125 (2)	0.07731 (13)	0.6451 (2)	0.0404 (5)
N10	0.3069 (3)	0.13963 (12)	0.6714 (2)	0.0257 (5)
O1W	0.7315 (2)	0.01111 (13)	0.9988 (2)	0.0365 (5)
H1A	0.699 (4)	−0.0426 (12)	1.032 (4)	0.042 (7)*
H1B	0.631 (3)	0.029 (2)	0.893 (3)	0.064 (10)*
O2W	1.0853 (3)	0.13620 (12)	1.1495 (2)	0.0444 (6)
H2A	1.107 (5)	0.1922 (13)	1.111 (4)	0.064 (9)*
H2B	1.118 (4)	0.144 (2)	1.2683 (19)	0.059 (9)*
N1S	0.8811 (3)	0.08213 (13)	0.7293 (2)	0.0283 (5)
C2S	0.7970 (3)	0.11885 (15)	0.5773 (3)	0.0260 (6)
C3S	0.6870 (3)	0.16670 (18)	0.3825 (3)	0.0361 (7)
H3S1	0.71690	0.24030	0.39410	0.0540*
H3S2	0.72620	0.13520	0.29230	0.0540*
H3S3	0.54390	0.15680	0.32990	0.0540*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.0246 (2)	0.0221 (2)	0.0192 (2)	−0.0032 (2)	0.0091 (2)	0.0008 (1)
O1	0.0382 (8)	0.0342 (8)	0.0262 (7)	0.0115 (7)	0.0155 (7)	0.0052 (6)
O2	0.0406 (9)	0.0356 (8)	0.0247 (7)	−0.0018 (7)	0.0169 (7)	−0.0009 (6)
O3	0.0388 (9)	0.0427 (9)	0.0357 (8)	0.0146 (7)	0.0155 (7)	−0.0033 (7)
N10	0.0286 (9)	0.0219 (8)	0.0276 (9)	−0.0008 (7)	0.0146 (7)	0.0021 (7)
O1W	0.0317 (8)	0.0434 (10)	0.0344 (9)	0.0026 (7)	0.0163 (7)	0.0133 (7)
O2W	0.0758 (13)	0.0285 (8)	0.0252 (8)	−0.0151 (8)	0.0222 (9)	−0.0039 (6)
N1S	0.0295 (9)	0.0281 (9)	0.0258 (9)	−0.0024 (7)	0.0125 (7)	0.0033 (7)
C2S	0.0260 (10)	0.0246 (9)	0.0282 (11)	−0.0013 (8)	0.0141 (9)	−0.0003 (8)
C3S	0.0378 (12)	0.0360 (11)	0.0283 (11)	0.0058 (10)	0.0118 (10)	0.0087 (9)

Geometric parameters (Å, º)

Co1—O1W	2.0780 (18)	O1W—H1A	0.826 (10)
Co1—O2W	2.0423 (16)	O1W—H1B	0.835 (10)
Co1—N1S	2.1182 (15)	O2W—H2A	0.834 (10)
N10—O1	1.256 (2)	O2W—H2B	0.834 (10)
N10—O2	1.249 (2)	C3S—H3S1	0.9800
N10—O3	1.239 (3)	C3S—H3S2	0.9800
N1S—C2S	1.132 (2)	C3S—H3S3	0.9800
C2S—C3S	1.457 (3)
O1W—Co1—O2W	89.00 (8)	H1A—O1W—H1B	105 (2)
O1W—Co1—N1S	91.09 (8)	Co1—O2W—H2A	128.6 (19)
O2W—Co1—N1S	89.05 (6)	Co1—O2W—H2B	125.0 (19)
O1—N10—O2	119.18 (19)	H2A—O2W—H2B	106 (2)
O1—N10—O3	119.50 (15)	C2S—C3S—H3S1	109.5
O2—N10—O3	121.32 (16)	C2S—C3S—H3S2	109.5
Co1—N1S—C2S	171.5 (2)	H3S1—C3S—H3S2	109.5
N1S—C2S—C3S	179.2 (3)	C2S—C3S—H3S3	109.5
Co1—O1W—H1A	113.4 (18)	H3S1—C3S—H3S3	109.5
Co1—O1W—H1B	118 (2)	H3S2—C3S—H3S3	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1A···O2^i	0.826 (10)	1.953 (10)	2.769 (2)	169 (2)
O1W—H1B···O3	0.835 (10)	1.932 (10)	2.765 (2)	176 (3)
O2W—H2A···O1^ii	0.834 (10)	1.917 (10)	2.751 (2)	178 (3)
O2W—H2B···O1^iii	0.834 (10)	1.898 (11)	2.724 (2)	171 (3)

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