Diaqua­bis(D-valinato-κ²N,O)nickel(II)

In the title complex, diaqua­bis(2-amino-3-methyl­butyrato-κ²N,O)nickel(II), [Ni(C₅H₁₀NO₂)₂(H₂O)₂], the Ni^II atom (site symmetry 2) is octa­hedrally coordinated by two N,O-bidenate valinate ions and two water mol­ecules. A network of inter­molecular hydrogen bonds links the complex mol­ecules into a two-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.012 Å
• R factor = 0.052
• wR factor = 0.141
• Data-to-parameter ratio = 13.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K
PLAT213_ALERT_2_C Atom O3      has ADP max/min Ratio .............       3.30 prolat
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.61 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.26 Ratio
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Ni1
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.06
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         12
PLAT420_ALERT_2_C D-H Without Acceptor       N1     -   H1B    ...          ?

Alert level G
REFLT03_ALERT_4_G  WARNING: Large fraction of Friedel related reflns may
                     be needed to determine absolute structure
           From the CIF: _diffrn_reflns_theta_max           26.29
           From the CIF: _reflns_number_total               1160
           Count of symmetry unique reflns          855
           Completeness (_total/calc)            135.67%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       305
           Fraction of Friedel pairs measured     0.357
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   9 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   5 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

diaquabis(2-amino-3-methylbutyrato-κ²N,O)nickel(II)

Crystal data

[Ni(C5H10NO2)2(H2O)2]	F(000) = 348
Mr = 327.02	Dx = 1.406 Mg m^−3
Monoclinic, C2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2y	Cell parameters from 770 reflections
a = 9.863 (5) Å	θ = 3.4–23.4°
b = 6.458 (3) Å	µ = 1.28 mm^−1
c = 13.007 (7) Å	T = 293 K
β = 111.199 (8)°	Block, green
V = 772.3 (7) Å^3	0.18 × 0.14 × 0.10 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	1160 independent reflections
Radiation source: fine-focus sealed tube	1014 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.065
φ and ω scans	θmax = 26.3°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −12→11
Tmin = 0.805, Tmax = 0.881	k = −8→4
2215 measured reflections	l = −16→16

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difmap and geom
R[F^2 > 2σ(F^2)] = 0.052	H-atom parameters constrained
wR(F^2) = 0.141	w = 1/[σ^2(Fo^2) + (0.0813P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max = 0.001
1160 reflections	Δρmax = 0.84 e Å^−3
89 parameters	Δρmin = −1.04 e Å^−3
1 restraint	Absolute structure: Flack (1983), 305 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.03 (4)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Ni1	0.5000	0.6778	0.5000	0.0313 (4)
O1	0.4111 (6)	0.4482 (11)	0.5639 (5)	0.0446 (16)
O2	0.4718 (5)	0.1962 (15)	0.6883 (3)	0.0484 (14)
O3	0.3762 (7)	0.8950 (13)	0.5421 (6)	0.087 (3)
H3A	0.4030	0.9390	0.6080	0.105*
H3B	0.2989	0.9416	0.4935	0.105*
N1	0.6492 (4)	0.6671 (17)	0.6606 (3)	0.0342 (11)
H1A	0.7396	0.6799	0.6597	0.041*
H1B	0.6333	0.7747	0.6988	0.041*
C1	0.4959 (7)	0.3636 (12)	0.6507 (5)	0.0350 (16)
C2	0.6393 (6)	0.4751 (11)	0.7159 (5)	0.0324 (15)
H2	0.7190	0.3856	0.7149	0.039*
C3	0.6556 (9)	0.5035 (15)	0.8356 (6)	0.053 (2)
H3	0.6499	0.3658	0.8654	0.063*
C4	0.5339 (11)	0.631 (2)	0.8470 (7)	0.085 (5)
H4A	0.4425	0.5827	0.7959	0.127*
H4B	0.5470	0.7740	0.8317	0.127*
H4C	0.5348	0.6192	0.9209	0.127*
C5	0.8047 (10)	0.5942 (18)	0.9042 (7)	0.078 (3)
H5A	0.8228	0.5744	0.9812	0.117*
H5B	0.8058	0.7396	0.8890	0.117*
H5C	0.8789	0.5254	0.8854	0.117*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0184 (5)	0.0310 (6)	0.0438 (6)	0.000	0.0106 (4)	0.000
O1	0.025 (3)	0.061 (4)	0.039 (3)	−0.021 (3)	0.001 (2)	0.002 (3)
O2	0.050 (2)	0.048 (4)	0.046 (2)	−0.020 (4)	0.0153 (18)	−0.002 (3)
O3	0.023 (3)	0.087 (6)	0.126 (7)	0.018 (4)	−0.005 (3)	−0.060 (5)
N1	0.022 (2)	0.041 (3)	0.041 (2)	−0.006 (5)	0.0122 (17)	−0.013 (5)
C1	0.031 (3)	0.041 (4)	0.038 (4)	−0.008 (3)	0.019 (3)	−0.002 (3)
C2	0.021 (3)	0.039 (4)	0.038 (3)	−0.004 (3)	0.011 (3)	−0.002 (3)
C3	0.058 (5)	0.058 (6)	0.033 (4)	−0.015 (4)	0.006 (3)	−0.004 (4)
C4	0.087 (6)	0.122 (15)	0.065 (5)	−0.020 (8)	0.052 (5)	−0.033 (7)
C5	0.067 (6)	0.098 (9)	0.046 (5)	−0.014 (5)	−0.006 (4)	−0.020 (4)

Geometric parameters (Å, º)

Ni1—O1^i	2.046 (7)	C1—C2	1.540 (9)
Ni1—O1	2.046 (7)	C2—C3	1.517 (9)
Ni1—O3	2.059 (7)	C2—H2	0.9800
Ni1—O3^i	2.059 (7)	C3—C4	1.508 (13)
Ni1—N1^i	2.076 (4)	C3—C5	1.534 (11)
Ni1—N1	2.076 (4)	C3—H3	0.9800
O1—C1	1.260 (9)	C4—H4A	0.9600
O2—C1	1.244 (11)	C4—H4B	0.9600
O3—H3A	0.8500	C4—H4C	0.9600
O3—H3B	0.8500	C5—H5A	0.9600
N1—C2	1.455 (13)	C5—H5B	0.9600
N1—H1A	0.9000	C5—H5C	0.9600
N1—H1B	0.9000
O1^i—Ni1—O1	87.1 (4)	O1—C1—C2	118.1 (6)
O1^i—Ni1—O3	169.7 (2)	O2—C1—C2	117.2 (6)
O1—Ni1—O3	90.2 (3)	N1—C2—C3	113.8 (6)
O1^i—Ni1—O3^i	90.2 (3)	N1—C2—C1	109.8 (5)
O1—Ni1—O3^i	169.7 (2)	C3—C2—C1	111.0 (5)
O3—Ni1—O3^i	94.2 (5)	N1—C2—H2	107.3
O1^i—Ni1—N1^i	79.6 (3)	C3—C2—H2	107.3
O1—Ni1—N1^i	97.6 (3)	C1—C2—H2	107.3
O3—Ni1—N1^i	91.0 (3)	C2—C3—C4	112.0 (6)
O3^i—Ni1—N1^i	91.6 (3)	C2—C3—C5	111.5 (7)
O1^i—Ni1—N1	97.6 (3)	C4—C3—C5	111.3 (8)
O1—Ni1—N1	79.6 (3)	C2—C3—H3	107.2
O3—Ni1—N1	91.6 (3)	C4—C3—H3	107.2
O3^i—Ni1—N1	91.0 (3)	C5—C3—H3	107.2
N1^i—Ni1—N1	176.2 (6)	C3—C4—H4A	109.5
C1—O1—Ni1	115.8 (5)	C3—C4—H4B	109.5
Ni1—O3—H3A	119.9	H4A—C4—H4B	109.5
Ni1—O3—H3B	120.1	C3—C4—H4C	109.5
H3A—O3—H3B	120.0	H4A—C4—H4C	109.5
C2—N1—Ni1	112.1 (5)	H4B—C4—H4C	109.5
C2—N1—H1A	109.2	C3—C5—H5A	109.5
Ni1—N1—H1A	109.2	C3—C5—H5B	109.5
C2—N1—H1B	109.2	H5A—C5—H5B	109.5
Ni1—N1—H1B	109.2	C3—C5—H5C	109.5
H1A—N1—H1B	107.9	H5A—C5—H5C	109.5
O1—C1—O2	124.7 (6)	H5B—C5—H5C	109.5

Symmetry code: (i) −x+1, y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2^ii	0.90	2.19	3.076 (7)	170
O3—H3A···O2^iii	0.85	1.95	2.644 (11)	138
O3—H3B···O1^iv	0.85	1.93	2.688 (10)	148

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