Bis(di-2-pyridylmethane­diol-κ³N,O,N′)copper(II) DL-tartrate

The reaction of di-2-pyridyl ketone with copper dichloride dihydrate and tartaric acid in water afforded the title compound, [Cu(C₁₁H₁₀N₂O₂)₂]C₄H₄O₆. The Cu^II atom lies on an inversion center N,O,N′-chelated by two di-2-pyridylmethane­diol ligands in a tetragonally distorted octa­hedral geometry. The tartrate anion is also located on an inversion center and has disordered hydroxyl groups, each with an occupancy factor of 0.5. The hydroxyl groups of the complex cation are hydrogen bonded to the carboxyl­ate groups of the anion, thus connecting the two building units.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• Disorder in main residue
• R factor = 0.038
• wR factor = 0.091
• Data-to-parameter ratio = 11.4

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT242_ALERT_2_B Check Low       Ueq as Compared to Neighbors for        C12

Alert level C
            Value of measurement temperature given =   293.000
            Value of melting point given =     0.000
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.85
PLAT301_ALERT_3_C Main Residue  Disorder .........................       5.00 Perc.
PLAT313_ALERT_2_C Oxygen with three covalent bonds (rare) ........         O5
PLAT313_ALERT_2_C Oxygen with three covalent bonds (rare) ........         O6
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)        100 Deg.
PLAT180_ALERT_4_C Check Cell Rounding: # of Values Ending with 0 =          3

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K
PLAT779_ALERT_4_G Suspect or Irrelevant (Bond) Angle in CIF ......       5.10 Deg.
              C13  -O5   -H13B    1.555   1.555   1.555
PLAT779_ALERT_4_G Suspect or Irrelevant (Bond) Angle in CIF ......       2.70 Deg.
              C13  -O6   -H13A    1.555   1.555   1.555
PLAT779_ALERT_4_G Suspect or Irrelevant (Bond) Angle in CIF ......       1.20 Deg.
              O6   -C13  -H13A    1.555   1.555   1.555
PLAT779_ALERT_4_G Suspect or Irrelevant (Bond) Angle in CIF ......       2.10 Deg.
              O5   -C13  -H13B    1.555   1.555   1.555

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

   3 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
   1 ALERT type 3 Indicator that the structure quality may be low
   5 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Di-2-pyridylketone (dpk) functions either as a bidentate N,N'-donor or as a tridentate N,O,N'-donor towards metal ions, depending on the reaction medium used in the synthesis of the complexes (Deveson et al., 1996), and several mononuclear and polynuclear transition metal–dpk complexes have been reported (Sommerer et al., 1993; Wang et al., 1986). The structural investigations clearly demonstrate that in each case hydration occurs across the ketone double bond in the ligand and that the resulting hydroxyl group coordinates to metal.

In the title compound, two dipyridin-2-yl-methanediol ligands, each in a tridentate fashion, are bonded to the Cu^II atom lying on an inversion center (Fig. 1). The pyridyl N atoms are strongly coordinated to the metal in the equatorial plane, while the hydroxyl groups are relatively weakly coordinated in the axial positions (Table 1). The two Cu—O(hydroxy) bonds [2.392 (2) Å], being in a trans arrangement, significantly exceed the Cu—N bond distances, a feature which can be attributed to the Jahn-Teller effect and usually manifests in d⁹ metal systems. The tartrate anion is located on an inversion center with disordered hydroxyl groups, each has an occupancy factor of 0.5. The hydroxyl groups of the complex cation as donors are involved in hydrogen bonds with the tartrate anion (Table 2).

Related literature

For backgroung on di-2-pyridylketone complexes, see: Deveson et al. (1996); Sommerer et al. (1993); Wang et al. (1986).

S2. Experimental

A mixture of di-2-pyridylketone (0.184 g, 1 mmol), CuCl₂.2H₂O (0.067 g, 0.5 mmol), tartaric acid (0.075 g, 0.5 mmol) and water (18 ml) in a 25 ml Teflon-lined stainless steel reactor was heated from 298 to 453 K in 2 h and maintained at 453 K for 72 h. After the mixture was cooled to 298 K, blue crystals of the title compound were obtained.

S3. Refinement

All H atoms were positioned geometrically. Aromatic H atoms were refined as riding atoms, with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C). The other H atoms were fixed in the refinements, with U_iso(H) = 1.2U_eq(C,O).

Computing details

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. The structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level. The hydroxyl groups (O5 and O6) of the tartrate anion are half-occupied. The disordered H atoms attached to C13 have been omitted. [Symmetry codes: (i) 2 - x, -y, -z; (ii) 1 - x, 1 - y, 1 - z.]

Bis(di-2-pyridylmethanediol-κ³N,O,N')copper(II) tartrate

Crystal data

[Cu(C11H10N2O2)2]C4H4O6	Z = 1
Mr = 616.03	F(000) = 317
Triclinic, P1	Dx = 1.602 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.7893 (8) Å	Cell parameters from 1352 reflections
b = 8.1068 (8) Å	θ = 2.8–26.5°
c = 11.3136 (12) Å	µ = 0.92 mm^−1
α = 105.973 (1)°	T = 293 K
β = 90.431 (1)°	Prism, blue
γ = 110.584 (1)°	0.45 × 0.30 × 0.18 mm
V = 638.65 (11) Å^3

Data collection

Bruker SMART APEX CCD area-detector diffractometer	2235 independent reflections
Radiation source: fine-focus sealed tube	1978 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.015
ϕ and ω scans	θmax = 25.1°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.726, Tmax = 0.850	k = −9→8
3231 measured reflections	l = −13→11

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.091	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0346P)^2 + 0.5737P] where P = (Fo^2 + 2Fc^2)/3
2235 reflections	(Δ/σ)max < 0.001
196 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.31 e Å^−3

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.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cu1	1.0000	0.0000	0.0000	0.03430 (17)
N1	0.9447 (3)	0.0410 (3)	0.1761 (2)	0.0337 (5)
N2	0.8085 (3)	0.1020 (3)	−0.0329 (2)	0.0357 (5)
O1	1.1369 (3)	0.3273 (3)	0.09003 (17)	0.0394 (5)
H1A	1.2267	0.3677	0.1473	0.047*
O2	1.0017 (3)	0.5166 (3)	0.21831 (19)	0.0488 (6)
H2A	1.0963	0.5631	0.2671	0.059*
O3	0.4119 (4)	0.4426 (5)	0.2591 (2)	0.0951 (11)
O4	0.2982 (5)	0.6254 (5)	0.3782 (3)	0.1005 (13)
O5	0.7064 (6)	0.5609 (6)	0.4214 (4)	0.0507 (11)	0.50
H5	0.6847	0.5143	0.3468	0.061*	0.50
O6	0.5874 (7)	0.7540 (6)	0.5538 (4)	0.0569 (12)	0.50
H6	0.5146	0.7973	0.5366	0.068*	0.50
C1	0.9098 (4)	−0.0858 (4)	0.2372 (3)	0.0411 (7)
H1	0.9154	−0.2004	0.1977	0.049*
C2	0.8658 (5)	−0.0499 (5)	0.3569 (3)	0.0506 (8)
H2	0.8416	−0.1391	0.3979	0.061*
C3	0.8583 (5)	0.1207 (5)	0.4150 (3)	0.0538 (9)
H3	0.8274	0.1468	0.4955	0.065*
C4	0.8970 (4)	0.2526 (5)	0.3533 (3)	0.0459 (8)
H4	0.8936	0.3685	0.3915	0.055*
C5	0.9407 (4)	0.2086 (4)	0.2340 (2)	0.0339 (6)
C6	0.9820 (4)	0.3391 (4)	0.1516 (3)	0.0361 (6)
C7	0.8205 (4)	0.2618 (4)	0.0498 (3)	0.0365 (6)
C8	0.6957 (4)	0.3441 (4)	0.0418 (3)	0.0472 (8)
H8	0.7037	0.4522	0.1017	0.057*
C9	0.5585 (4)	0.2637 (5)	−0.0563 (3)	0.0540 (9)
H9	0.4729	0.3174	−0.0638	0.065*
C10	0.5493 (4)	0.1036 (5)	−0.1432 (3)	0.0483 (8)
H10	0.4593	0.0492	−0.2111	0.058*
C11	0.6747 (4)	0.0247 (4)	−0.1282 (3)	0.0420 (7)
H11	0.6665	−0.0854	−0.1858	0.050*
C12	0.4060 (4)	0.5461 (4)	0.3591 (3)	0.0436 (7)
C13	0.5422 (4)	0.5732 (4)	0.4673 (3)	0.0406 (7)
H13A	0.5713	0.6994	0.5271	0.049*	0.50
H13B	0.6568	0.5597	0.4349	0.049*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0397 (3)	0.0388 (3)	0.0277 (3)	0.0214 (2)	0.0000 (2)	0.0060 (2)
N1	0.0388 (13)	0.0359 (13)	0.0302 (12)	0.0188 (11)	0.0011 (10)	0.0092 (10)
N2	0.0385 (13)	0.0404 (13)	0.0289 (12)	0.0186 (11)	−0.0017 (10)	0.0063 (10)
O1	0.0425 (11)	0.0413 (11)	0.0322 (10)	0.0143 (9)	−0.0019 (9)	0.0090 (9)
O2	0.0607 (14)	0.0365 (12)	0.0458 (13)	0.0235 (10)	−0.0110 (11)	0.0002 (9)
O3	0.0785 (19)	0.152 (3)	0.0442 (15)	0.076 (2)	−0.0195 (14)	−0.0292 (17)
O4	0.130 (3)	0.121 (3)	0.0594 (18)	0.100 (2)	−0.0409 (17)	−0.0290 (17)
O5	0.041 (2)	0.062 (3)	0.051 (3)	0.019 (2)	0.001 (2)	0.019 (2)
O6	0.068 (3)	0.043 (3)	0.047 (3)	0.011 (2)	−0.012 (2)	0.006 (2)
C1	0.0428 (17)	0.0410 (17)	0.0433 (17)	0.0191 (14)	0.0003 (14)	0.0136 (14)
C2	0.053 (2)	0.062 (2)	0.0462 (19)	0.0234 (17)	0.0046 (15)	0.0292 (17)
C3	0.062 (2)	0.078 (2)	0.0307 (16)	0.0362 (19)	0.0097 (15)	0.0165 (17)
C4	0.0552 (19)	0.0545 (19)	0.0335 (16)	0.0310 (16)	0.0035 (14)	0.0077 (14)
C5	0.0353 (15)	0.0404 (16)	0.0290 (14)	0.0200 (13)	−0.0005 (12)	0.0070 (12)
C6	0.0447 (16)	0.0324 (15)	0.0325 (15)	0.0193 (13)	0.0014 (13)	0.0053 (12)
C7	0.0409 (16)	0.0378 (16)	0.0357 (16)	0.0178 (13)	0.0031 (13)	0.0143 (13)
C8	0.0534 (19)	0.0406 (17)	0.054 (2)	0.0253 (15)	0.0002 (16)	0.0138 (15)
C9	0.0451 (19)	0.058 (2)	0.069 (2)	0.0278 (17)	−0.0049 (17)	0.0218 (18)
C10	0.0428 (17)	0.057 (2)	0.0441 (18)	0.0197 (16)	−0.0083 (14)	0.0121 (16)
C11	0.0409 (17)	0.0451 (17)	0.0363 (16)	0.0159 (14)	−0.0037 (13)	0.0062 (13)
C12	0.0466 (18)	0.0448 (18)	0.0353 (17)	0.0162 (15)	0.0008 (14)	0.0062 (14)
C13	0.0396 (16)	0.0404 (17)	0.0375 (16)	0.0135 (13)	−0.0019 (13)	0.0066 (13)

Geometric parameters (Å, º)

Cu1—N1^i	2.003 (2)	C1—C2	1.377 (4)
Cu1—N1	2.003 (2)	C1—H1	0.9300
Cu1—N2^i	2.019 (2)	C2—C3	1.380 (5)
Cu1—N2	2.019 (2)	C2—H2	0.9300
Cu1—O1^i	2.3920 (19)	C3—C4	1.382 (5)
Cu1—O1	2.3920 (19)	C3—H3	0.9300
N1—C1	1.344 (4)	C4—C5	1.375 (4)
N1—C5	1.348 (3)	C4—H4	0.9300
N2—C11	1.339 (4)	C5—C6	1.549 (4)
N2—C7	1.345 (4)	C6—C7	1.526 (4)
O1—C6	1.417 (3)	C7—C8	1.373 (4)
O1—H1A	0.8554	C8—C9	1.376 (5)
O2—C6	1.382 (3)	C8—H8	0.9300
O2—H2A	0.8209	C9—C10	1.374 (5)
O3—C12	1.222 (4)	C9—H9	0.9300
O4—C12	1.213 (4)	C10—C11	1.374 (4)
O5—C13	1.409 (5)	C10—H10	0.9300
O5—H5	0.8134	C11—H11	0.9300
O5—H13B	0.4145	C12—C13	1.530 (4)
O6—C13	1.440 (5)	C13—C13^ii	1.527 (6)
O6—H6	0.8117	C13—H13A	1.0044
O6—H13A	0.4359	C13—H13B	0.9970
N1^i—Cu1—N1	180.0	N1—C5—C4	121.9 (3)
N1^i—Cu1—N2^i	88.92 (9)	N1—C5—C6	113.5 (2)
N1—Cu1—N2^i	91.08 (9)	C4—C5—C6	124.6 (3)
N1^i—Cu1—N2	91.08 (9)	O2—C6—O1	113.9 (2)
N1—Cu1—N2	88.92 (9)	O2—C6—C7	109.4 (2)
N2^i—Cu1—N2	180.0	O1—C6—C7	105.5 (2)
N1^i—Cu1—O1^i	75.89 (8)	O2—C6—C5	111.9 (2)
N1—Cu1—O1^i	104.11 (8)	O1—C6—C5	108.2 (2)
N2^i—Cu1—O1^i	73.63 (8)	C7—C6—C5	107.6 (2)
N2—Cu1—O1^i	106.37 (8)	N2—C7—C8	122.0 (3)
N1^i—Cu1—O1	104.11 (8)	N2—C7—C6	113.9 (2)
N1—Cu1—O1	75.89 (8)	C8—C7—C6	124.1 (3)
N2^i—Cu1—O1	106.37 (8)	C7—C8—C9	118.8 (3)
N2—Cu1—O1	73.63 (8)	C7—C8—H8	120.6
O1^i—Cu1—O1	180.00 (10)	C9—C8—H8	120.6
C1—N1—C5	119.4 (2)	C10—C9—C8	119.4 (3)
C1—N1—Cu1	124.79 (19)	C10—C9—H9	120.3
C5—N1—Cu1	115.84 (18)	C8—C9—H9	120.3
C11—N2—C7	118.8 (2)	C9—C10—C11	119.1 (3)
C11—N2—Cu1	125.7 (2)	C9—C10—H10	120.5
C7—N2—Cu1	115.45 (18)	C11—C10—H10	120.5
C6—O1—Cu1	93.97 (15)	N2—C11—C10	121.8 (3)
C6—O1—H1A	105.5	N2—C11—H11	119.1
Cu1—O1—H1A	116.8	C10—C11—H11	119.1
C6—O2—H2A	109.5	O4—C12—O3	124.4 (3)
C13—O5—H5	108.0	O4—C12—C13	118.5 (3)
C13—O5—H13B	5.1	O3—C12—C13	117.1 (3)
H5—O5—H13B	107.4	O5—C13—O6	107.9 (3)
C13—O6—H6	108.0	O5—C13—C12	108.8 (3)
C13—O6—H13A	2.7	O6—C13—C12	110.1 (3)
H6—O6—H13A	105.4	O5—C13—C13^ii	110.6 (3)
N1—C1—C2	121.5 (3)	O6—C13—C13^ii	109.6 (3)
N1—C1—H1	119.3	C12—C13—C13^ii	109.9 (3)
C2—C1—H1	119.3	O5—C13—H13A	108.8
C1—C2—C3	119.0 (3)	O6—C13—H13A	1.2
C1—C2—H2	120.5	C12—C13—H13A	109.0
C3—C2—H2	120.5	C13^ii—C13—H13A	109.7
C2—C3—C4	119.8 (3)	O5—C13—H13B	2.1
C2—C3—H3	120.1	O6—C13—H13B	109.5
C4—C3—H3	120.1	C12—C13—H13B	109.1
C5—C4—C3	118.5 (3)	C13^ii—C13—H13B	108.6
C5—C4—H4	120.7	H13A—C13—H13B	110.5
C3—C4—H4	120.7

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O3^iii	0.85	1.73	2.582 (3)	178
O2—H2A···O4^iii	0.82	1.84	2.648 (3)	170
O5—H5···O3	0.82	2.15	2.641 (5)	119
O6—H6···O4	0.82	2.22	2.693 (5)	118
C2—H2···O5^iv	0.93	2.38	3.249 (6)	156
C3—H3···O4^ii	0.93	2.50	3.217 (4)	134
C4—H4···O5	0.93	2.45	3.258 (5)	146

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