The first coordination compound of deprotonated 2-bromo­nicotinic acid: crystal structure of a dinuclear paddle-wheel copper(II) complex

The copper(II) ion has a distorted square-pyramidal coordination environment, achieved by four carboxyl­ate O atoms in the basal plane and the water mol­ecule in the apical position. The pair of symmetry-related copper(II) ions are connected into a centrosymmetric paddle-wheel dinuclear cluster via four O,O′-bridging 2-bromo­nicotinate ligands. In the extended structure, the cluster mol­ecules are assembled into an infinite two-dimensional hydrogen-bonded network lying parallel to the (001) plane via strong O—H...O and O—H...N hydrogen bonds, leading to the formation of various hydrogen-bond ring motifs: dimeric (8) and (16) loops and a tetra­meric (16) loop.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.009 Å
• R factor = 0.050
• wR factor = 0.134
• Data-to-parameter ratio = 12.8

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT910_ALERT_3_B Missing # of FCF Reflection(s) Below Theta(Min).         14 Note

Alert level C
PLAT220_ALERT_2_C NonSolvent Resd 1  C   Ueq(max) / Ueq(min) Range        3.1 Ratio
PLAT242_ALERT_2_C Low    MainMol Ueq as Compared to Neighbors of         C7 Check
PLAT341_ALERT_3_C Low Bond Precision on  C-C Bonds ...............     0.0091 Ang.
PLAT906_ALERT_3_C Large K Value in the Analysis of Variance ......      2.742 Check
PLAT911_ALERT_3_C Missing FCF Refl Between Thmin & STh/L=    0.595         13 Report
PLAT972_ALERT_2_C Check Calcd Resid. Dens.  0.83A   From Br2            -1.90 eA-3

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          3 Note
PLAT083_ALERT_2_G SHELXL Second Parameter in WGHT  Unusually Large      10.50 Why ?
PLAT172_ALERT_4_G The CIF-Embedded .res File Contains DFIX Records          2 Report
PLAT173_ALERT_4_G The CIF-Embedded .res File Contains DANG Records          1 Report
PLAT794_ALERT_5_G Tentative Bond Valency for Cu1       (II)      .       2.14 Info
PLAT860_ALERT_3_G Number of Least-Squares Restraints .............          3 Note
PLAT909_ALERT_3_G Percentage of I>2sig(I) Data at Theta(Max) Still        81% Note
PLAT933_ALERT_2_G Number of OMIT Records in Embedded .res File ...         13 Note
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density.          4 Info

   0 ALERT level A = Most likely a serious problem - resolve or explain
   1 ALERT level B = A potentially serious problem, consider carefully
   6 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   9 ALERT level G = General information/check it is not something unexpected

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


checkCIF publication errors

Alert level A
PUBL023_ALERT_1_A There is a mismatched ^ on line 32850
              {\rm MAPD} = {100\over N}\sum_{i=1}^{N}\bigg|{{q(i) - Q(i)}\over{q(i)}}\bigg|
              If you require a ^ then it should be escaped
              with a \, i.e. \^
              Otherwise there must be a matching closing ~, e.g. ^12^C

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

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Computing details

Data collection: CrysAlis PRO (Rigaku, 2018); cell refinement: CrysAlis PRO (Rigaku, 2018); data reduction: CrysAlis PRO (Rigaku, 2018); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018/3 (Sheldrick, 2015b); molecular graphics: Mercury (Macrae et al., 2008) and CrystalExplorer17.5 (Wolff et al., 2012); software used to prepare material for publication: SHELXL2018/3 (Sheldrick, 2015b).

Tetrakis(µ-2-bromonicotinato-κ²O:O')bis[aquacopper(II)](Cu—Cu)

Crystal data

[Cu2(C6H3BrNO2)4(H2O)2]	F(000) = 932
Mr = 967.13	Dx = 2.131 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 7.5596 (2) Å	Cell parameters from 7938 reflections
b = 9.7402 (3) Å	θ = 4.6–32.5°
c = 20.5332 (7) Å	µ = 6.77 mm^−1
β = 94.345 (3)°	T = 296 K
V = 1507.56 (8) Å^3	Prism, green–blue
Z = 2	0.59 × 0.42 × 0.33 mm

Data collection

Oxford Diffraction Xcalibur2 diffractometer with Sapphire 3 CCD detector	2392 reflections with I > 2σ(I)
ω–scan	Rint = 0.028
Absorption correction: multi-scan (CrysAlisPro; Rigaku, 2018)	θmax = 25.0°, θmin = 4.3°
Tmin = 0.288, Tmax = 1.000	h = −8→8
19205 measured reflections	k = −11→11
2622 independent reflections	l = −24→24

Refinement

Refinement on F^2	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.050	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.134	w = 1/[σ^2(Fo^2) + (0.0666P)^2 + 10.4972P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
2622 reflections	Δρmax = 1.34 e Å^−3
205 parameters	Δρmin = −2.06 e Å^−3
3 restraints

Special details

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

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

	x	y	z	Uiso*/Ueq
Cu1	0.65135 (8)	0.95254 (6)	0.48054 (3)	0.0136 (2)
Br1	0.35523 (10)	0.55987 (8)	0.58074 (4)	0.0462 (2)
Br2	0.97277 (15)	0.95629 (13)	0.67690 (5)	0.0838 (4)
N1	0.1831 (6)	0.4145 (5)	0.4818 (3)	0.0259 (10)
N2	0.8306 (9)	0.8063 (7)	0.7703 (3)	0.0518 (16)
O1	0.8705 (5)	0.8353 (4)	0.45349 (18)	0.0201 (8)
H11	0.969 (4)	0.857 (5)	0.469 (3)	0.024*
H12	0.852 (7)	0.758 (3)	0.466 (3)	0.024*
O2	0.4953 (5)	0.7928 (4)	0.4598 (2)	0.0251 (8)
O3	0.2397 (5)	0.8692 (4)	0.49343 (19)	0.0232 (8)
O4	0.6771 (5)	0.8938 (4)	0.57194 (17)	0.0265 (9)
O5	0.4213 (5)	0.9715 (4)	0.60518 (18)	0.0278 (9)
C1	0.2511 (7)	0.5362 (5)	0.4956 (3)	0.0214 (11)
C2	0.2524 (6)	0.6442 (5)	0.4517 (3)	0.0192 (11)
C3	0.1765 (8)	0.6213 (6)	0.3893 (3)	0.0318 (13)
H3	0.172615	0.691086	0.358327	0.038*
C4	0.1065 (9)	0.4933 (7)	0.3734 (3)	0.0361 (14)
H4	0.056199	0.474885	0.331615	0.043*
C5	0.1132 (8)	0.3943 (6)	0.4210 (3)	0.0314 (14)
H5	0.066424	0.308183	0.410259	0.038*
C6	0.3360 (7)	0.7797 (5)	0.4701 (2)	0.0186 (11)
C7	0.7871 (9)	0.8618 (7)	0.7123 (3)	0.0367 (15)
C8	0.6168 (8)	0.8574 (6)	0.6809 (3)	0.0258 (12)
C9	0.4876 (9)	0.7953 (8)	0.7142 (3)	0.0402 (16)
H9	0.370816	0.793989	0.696302	0.048*
C10	0.5309 (12)	0.7351 (9)	0.7740 (4)	0.054 (2)
H10	0.445567	0.689641	0.796168	0.065*
C11	0.7019 (13)	0.7440 (9)	0.7997 (3)	0.058 (2)
H11A	0.730394	0.704053	0.840298	0.069*
C12	0.5703 (7)	0.9133 (5)	0.6139 (2)	0.0211 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0134 (3)	0.0128 (3)	0.0144 (3)	0.0004 (2)	0.0001 (2)	0.0006 (2)
Br1	0.0477 (4)	0.0450 (4)	0.0450 (4)	−0.0018 (3)	−0.0018 (3)	0.0041 (3)
Br2	0.0700 (7)	0.1137 (9)	0.0637 (6)	−0.0456 (6)	−0.0206 (5)	0.0186 (6)
N1	0.019 (2)	0.014 (2)	0.045 (3)	0.0007 (18)	0.003 (2)	0.000 (2)
N2	0.066 (4)	0.057 (4)	0.029 (3)	0.007 (3)	−0.021 (3)	0.008 (3)
O1	0.0135 (17)	0.0172 (18)	0.030 (2)	0.0008 (14)	0.0027 (15)	−0.0025 (16)
O2	0.0172 (19)	0.0185 (19)	0.040 (2)	−0.0033 (14)	0.0033 (16)	−0.0058 (16)
O3	0.0155 (18)	0.0173 (18)	0.037 (2)	−0.0026 (14)	0.0034 (16)	−0.0043 (16)
O4	0.031 (2)	0.033 (2)	0.0157 (18)	0.0089 (17)	−0.0009 (16)	0.0044 (16)
O5	0.032 (2)	0.033 (2)	0.0184 (19)	0.0068 (18)	−0.0004 (16)	0.0049 (16)
C1	0.014 (2)	0.017 (3)	0.033 (3)	0.001 (2)	0.003 (2)	−0.001 (2)
C2	0.015 (2)	0.014 (2)	0.029 (3)	−0.0006 (19)	0.001 (2)	−0.001 (2)
C3	0.037 (3)	0.023 (3)	0.034 (3)	−0.005 (2)	−0.007 (3)	0.004 (2)
C4	0.036 (3)	0.032 (3)	0.038 (3)	−0.005 (3)	−0.011 (3)	−0.009 (3)
C5	0.024 (3)	0.017 (3)	0.051 (4)	−0.002 (2)	−0.005 (3)	−0.008 (3)
C6	0.018 (3)	0.016 (3)	0.021 (3)	−0.003 (2)	−0.003 (2)	0.003 (2)
C7	0.048 (4)	0.038 (3)	0.023 (3)	−0.004 (3)	−0.008 (3)	0.001 (3)
C8	0.037 (3)	0.025 (3)	0.015 (3)	0.005 (2)	−0.003 (2)	0.005 (2)
C9	0.045 (4)	0.048 (4)	0.027 (3)	0.003 (3)	0.005 (3)	0.012 (3)
C10	0.071 (5)	0.059 (5)	0.034 (4)	0.010 (4)	0.015 (4)	0.022 (3)
C11	0.089 (6)	0.060 (5)	0.024 (3)	0.007 (5)	0.002 (4)	0.023 (3)
C12	0.031 (3)	0.015 (2)	0.017 (3)	−0.001 (2)	−0.003 (2)	0.000 (2)

Geometric parameters (Å, º)

Cu1—O5^i	1.950 (4)	O5—C12	1.261 (7)
Cu1—O4	1.958 (4)	C1—C2	1.386 (8)
Cu1—O3^i	1.978 (4)	C2—C3	1.381 (8)
Cu1—O2	1.979 (4)	C2—C6	1.499 (7)
Cu1—O1	2.120 (4)	C3—C4	1.384 (9)
Cu1—Cu1^i	2.6470 (11)	C3—H3	0.9300
Br1—C1	1.875 (6)	C4—C5	1.371 (9)
Br2—C7	1.870 (7)	C4—H4	0.9300
N1—C1	1.314 (7)	C5—H5	0.9300
N1—C5	1.334 (8)	C7—C8	1.396 (9)
N2—C7	1.326 (8)	C8—C9	1.374 (9)
N2—C11	1.331 (11)	C8—C12	1.496 (7)
O1—H11	0.815 (10)	C9—C10	1.378 (9)
O1—H12	0.815 (10)	C9—H9	0.9300
O2—C6	1.245 (6)	C10—C11	1.362 (12)
O3—C6	1.254 (6)	C10—H10	0.9300
O4—C12	1.239 (7)	C11—H11A	0.9300
O5^i—Cu1—O4	167.76 (17)	C2—C3—C4	119.2 (6)
O5^i—Cu1—O3^i	89.64 (17)	C2—C3—H3	120.4
O4—Cu1—O3^i	89.35 (17)	C4—C3—H3	120.4
O5^i—Cu1—O2	88.95 (17)	C5—C4—C3	118.3 (6)
O4—Cu1—O2	89.47 (17)	C5—C4—H4	120.9
O3^i—Cu1—O2	167.80 (15)	C3—C4—H4	120.9
O5^i—Cu1—O1	98.06 (16)	N1—C5—C4	123.6 (5)
O4—Cu1—O1	94.05 (15)	N1—C5—H5	118.2
O3^i—Cu1—O1	103.05 (15)	C4—C5—H5	118.2
O2—Cu1—O1	89.15 (15)	O2—C6—O3	126.2 (5)
O5^i—Cu1—Cu1^i	87.08 (12)	O2—C6—C2	116.3 (5)
O4—Cu1—Cu1^i	80.69 (12)	O3—C6—C2	117.5 (4)
O3^i—Cu1—Cu1^i	87.92 (11)	N2—C7—C8	124.0 (6)
O2—Cu1—Cu1^i	79.91 (11)	N2—C7—Br2	114.0 (5)
O1—Cu1—Cu1^i	167.85 (11)	C8—C7—Br2	121.9 (5)
C1—N1—C5	117.1 (5)	C9—C8—C7	116.7 (5)
C7—N2—C11	117.0 (7)	C9—C8—C12	119.4 (5)
Cu1—O1—H11	118 (4)	C7—C8—C12	123.9 (5)
Cu1—O1—H12	105 (4)	C8—C9—C10	120.1 (7)
H11—O1—H12	107 (4)	C8—C9—H9	120.0
C6—O2—Cu1	127.8 (3)	C10—C9—H9	120.0
C6—O3—Cu1^i	118.1 (3)	C11—C10—C9	118.3 (7)
C12—O4—Cu1	126.8 (3)	C11—C10—H10	120.9
C12—O5—Cu1^i	119.1 (3)	C9—C10—H10	120.9
N1—C1—C2	124.5 (5)	N2—C11—C10	123.9 (6)
N1—C1—Br1	116.2 (4)	N2—C11—H11A	118.1
C2—C1—Br1	119.3 (4)	C10—C11—H11A	118.1
C3—C2—C1	117.3 (5)	O4—C12—O5	126.3 (5)
C3—C2—C6	120.9 (5)	O4—C12—C8	117.6 (5)
C1—C2—C6	121.8 (5)	O5—C12—C8	116.0 (5)
C5—N1—C1—C2	1.0 (8)	C11—N2—C7—C8	−0.5 (11)
C5—N1—C1—Br1	−178.0 (4)	C11—N2—C7—Br2	176.5 (6)
N1—C1—C2—C3	0.0 (8)	N2—C7—C8—C9	2.4 (10)
Br1—C1—C2—C3	179.0 (4)	Br2—C7—C8—C9	−174.4 (5)
N1—C1—C2—C6	−178.5 (5)	N2—C7—C8—C12	−176.5 (6)
Br1—C1—C2—C6	0.5 (7)	Br2—C7—C8—C12	6.7 (9)
C1—C2—C3—C4	−1.0 (9)	C7—C8—C9—C10	−3.3 (10)
C6—C2—C3—C4	177.6 (6)	C12—C8—C9—C10	175.6 (6)
C2—C3—C4—C5	0.9 (10)	C8—C9—C10—C11	2.6 (12)
C1—N1—C5—C4	−1.1 (9)	C7—N2—C11—C10	−0.4 (13)
C3—C4—C5—N1	0.2 (10)	C9—C10—C11—N2	−0.7 (14)
Cu1—O2—C6—O3	3.4 (8)	Cu1—O4—C12—O5	2.3 (8)
Cu1—O2—C6—C2	−177.5 (3)	Cu1—O4—C12—C8	179.3 (4)
Cu1^i—O3—C6—O2	−2.0 (7)	Cu1^i—O5—C12—O4	−2.9 (8)
Cu1^i—O3—C6—C2	178.9 (3)	Cu1^i—O5—C12—C8	−179.9 (4)
C3—C2—C6—O2	−87.8 (6)	C9—C8—C12—O4	−138.3 (6)
C1—C2—C6—O2	90.7 (6)	C7—C8—C12—O4	40.6 (8)
C3—C2—C6—O3	91.3 (6)	C9—C8—C12—O5	39.0 (8)
C1—C2—C6—O3	−90.2 (6)	C7—C8—C12—O5	−142.2 (6)

Symmetry code: (i) −x+1, −y+2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H11···O3^ii	0.82 (1)	2.07 (2)	2.868 (5)	165 (6)
O1—H12···N1^iii	0.82 (1)	2.02 (2)	2.816 (6)	166 (6)
C11—H11A···O1^iv	0.93	2.51	3.403 (8)	161

Symmetry codes: (ii) x+1, y, z; (iii) −x+1, −y+1, −z+1; (iv) x, −y+3/2, z+1/2.