Bis­(di­methylamine-κN)bis[4-(1,2,4-triazol-1-yl)benzoato-κO]copper(II)

A three-dimensional supermolecule based on 4-(1,2,4-triazol-1-yl)benzoic acid was prepared under solvothermal conditions. In the crystal, inter­molecular N—H⋯N hydrogen bonds between the amine function and the central N atom of the triazole ring lead to the formation of ribbons parallel to [1 1].

Abstract

In the title compound, [Cu(C₉H₆N₃O₂)₂(C₂H₇N)₂], the Cu²⁺ cation is situated on an inversion center and is coordinated by the N atoms of two di­methyl­amine ligands and the carboxyl­ate O atoms of two 4-(1,2,4-triazol-1-yl)benzoate anions, leading to a slightly distorted square-planar N₂O₂ coordination environment. In the crystal, inter­molecular N—H⋯N hydrogen bonds between the amine function and the central N atom of the triazole ring lead to the formation of ribbons parallel to [1 1]. Weak inter­molecular C—H⋯O hydrogen-bonding inter­actions are also observed that consolidate the crystal packing.

Structure description

The rational design of coordination polymers is based on the combination of metal ions and versatile organic ligands, resulting in various supra­molecular assemblies. The resulting crystal structures determine the potential applications of the coordination polymers. Different polymers based on 4-(1,2,4-triazol-1-yl)benzoic acid complexes have been reported (Du et al., 2014 ▸). They not only feature structural varieties, but also can be applied in gas storage (Wang et al., 2012 ▸). In this context we have investigated crystals formed from a copper(II) solution and 4-(1,2,4-triazol-1-yl)benzoic acid under solvothermal conditions.

As shown in Fig. 1 ▸, the asymmetric unit of the title compound comprises one Cu^II atom, one 4-(1,2,4-triazol-1-yl)benzoate ligand, and one di­methyl­amine mol­ecule generated in situ from the decomposition of the solvent dimethyl formamide. The complete mol­ecule is generated by inversion symmetry. The Cu^II atom has a distorted square-planar coordination environment, being coordinated by two symmetry-related benzoato O atoms [Cu—O1 = 1.9611 (14) Å] and two symmetry-related N atoms [Cu—N4 = 2.0096 (19) Å of the amine ligands. The second carboxyl­ate O atom of the anion seems to be too far away [Cu—O2 = 2.80136 (19) Å] to contribute to a significant bonding. Nevertheless, the non-bonding O2 atom is involved as an acceptor in weak C—H⋯O hydrogen-bonding inter­actions (Table 1 ▸, Fig. 2 ▸). Stronger N—H⋯N hydrogen bonds between the amine NH group and the central N atom of the triazole ring are also observed.

Figure 1.

The mol­ecular structure of the title compound, with atom labelling and displacement ellipsoids drawn at the 30% probability level. H atoms have been omitted for clarity. [Symmetry code: (A) −x + 2, −y, −z + 1.]

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4⋯N3i	0.91	2.17	3.034 (3)	160
C9—H9A⋯O2ii	0.93	2.50	3.428 (3)	173

Symmetry codes: (i) ; (ii) .

Figure 2.

The crystal packing of the complex mol­ecules. Hydrogen-bonding inter­actions are shown as dashed lines.

Synthesis and crystallization

A mixture of Cu(NO₃)₂·3H₂O (0.0725 mg, 0.3 mmol), 4-(1,2,4-triazol-1-yl)benzoic acid (0.057 g, 0.3 mmol), di­methyl­formamide (5 ml), ethanol (5 ml) and water (5 ml) was placed in a Teflon reactor with a 23 ml capacity, which was heated at 433 K for 3 days and then cooled to room temperature at a rate of 10 K h⁻¹. Blue block-shaped crystals of the title compound were obtained in 52% yield after being washed with di­methyl­formamide and dried in air.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸.

Table 2. Experimental details.

Crystal data
Chemical formula	[Cu(C9H6N3O2)2(C2H7N)2]
M r	530.06
Crystal system, space group	Triclinic, P
Temperature (K)	293
a, b, c (Å)	6.3657 (5), 8.1428 (7), 12.1896 (11)
α, β, γ (°)	72.595 (2), 89.376 (2), 87.805 (2)
V (Å3)	602.47 (9)
Z	1
Radiation type	Mo Kα
μ (mm−1)	0.95
Crystal size (mm)	0.36 × 0.32 × 0.27
Data collection
Diffractometer	Bruker SMART CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2002 ▸)
T min, T max	0.727, 0.785
No. of measured, independent and observed [I > 2σ(I)] reflections	3971, 2727, 2345
R int	0.017
(sin θ/λ)max (Å−1)	0.650
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.038, 0.093, 1.03
No. of reflections	2727
No. of parameters	160
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.28, −0.20

Computer programs: SMART and SAINT (Bruker, 2002 ▸), SHELXS97 (Sheldrick, 2008 ▸), SHELXL (Sheldrick, 2015 ▸), Mercury (Macrae et al., 2020 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

CCDC reference: 2141669

Additional supporting information: crystallographic information; 3D view; checkCIF report

full crystallographic data

Crystal data

[Cu(C9H6N3O2)2(C2H7N)2]	Z = 1
Mr = 530.06	F(000) = 275
Triclinic, P1	Dx = 1.461 Mg m−3
a = 6.3657 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.1428 (7) Å	Cell parameters from 1477 reflections
c = 12.1896 (11) Å	θ = 2.6–26.4°
α = 72.595 (2)°	µ = 0.95 mm−1
β = 89.376 (2)°	T = 293 K
γ = 87.805 (2)°	Block, blue
V = 602.47 (9) Å3	0.36 × 0.32 × 0.27 mm

Data collection

Bruker SMART CCD diffractometer	2727 independent reflections
Radiation source: fine-focus sealed tube	2345 reflections with I > 2σ(I)
Detector resolution: 10.0 pixels mm-1	Rint = 0.017
ω scan	θmax = 27.5°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2002)	h = −8→8
Tmin = 0.727, Tmax = 0.785	k = −10→10
3971 measured reflections	l = −10→15

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.038	H-atom parameters constrained
wR(F2) = 0.093	w = 1/[σ2(Fo2) + (0.0482P)2 + 0.1332P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max < 0.001
2727 reflections	Δρmax = 0.28 e Å−3
160 parameters	Δρmin = −0.20 e Å−3

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	1.000000	0.000000	0.500000	0.03668 (13)
O1	0.8278 (3)	0.19597 (19)	0.40688 (13)	0.0456 (4)
N4	0.8929 (3)	−0.1440 (2)	0.40592 (16)	0.0478 (5)
H4	0.834029	−0.069234	0.342060	0.072*
O2	1.0899 (3)	0.2218 (2)	0.28158 (16)	0.0564 (5)
N3	0.3345 (3)	0.9752 (2)	−0.18059 (16)	0.0470 (5)
C8	0.1967 (4)	0.9638 (3)	−0.0944 (2)	0.0475 (5)
H8A	0.069359	1.026329	−0.105518	0.057*
N1	0.4455 (3)	0.7973 (2)	−0.01740 (15)	0.0357 (4)
C1	0.9149 (3)	0.2671 (3)	0.31047 (18)	0.0397 (5)
C2	0.7914 (3)	0.4135 (2)	0.22845 (17)	0.0347 (4)
C3	0.8841 (3)	0.5111 (3)	0.1285 (2)	0.0443 (5)
H3A	1.024977	0.489576	0.114867	0.053*
C4	0.7728 (3)	0.6395 (3)	0.0487 (2)	0.0462 (5)
H4A	0.838250	0.704495	−0.017864	0.055*
C5	0.5630 (3)	0.6712 (2)	0.06815 (17)	0.0332 (4)
C6	0.4692 (3)	0.5793 (3)	0.16901 (19)	0.0429 (5)
H6A	0.329651	0.603747	0.183663	0.052*
C7	0.5831 (3)	0.4506 (3)	0.24845 (18)	0.0438 (5)
H7A	0.518902	0.388216	0.316208	0.053*
C9	0.4888 (4)	0.8692 (3)	−0.12927 (18)	0.0437 (5)
H9A	0.611277	0.846901	−0.165463	0.052*
N2	0.2529 (3)	0.8588 (2)	0.00657 (16)	0.0467 (5)
C11	1.0630 (5)	−0.2323 (4)	0.3597 (3)	0.0766 (9)
H11A	1.164757	−0.150450	0.321505	0.115*
H11B	1.129585	−0.320275	0.421504	0.115*
H11C	1.005285	−0.283743	0.305845	0.115*
C10	0.7338 (6)	−0.2657 (4)	0.4651 (3)	0.0853 (10)
H10A	0.624985	−0.205376	0.494376	0.128*
H10B	0.674023	−0.317305	0.411925	0.128*
H10C	0.798323	−0.353837	0.527585	0.128*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cu1	0.0456 (2)	0.0340 (2)	0.02439 (18)	0.00871 (14)	−0.00500 (14)	−0.00062 (13)
O1	0.0569 (9)	0.0417 (8)	0.0312 (7)	0.0137 (7)	−0.0080 (7)	−0.0019 (6)
N4	0.0643 (12)	0.0411 (10)	0.0328 (9)	0.0055 (9)	−0.0129 (9)	−0.0034 (8)
O2	0.0430 (9)	0.0580 (10)	0.0580 (11)	0.0168 (8)	−0.0055 (8)	−0.0038 (8)
N3	0.0571 (11)	0.0418 (10)	0.0366 (10)	0.0088 (8)	−0.0123 (9)	−0.0043 (8)
C8	0.0512 (13)	0.0448 (12)	0.0427 (12)	0.0162 (10)	−0.0140 (10)	−0.0089 (10)
N1	0.0387 (9)	0.0317 (8)	0.0330 (8)	0.0042 (7)	−0.0060 (7)	−0.0045 (7)
C1	0.0453 (12)	0.0350 (10)	0.0360 (11)	0.0061 (9)	−0.0121 (9)	−0.0069 (8)
C2	0.0388 (10)	0.0325 (9)	0.0305 (10)	0.0036 (8)	−0.0075 (8)	−0.0060 (8)
C3	0.0333 (10)	0.0467 (12)	0.0446 (12)	0.0055 (9)	−0.0017 (9)	−0.0018 (10)
C4	0.0398 (11)	0.0451 (12)	0.0412 (12)	0.0019 (9)	0.0036 (9)	0.0055 (9)
C5	0.0365 (10)	0.0288 (9)	0.0315 (10)	0.0025 (8)	−0.0064 (8)	−0.0051 (7)
C6	0.0350 (10)	0.0496 (12)	0.0366 (11)	0.0087 (9)	0.0009 (9)	−0.0027 (9)
C7	0.0449 (12)	0.0460 (12)	0.0311 (10)	0.0067 (9)	0.0029 (9)	0.0017 (9)
C9	0.0482 (12)	0.0427 (11)	0.0349 (11)	0.0050 (9)	−0.0043 (9)	−0.0040 (9)
N2	0.0425 (10)	0.0498 (11)	0.0407 (10)	0.0145 (8)	−0.0048 (8)	−0.0049 (8)
C11	0.100 (2)	0.0749 (19)	0.0628 (18)	0.0288 (17)	−0.0177 (17)	−0.0357 (16)
C10	0.103 (3)	0.082 (2)	0.065 (2)	−0.0332 (19)	−0.0135 (18)	−0.0088 (17)

Geometric parameters (Å, º)

Cu1—O1	1.9611 (14)	C2—C3	1.380 (3)
Cu1—O1i	1.9612 (14)	C2—C7	1.384 (3)
Cu1—N4	2.0096 (19)	C3—C4	1.375 (3)
Cu1—N4i	2.0096 (19)	C3—H3A	0.9300
O1—C1	1.276 (3)	C4—C5	1.382 (3)
N4—C10	1.470 (4)	C4—H4A	0.9300
N4—C11	1.475 (4)	C5—C6	1.377 (3)
N4—H4	0.9071	C6—C7	1.382 (3)
O2—C1	1.240 (3)	C6—H6A	0.9300
N3—C9	1.314 (3)	C7—H7A	0.9300
N3—C8	1.345 (3)	C9—H9A	0.9300
C8—N2	1.315 (3)	C11—H11A	0.9600
C8—H8A	0.9300	C11—H11B	0.9600
N1—C9	1.343 (3)	C11—H11C	0.9600
N1—N2	1.368 (2)	C10—H10A	0.9600
N1—C5	1.421 (2)	C10—H10B	0.9600
C1—C2	1.507 (3)	C10—H10C	0.9600
O1—Cu1—O1i	180.00 (8)	C3—C4—C5	119.5 (2)
O1—Cu1—N4	89.16 (7)	C3—C4—H4A	120.2
O1i—Cu1—N4	90.84 (7)	C5—C4—H4A	120.2
O1—Cu1—N4i	90.84 (7)	C6—C5—C4	119.96 (18)
O1i—Cu1—N4i	89.16 (7)	C6—C5—N1	120.69 (18)
N4—Cu1—N4i	180.00 (7)	C4—C5—N1	119.34 (18)
C1—O1—Cu1	111.32 (13)	C5—C6—C7	119.81 (19)
C10—N4—C11	111.0 (2)	C5—C6—H6A	120.1
C10—N4—Cu1	113.77 (18)	C7—C6—H6A	120.1
C11—N4—Cu1	112.97 (17)	C6—C7—C2	120.9 (2)
C10—N4—H4	108.7	C6—C7—H7A	119.6
C11—N4—H4	103.5	C2—C7—H7A	119.6
Cu1—N4—H4	106.2	N3—C9—N1	110.8 (2)
C9—N3—C8	102.46 (18)	N3—C9—H9A	124.6
N2—C8—N3	116.0 (2)	N1—C9—H9A	124.6
N2—C8—H8A	122.0	C8—N2—N1	101.72 (18)
N3—C8—H8A	122.0	N4—C11—H11A	109.5
C9—N1—N2	109.03 (17)	N4—C11—H11B	109.5
C9—N1—C5	129.63 (18)	H11A—C11—H11B	109.5
N2—N1—C5	121.27 (17)	N4—C11—H11C	109.5
O2—C1—O1	124.09 (19)	H11A—C11—H11C	109.5
O2—C1—C2	119.7 (2)	H11B—C11—H11C	109.5
O1—C1—C2	116.21 (18)	N4—C10—H10A	109.5
C3—C2—C7	118.30 (18)	N4—C10—H10B	109.5
C3—C2—C1	119.88 (19)	H10A—C10—H10B	109.5
C7—C2—C1	121.79 (19)	N4—C10—H10C	109.5
C4—C3—C2	121.5 (2)	H10A—C10—H10C	109.5
C4—C3—H3A	119.3	H10B—C10—H10C	109.5
C2—C3—H3A	119.3
C9—N3—C8—N2	−0.1 (3)	C9—N1—C5—C4	17.1 (3)
Cu1—O1—C1—O2	−2.6 (3)	N2—N1—C5—C4	−166.2 (2)
Cu1—O1—C1—C2	176.67 (13)	C4—C5—C6—C7	−2.7 (3)
O2—C1—C2—C3	−8.7 (3)	N1—C5—C6—C7	176.47 (19)
O1—C1—C2—C3	172.0 (2)	C5—C6—C7—C2	0.5 (4)
O2—C1—C2—C7	169.3 (2)	C3—C2—C7—C6	1.6 (3)
O1—C1—C2—C7	−10.0 (3)	C1—C2—C7—C6	−176.4 (2)
C7—C2—C3—C4	−1.6 (4)	C8—N3—C9—N1	0.0 (3)
C1—C2—C3—C4	176.4 (2)	N2—N1—C9—N3	0.0 (3)
C2—C3—C4—C5	−0.5 (4)	C5—N1—C9—N3	177.02 (19)
C3—C4—C5—C6	2.7 (3)	N3—C8—N2—N1	0.1 (3)
C3—C4—C5—N1	−176.5 (2)	C9—N1—N2—C8	0.0 (2)
C9—N1—C5—C6	−162.0 (2)	C5—N1—N2—C8	−177.35 (18)
N2—N1—C5—C6	14.7 (3)

Symmetry code: (i) −x+2, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N4—H4···N3ii	0.91	2.17	3.034 (3)	160
C9—H9A···O2iii	0.93	2.50	3.428 (3)	173

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

Funding Statement

Funding for this research was provided by: Scientific Research Foundation of the Education Department of Liaoning Province (grant No. LJC202004).