Cobalt(II) chloride complexes with 1,1′-dimethyl-4,4′-bi­pyrazole featuring first- and second-sphere coordination of the ligand

In catena-poly[[di­chlorido­cobalt(II)]-μ-(1,1′-dimethyl-4,4′-bi­pyrazole-κ²N²:N^2′)], [CoCl₂(C₈H₁₀N₄)]_n, (1), two independent bi­pyrazole ligands (Me₂bpz) are situated across centres of inversion and in tetra­aqua­bis­(1,1′-dimethyl-4,4′-bi­pyrazole-κN²)cobalt(II) dichloride–1,1′-dimethyl-4,4′-bi­pyrazole–water (1/2/2), [Co(C₈H₁₀N₄)₂(H₂O)₄]Cl₂·2C₈H₁₀N₄·2H₂O, (2), the Co²⁺ cation lies on an inversion centre and two noncoordinated Me₂bpz mol­ecules are also situated across centres of inversion. The compounds are the first complexes involving N,N′-disubstituted 4,4′-bi­pyrazole tectons. They reveal a relatively poor coordination ability of the ligand, resulting in a Co–pyrazole coordination ratio of only 1:2. Compound (1) adopts a zigzag chain structure with bitopic Me₂bpz links between tetra­hedral Co^II ions. Inter­chain inter­actions occur by means of very weak C—H...Cl hydrogen bonding. Complex (2) comprises discrete octa­hedral trans-[Co(Me₂bpz)₂(H₂O)₄]²⁺ cations formed by monodentate Me₂bpz ligands. Two equivalents of additional noncoordinated Me₂bpz tectons are important as `second-sphere ligands' connecting the cations by means of relatively strong O—H...N hydrogen bonding with generation of doubly inter­penetrated pcu (α-Po) frameworks. Noncoordinated chloride anions and solvent water mol­ecules afford hydrogen-bonded [(Cl⁻)₂(H₂O)₂] rhombs, which establish topological links between the above frameworks, producing a rare eight-coordinated uninodal net of {4²⁴.5.6³} (ilc) topology.

S1. Introduction

Multipurpose applications of 4,4'-bi­pyrazoles for supra­molecular synthesis concern their diverse chemical behaviour and a range of structural roles for sustaining structures of framework solids, in particular as covalent bipyrazolate bridges (Pettinari et al., 2012), self-complementary hydrogen-bond donors and acceptors (Boldog et al., 2001) and cationic bipyrazolium tectons, which act as multiple hydrogen-bond donors (Boldog et al., 2009; Domasevitch, 2012). For each of these cases, the NH site of the pyrazole ring is a key functional prerequisite. Considering functions of bi­pyrazoles as simple bitopic coordination links between metal ions (Boldog et al., 2002; Tâbâcaru et al., 2012), the NH sites are also important. They commonly provide a peculiar hydrogen bonding with anionic co-ligands (Naza­renko et al., 2013; Ponomarova et al., 2013), thus appreciably contributing to the overal structure. Therefore, the substitution at the N¹ atom of the pyrazole ring could be of primary significance for fine-tuning properties of the ligands in view of their ability for bridging metal ions and sustaining secondary inter­actions. The resulting N-substituted bi­pyrazoles combine such inputs as structural simplicity and chemical accessibility, being readily available either by alkyl­ation of pyrazole ring or by heterocylization of di­aldehyde precursor when reacted with substituted hydrazines (Timmermans et al., 1972). The steric effect of N-substituent could mitigate against coordination of many pyrazole rings, which may be important for control over formation of second-sphere hydrogen-bonded complexes rather than assembly of more common coordination polymers, similar to versatile 4,7-phenanthroline systems developed by Beauchamp & Loeb (2002). However, the coordination behaviour of N-substituted bi­pyrazoles and their utility as potentially suitable tectons for generation of supra­molecular architectures does not appear to have been considered. In this context, we have examined prototypical bitopic ligand 1,1'-di­methyl-4,4'-bi­pyrazole (Me₂bpz) and in the present contribution we report two coordination compounds of cobalt(II) chloride, namely catena-poly[[dichloridocobalt(II)]-µ- (1,1'-di­methyl-4,4'-bi­pyrazole-κ²N²:N^2')], (1), and tetra­aqua­bis­(1,1'-di­methyl-4,4'-bi­pyrazole-κN²)cobalt(II) dichloride–1,1'-di­methyl-4,4'-bi­pyrazole–water (1/2/2), (2).

S2. Experimental

S2.1. Synthesis and crystallization

The 1,1'-di­methyl-4,4'-bi­pyrazole ligand (Me₂bpz) was synthesized following the method of Timmermans et al. (1972). The title coordination compounds were prepared by slow evaporation of methanol solutions (4 ml) of the components. In this way, reaction of CoCl₂.6H₂O (26.2 mg, 0.110 mmol) and Me₂bpz (16.2 mg, 0.100 mmol) gives elongated blue prisms of [CoCl₂(Me₂bpz)], (1), in 80% yield (23 mg) and reaction of CoCl₂.6H₂O (11.9 mg, 0.050 mmol) and Me₂bpz (35.6 mg, 0.220 mmol) provides light-pink blocks of [Co(H₂O)₄(Me₂bpz)₂]Cl₂.2Me₂bpz.2H₂O, (2), in 90% yield (39 mg). With the initial molar ratios of the components varied between 1:1 and 1:4, the resulting crystalline materials were mixtures of both (1) and (2).

Elemental analysis calculated for (1): C 32.90, H 3.45, N 19.19%; found: C 32.73, H 3.49, N 19.08%. Elemental analysis calculated for (2): C 43.34, H 5.91, N 25.28%; found: C 43.47, H 5.82, N 25.40%.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. All C—H hydrogens were located from difference maps and then refined as riding, with the angles constrained, C—H distances constrained to 0.94 (pyrazole) or 0.97 Å (methyl) and U_iso(H) = 1.5U_eq(C) for methyl H atoms and 1.2U_eq(C) otherwise. For (2), all water H atoms were found in inter­mediate difference Fourier maps and were refined fully with isotropic displacement parameters [O—H = 0.77 (3)–0.91 (3) Å].

S3. Results and discussion

In the structure of complex (1), two independent 1,1'-di­methyl-4,4'-bi­pyrazole (Me₂bpz) ligands reside across centres of inversion. Distorted coordination tetra­hedra of Co ions comprise two chloride ligands and two N atoms of bi­pyrazole ligands (Table 2). Such geometry is also known for the dichloridocobalt(II) complex with 1,2-bis­(pyridin-4-yl)ethane (Wang, 2008). The resulting one-dimensional polymeric chains run along the b direction. They afford very weak C—H···Cl hydrogen bonds [C···Cl1ⁱⁱⁱ = 3.588 (2) Å and C2—H2···Cl1ⁱⁱⁱ = 162°; symmetry code: (iii) -x+1/2, y+1/2, -z+1/2].

The structure of (2) is ionic, it comprises complex [Co(H₂O)₄(Me₂bpz)₂]²⁺ dications, two independent noncoordinated Me₂bpz molecules (all three entitites are situated across centres of inversion), solvent water molecules and noncoordinated chloride anions (Table 3 and Fig. 3). The latter constitute centrosymmetric discrete dichlorido/di­aqua ensembles, with typical O—H···Cl hydrogen-bond distances (Table 4). The metal ions have a trans-o­cta­hedral [CoN₂O₄] environment comprising two monodentate Me₂bpz ligands, and the Co1—N2 bonds [2.2145 (13) Å] appear to be certainly longer than the Co1—O bonds involving the aqua ligands [2.0395 (11) and 2.1095 (12) Å]. Thus, even under a significant excess of the organic ligand in the reaction mixture, the product manifests relatively low actual coordination Co–pyrazole ratio of only 1:2, similar to complex (1). This is contrary to unsubstituted 4,4'-bi­pyrazole (H₂bpz), which typically forms two-dimensional square-grid polymers {[Co(H₂bpz)₂Cl₂].Guest}_n (Boldog et al., 2002). The relatively poor coordination ability of Me₂bpz is unlikely influenced by the steric effect of the methyl group only; elimination of stabilizing hydrogen-bond inter­actions between coordinated pyrazole and anionic co-ligands (which are typical for complexes of N-unsubstituted bi­pyrazoles) (Ponomarova et al., 2013) could be also important. At first glance, this precludes organization of extended frameworks based upon Me₂bpz.

The Me₂bpz tectons, either monodentate or noncoordinated, are crucial for sustaining the present complex structure rather as ligands of a second coordination sphere (Beauchamp & Loeb, 2002). Every pyrazole group is a hydrogen-bond acceptor and establishes a relatively short and directional O—H···N hydrogen bond with the coordinated H₂O donors (Table 4). In this way, topological linkage of the metal ions (the framework nodes) is based upon hydrogen-bonded Co—OH₂···Me₂bpz···H₂O—Co bridges or combined coordination and hydrogen-bonded Co—Me₂bpz···H₂O—Co bridges. Such behaviour has few precedents in the chemistry of 4,4'-bi­pyridine, rarely acting as a double hydrogen-bond acceptor towards metal–aqua cations (Carlucci et al., 1997) or as a monodentate ligand and acceptor of one M—OH₂···N hydrogen bond (Dong et al., 2000; Abu-Shandi et al., 2001). It is worth noting that the second-sphere coordination of heterocyclic nitro­gen bases, when combined with the metal–aqua cations, has received growing inter­est with respect to developing systems for molecular recognition (Maldonado et al., 2012).

Double bridges of the Co—Me₂bpz···H₂O—Co type lead to pair-wise association of the [Co(H₂O)₄(Me₂bpz)₂]²⁺ cations, giving rise to linear one-dimensional chains along the b direction, with a Co···Co separation of 11.1415 (10) Å (parameter b of the unit cell) (Fig. 4). Both noncoordinated Me₂bpz molecules are acceptors of two O—H···N hydrogen bonds and connect tetra­aqua­cobalt fragments in the ac plane [Co···Co = 14.1037 (10) and 14.4921 (10) Å]. The resulting cationic three-dimensional framework has composition {[Co(H₂O)₄(Me₂bpz)₂](Me₂bpz)₂}_n²ⁿ⁺. It possesses a primitive cubic net topology with a point symbol of {4¹².6³} (α-Po; three-letter notation `pcu') and two identical nets, related by a single translation vector, are inter­penetrated (class Ia inter­penetration, Z = 2) (Blatov et al., 2004).

This connectivity employs six out of eight available O—H donors at the tetra­aqua­cobalt node and the remaining two O—H donors generate additional inter­nodal links through strong O—H···OH₂ hydrogen bonding [O···O = 2.6939 (18) Å; Table 4] to the above [(Cl^-)₂(H₂O)₂] assemblies (Fig. 4). These bridges unite the above independent nets. When these links are also considered for the entire topology, the inter­penetration disappears and a single uninodal eight-connected net is found, with a point Schläfli symbol {4²⁴.5.6³} (Fig. 5). This net is identified by a `ilc' notation in the Reticular Chemistry Structure Resource database (Blatov & Shevchenko, 1999) and it has only one precedent in crystal structures. It is notable that this topology was initially rationalized in terms of inter­linking of two inter­penetrated pcu frameworks (Wang et al., 2005), and therefore the present case is very illustrative for the close relation of pcu and ilc nets.

Weaker inter­actions in the structure comprise extensive hydrogen bonding of polarized pyrazole C—H groups and sterically accessible chloride anions of [(Cl^-)₂(H₂O)₂]. In addition to two convenient O—H···Cl hydrogen bonds, the chloride accepts in total six directional C—H···Cl hydrogen bonds [C···Cl = 3.5153 (19)–3.738 (2) Å; Table 4]. This kind of weak hydrogen bonding is greatly favored by the bi­pyrazole structure, which provides multiple C—H donor sites for sustaining the `chelate-like' pattern (Fig. 6). tetra­aqua­bis­(1,1'-di­methyl-4,4'-bi­pyrazole-κN<sup>2</sup>)cobalt(II) dichloride–1,1'-di­methyl-4,4'-bi­pyrazole–water (1/2/2) In summary, our study introduces a new tecton for supra­molecular synthesis. In spite of the relative simplicity of coordination patterns adopted by Me<sub>2</sub>bpz, it could find special and peculiar applications as a `second-sphere ligand' for bridging of metal–aqua cations {[M(H₂O)]⁺}_n by hydrogen bonding. This complements and expands structural potential of unsubstituted bi­pyrazole tectons, the common type of bitopic N-donor coordination linkers.

Related literature

For related literature, see: Abu-Shandi, Janiak & Kersting (2001); Beauchamp & Loeb (2002); Blatov & Shevchenko (1999); Blatov et al. (2004); Boldog et al. (2001, 2002, 2009); Carlucci et al. (1997); Domasevitch (2012); Dong et al. (2000); Maldonado et al. (2012); Nazarenko et al. (2013); Pettinari et al. (2012); Ponomarova et al. (2013); Tâbâcaru et al. (2012); Timmermans et al. (1972); Wang (2008); Wang et al. (2005).

Computing details

For both compounds, data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-NT (Bruker, 1999); data reduction: SAINT-NT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures

	Fig. 1. The structure of (1), showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 40% probability level. N and Cl atoms are shaded grey and H atoms are shown as small spheres of arbitrary radii. [Symmetry codes: (i) -x+1, -y+1, -z; (ii) -x+1, -y, -z+1.]
	Fig. 2. A projection of the structure of (1) on the ab plane, showing the zigzag coordination chains of [CoCl2(Me2bpz)]n and a set of interchain interactions by weak C—H···Cl hydrogen bonding. [Symmetry code: (iii) -x+1/2, y+1/2, -z+1/2.]
	Fig. 3. The structure of (2), showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 40% probability level, N, O and Cl atoms are shaded grey and C-linked H atoms have been amitted for clarity. The convenient hydrogen bonding is indicated by dashed lines. [Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x, -y+2, -z; (iii) -x+2, -y+1, -z; (v) -x+2, -y, -z+1.]
	Fig. 4. Fragment of the structure of (2), showing mode of hydrogen bonding between [Co(H2O)4(Me2bpz)2]^2+ cations with generation of linear chains along the b direction. [Symmetry codes: (i) -x+1, -y+1, -z+1; (iv) x, y+1, -z; (v) -x+2, -y, -z+1.]
	Fig. 5. A projection of the structure of (2) on the ac plane, showing two interpenetrated hydrogen-bonded frameworks {[Co(Me2bpz)2(H2O)4](Me2bpz)2}n^2^n^+ (indicated with bold and open bonds and two additional topological links of the frameworks are orthogonal to the drawing plane) and how they are linked by hydrogen bonding to [Cl^-2(H2O)2] associates. [Symmetry codes: (ii) -x, -y+2, -z; (iii) -x+2, -y+1, -z; (v) -x+2, -y, -z+1.]
	Fig. 6. The hydrogen-bonded environment of the noncoordinated chloride anions in the structure of (2) (N and O atoms are shaded grey). Note the `chelate-like' function of Me2bpz molecules, as multiple C—H···Cl hydrogen-bond donors. [Symmetry codes: (iii) -x+2, -y+1, -z; (v) -x+2, -y, -z+1; (vi) -x+1, -y+1, -z; (vii) x+1, y-1, z.]

(1) catena-Poly[[dichloridocobalt(II)]-µ-(1,1'-dimethyl-4,4'-bipyrazole-κ²N²:N^2')]

Crystal data

[CoCl2(C8H10N4)]	F(000) = 588
Mr = 292.03	Dx = 1.657 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 8.8762 (8) Å	Cell parameters from 7256 reflections
b = 14.2372 (14) Å	θ = 2.6–27.9°
c = 9.5878 (9) Å	µ = 1.89 mm^−1
β = 104.964 (2)°	T = 223 K
V = 1170.54 (19) Å^3	Prism, blue
Z = 4	0.14 × 0.12 × 0.09 mm

Data collection

Siemens SMART CCD area-detector diffractometer	2763 independent reflections
Radiation source: fine-focus sealed tube	2061 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
ω scans	θmax = 27.9°, θmin = 2.6°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −11→7
Tmin = 0.785, Tmax = 0.857	k = −18→18
7256 measured reflections	l = −12→12

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)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.084	H-atom parameters constrained
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0511P)^2] where P = (Fo^2 + 2Fc^2)/3
2763 reflections	(Δ/σ)max = 0.001
138 parameters	Δρmax = 0.48 e Å^−3
0 restraints	Δρmin = −0.50 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.

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
Co1	0.25365 (4)	0.21493 (2)	0.11357 (3)	0.02595 (11)
Cl1	0.03672 (8)	0.22325 (5)	0.19158 (8)	0.04536 (18)
Cl2	0.22386 (8)	0.15352 (6)	−0.10586 (7)	0.0524 (2)
N1	0.3503 (2)	0.34291 (13)	0.1133 (2)	0.0328 (5)
N2	0.3658 (2)	0.41178 (14)	0.2134 (2)	0.0326 (4)
N3	0.4134 (2)	0.13497 (14)	0.2583 (2)	0.0366 (5)
N4	0.5304 (3)	0.08313 (15)	0.2309 (2)	0.0395 (5)
C1	0.3155 (3)	0.3991 (2)	0.3455 (3)	0.0450 (7)
H1A	0.3788	0.3510	0.4045	0.068*
H1B	0.2069	0.3801	0.3211	0.068*
H1C	0.3274	0.4577	0.3987	0.068*
C2	0.4355 (3)	0.48681 (16)	0.1747 (3)	0.0340 (5)
H2	0.4604	0.5426	0.2282	0.041*
C3	0.4646 (3)	0.46860 (16)	0.0428 (2)	0.0312 (5)
C4	0.4096 (3)	0.37736 (16)	0.0101 (3)	0.0331 (5)
H4	0.4138	0.3446	−0.0739	0.040*
C5	0.6047 (4)	0.1093 (2)	0.1180 (3)	0.0557 (8)
H5A	0.6626	0.1672	0.1446	0.084*
H5B	0.5256	0.1184	0.0280	0.084*
H5C	0.6754	0.0598	0.1060	0.084*
C6	0.5804 (3)	0.01861 (18)	0.3343 (3)	0.0384 (6)
H6	0.6604	−0.0253	0.3379	0.046*
C7	0.4942 (3)	0.02779 (16)	0.4347 (2)	0.0327 (5)
C8	0.3922 (3)	0.10152 (17)	0.3821 (3)	0.0345 (5)
H8	0.3180	0.1248	0.4278	0.041*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.02900 (18)	0.02089 (16)	0.02955 (17)	−0.00168 (13)	0.01042 (13)	0.00677 (12)
Cl1	0.0422 (4)	0.0449 (4)	0.0548 (4)	−0.0005 (3)	0.0230 (3)	0.0103 (3)
Cl2	0.0480 (4)	0.0623 (5)	0.0464 (4)	−0.0050 (3)	0.0110 (3)	−0.0124 (3)
N1	0.0398 (12)	0.0261 (10)	0.0349 (11)	−0.0013 (9)	0.0140 (9)	0.0029 (8)
N2	0.0363 (11)	0.0310 (10)	0.0330 (11)	0.0005 (9)	0.0133 (9)	0.0014 (8)
N3	0.0362 (12)	0.0352 (11)	0.0401 (12)	0.0019 (9)	0.0128 (10)	0.0069 (9)
N4	0.0352 (12)	0.0428 (12)	0.0428 (12)	0.0031 (10)	0.0143 (10)	0.0089 (10)
C1	0.0551 (17)	0.0470 (16)	0.0393 (15)	−0.0045 (13)	0.0234 (13)	0.0032 (12)
C2	0.0373 (14)	0.0245 (11)	0.0417 (14)	0.0006 (10)	0.0128 (11)	0.0026 (10)
C3	0.0323 (13)	0.0260 (11)	0.0364 (13)	0.0035 (10)	0.0111 (10)	0.0060 (10)
C4	0.0399 (14)	0.0279 (12)	0.0344 (13)	−0.0007 (10)	0.0151 (11)	0.0032 (10)
C5	0.0460 (17)	0.077 (2)	0.0506 (17)	0.0083 (16)	0.0233 (14)	0.0181 (16)
C6	0.0324 (14)	0.0405 (14)	0.0410 (14)	0.0049 (11)	0.0073 (11)	0.0081 (12)
C7	0.0310 (13)	0.0294 (12)	0.0355 (13)	−0.0041 (10)	0.0046 (11)	0.0017 (10)
C8	0.0367 (14)	0.0316 (12)	0.0362 (13)	−0.0009 (11)	0.0111 (11)	0.0053 (10)

Geometric parameters (Å, º)

Co1—N1	2.0143 (19)	C1—H1C	0.9700
Co1—N3	2.053 (2)	C2—C3	1.379 (3)
Co1—Cl2	2.2300 (8)	C2—H2	0.9400
Co1—Cl1	2.2416 (7)	C3—C4	1.395 (3)
N1—C4	1.329 (3)	C3—C3^i	1.460 (4)
N1—N2	1.354 (3)	C4—H4	0.9400
N2—C2	1.334 (3)	C5—H5A	0.9700
N2—C1	1.459 (3)	C5—H5B	0.9700
N3—C8	1.337 (3)	C5—H5C	0.9700
N3—N4	1.354 (3)	C6—C7	1.382 (3)
N4—C6	1.340 (3)	C6—H6	0.9400
N4—C5	1.454 (3)	C7—C8	1.393 (3)
C1—H1A	0.9700	C7—C7^ii	1.462 (4)
C1—H1B	0.9700	C8—H8	0.9400
N1—Co1—N3	106.40 (8)	N2—C2—C3	108.3 (2)
N1—Co1—Cl2	107.48 (6)	N2—C2—H2	125.8
N3—Co1—Cl2	108.24 (6)	C3—C2—H2	125.8
N1—Co1—Cl1	110.82 (6)	C2—C3—C4	104.1 (2)
N3—Co1—Cl1	107.86 (6)	C2—C3—C3^i	127.6 (3)
Cl2—Co1—Cl1	115.64 (3)	C4—C3—C3^i	128.3 (3)
C4—N1—N2	105.86 (18)	N1—C4—C3	111.1 (2)
C4—N1—Co1	125.83 (16)	N1—C4—H4	124.5
N2—N1—Co1	128.30 (15)	C3—C4—H4	124.5
C2—N2—N1	110.64 (19)	N4—C5—H5A	109.5
C2—N2—C1	127.5 (2)	N4—C5—H5B	109.5
N1—N2—C1	121.8 (2)	H5A—C5—H5B	109.5
C8—N3—N4	105.6 (2)	N4—C5—H5C	109.5
C8—N3—Co1	124.51 (17)	H5A—C5—H5C	109.5
N4—N3—Co1	127.01 (15)	H5B—C5—H5C	109.5
C6—N4—N3	110.8 (2)	N4—C6—C7	108.3 (2)
C6—N4—C5	126.8 (2)	N4—C6—H6	125.9
N3—N4—C5	121.5 (2)	C7—C6—H6	125.9
N2—C1—H1A	109.5	C6—C7—C8	104.1 (2)
N2—C1—H1B	109.5	C6—C7—C7^ii	128.0 (3)
H1A—C1—H1B	109.5	C8—C7—C7^ii	127.8 (3)
N2—C1—H1C	109.5	N3—C8—C7	111.2 (2)
H1A—C1—H1C	109.5	N3—C8—H8	124.4
H1B—C1—H1C	109.5	C7—C8—H8	124.4
N3—Co1—N1—C4	105.3 (2)	C8—N3—N4—C5	−169.3 (2)
Cl2—Co1—N1—C4	−10.4 (2)	Co1—N3—N4—C5	29.4 (3)
Cl1—Co1—N1—C4	−137.67 (19)	N1—N2—C2—C3	1.4 (3)
N3—Co1—N1—N2	−76.3 (2)	C1—N2—C2—C3	179.1 (2)
Cl2—Co1—N1—N2	167.92 (18)	N2—C2—C3—C4	−1.1 (3)
Cl1—Co1—N1—N2	40.7 (2)	N2—C2—C3—C3^i	178.3 (3)
C4—N1—N2—C2	−1.0 (3)	N2—N1—C4—C3	0.3 (3)
Co1—N1—N2—C2	−179.65 (16)	Co1—N1—C4—C3	178.98 (16)
C4—N1—N2—C1	−179.0 (2)	C2—C3—C4—N1	0.5 (3)
Co1—N1—N2—C1	2.4 (3)	C3^i—C3—C4—N1	−178.9 (3)
N1—Co1—N3—C8	114.0 (2)	N3—N4—C6—C7	−0.2 (3)
Cl2—Co1—N3—C8	−130.80 (19)	C5—N4—C6—C7	168.8 (3)
Cl1—Co1—N3—C8	−5.0 (2)	N4—C6—C7—C8	0.0 (3)
N1—Co1—N3—N4	−88.1 (2)	N4—C6—C7—C7^ii	179.3 (3)
Cl2—Co1—N3—N4	27.2 (2)	N4—N3—C8—C7	−0.4 (3)
Cl1—Co1—N3—N4	152.95 (18)	Co1—N3—C8—C7	161.45 (17)
C8—N3—N4—C6	0.4 (3)	C6—C7—C8—N3	0.3 (3)
Co1—N3—N4—C6	−160.86 (17)	C7^ii—C7—C8—N3	−179.0 (3)

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

(2) Tetraaquabis(1,1'-dimethyl-4,4'-bipyrazole-κN²)cobalt(II) dichloride–1,1'-dimethyl-4,4'-bipyrazole–water (1/2/2)

Crystal data

[Co(C8H10N4)2(H2O)4]Cl2·2C8H10N4·2H2O	Z = 1
Mr = 886.73	F(000) = 465
Triclinic, P1	Dx = 1.377 Mg m^−3
a = 9.2087 (8) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.1415 (10) Å	Cell parameters from 10321 reflections
c = 12.2523 (10) Å	θ = 2.3–27.7°
α = 63.071 (2)°	µ = 0.59 mm^−1
β = 83.665 (3)°	T = 223 K
γ = 72.592 (2)°	Block, pink
V = 1068.96 (16) Å^3	0.17 × 0.14 × 0.12 mm

Data collection

Siemens SMART CCD area-detector diffractometer	4907 independent reflections
Radiation source: fine-focus sealed tube	4058 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.036
ω scans	θmax = 27.7°, θmin = 2.3°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −11→11
Tmin = 0.934, Tmax = 0.961	k = −14→14
10321 measured reflections	l = −15→15

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.104	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0747P)^2] where P = (Fo^2 + 2Fc^2)/3
4907 reflections	(Δ/σ)max < 0.001
287 parameters	Δρmax = 0.57 e Å^−3
0 restraints	Δρmin = −0.71 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.

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
Co1	0.5000	0.5000	0.5000	0.02044 (10)
Cl1	1.04023 (5)	0.09005 (4)	0.30692 (4)	0.03318 (12)
O1	0.71129 (14)	0.47606 (12)	0.41437 (12)	0.0283 (3)
O2	0.42174 (15)	0.69169 (11)	0.35511 (11)	0.0298 (3)
O3	0.91236 (19)	0.22023 (15)	0.48620 (16)	0.0443 (4)
N1	0.28883 (17)	0.40193 (15)	0.37109 (14)	0.0310 (3)
N2	0.42554 (16)	0.39689 (13)	0.40732 (13)	0.0260 (3)
N3	0.68212 (17)	−0.08771 (15)	0.32178 (15)	0.0318 (3)
N4	0.54352 (17)	−0.09277 (14)	0.30204 (14)	0.0316 (3)
N5	0.2576 (2)	0.75536 (17)	0.04117 (16)	0.0409 (4)
N6	0.27595 (19)	0.77693 (17)	0.13677 (15)	0.0378 (4)
N7	0.75182 (19)	0.69516 (16)	0.05682 (15)	0.0364 (4)
N8	0.7612 (2)	0.57498 (17)	0.15928 (15)	0.0429 (4)
C1	0.1502 (2)	0.5117 (2)	0.3641 (2)	0.0389 (4)
H1A	0.0623	0.4837	0.3582	0.058*
H1B	0.1519	0.5982	0.2923	0.058*
H1C	0.1441	0.5260	0.4370	0.058*
C2	0.3029 (2)	0.29851 (19)	0.33874 (19)	0.0359 (4)
H2	0.2233	0.2818	0.3109	0.043*
C3	0.4523 (2)	0.22210 (16)	0.35323 (15)	0.0274 (3)
C4	0.52392 (19)	0.28633 (16)	0.39638 (16)	0.0277 (3)
H4	0.6287	0.2562	0.4157	0.033*
C5	0.8178 (2)	−0.1930 (2)	0.3178 (2)	0.0426 (5)
H5A	0.7933	−0.2803	0.3418	0.064*
H5B	0.8952	−0.2078	0.3738	0.064*
H5C	0.8556	−0.1615	0.2353	0.064*
C6	0.6731 (2)	0.02356 (19)	0.34198 (19)	0.0354 (4)
H6	0.7553	0.0474	0.3582	0.042*
C7	0.52119 (19)	0.09595 (16)	0.33442 (16)	0.0274 (3)
C8	0.4461 (2)	0.01877 (17)	0.30994 (17)	0.0312 (4)
H8	0.3398	0.0424	0.3002	0.037*
C9	0.3637 (3)	0.6371 (3)	0.0250 (3)	0.0612 (7)
H9A	0.4491	0.5953	0.0828	0.092*
H9B	0.4004	0.6702	−0.0578	0.092*
H9C	0.3117	0.5675	0.0395	0.092*
C10	0.1360 (2)	0.8506 (2)	−0.03049 (19)	0.0403 (4)
H10	0.1036	0.8553	−0.1028	0.048*
C11	0.0679 (2)	0.93976 (18)	0.02133 (16)	0.0321 (4)
C12	0.1604 (2)	0.88967 (18)	0.12550 (17)	0.0337 (4)
H12	0.1435	0.9299	0.1803	0.040*
C13	0.6411 (3)	0.8260 (2)	0.0424 (2)	0.0488 (5)
H13A	0.5860	0.8111	0.1176	0.073*
H13B	0.5701	0.8578	−0.0244	0.073*
H13C	0.6933	0.8964	0.0246	0.073*
C14	0.8551 (2)	0.67443 (19)	−0.02418 (17)	0.0370 (4)
H14	0.8691	0.7430	−0.1022	0.044*
C15	0.9370 (2)	0.53470 (19)	0.02742 (16)	0.0339 (4)
C16	0.8737 (2)	0.4786 (2)	0.14113 (19)	0.0426 (5)
H16	0.9063	0.3839	0.1986	0.051*
H1W	0.773 (3)	0.393 (3)	0.437 (2)	0.051 (7)*
H2W	0.706 (3)	0.512 (3)	0.332 (2)	0.051 (7)*
H3W	0.463 (2)	0.761 (2)	0.3386 (17)	0.026 (5)*
H4W	0.390 (3)	0.697 (3)	0.289 (3)	0.067 (8)*
H5W	0.907 (3)	0.151 (3)	0.544 (3)	0.056 (8)*
H6W	0.949 (4)	0.191 (3)	0.440 (3)	0.072 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.02779 (17)	0.01031 (14)	0.02518 (16)	−0.00510 (11)	−0.00202 (11)	−0.00906 (11)
Cl1	0.0366 (2)	0.0279 (2)	0.0352 (2)	−0.01064 (17)	0.00161 (17)	−0.01334 (17)
O1	0.0324 (6)	0.0178 (5)	0.0348 (7)	−0.0041 (5)	0.0025 (5)	−0.0138 (5)
O2	0.0459 (7)	0.0152 (5)	0.0293 (6)	−0.0127 (5)	−0.0096 (5)	−0.0059 (4)
O3	0.0567 (10)	0.0249 (7)	0.0402 (8)	0.0017 (6)	0.0007 (7)	−0.0130 (6)
N1	0.0309 (8)	0.0247 (7)	0.0452 (9)	−0.0057 (6)	−0.0046 (6)	−0.0222 (6)
N2	0.0273 (7)	0.0209 (6)	0.0340 (7)	−0.0076 (5)	−0.0035 (6)	−0.0142 (5)
N3	0.0302 (7)	0.0242 (7)	0.0492 (9)	−0.0083 (6)	0.0007 (6)	−0.0226 (6)
N4	0.0381 (8)	0.0232 (7)	0.0436 (8)	−0.0142 (6)	0.0015 (6)	−0.0199 (6)
N5	0.0440 (9)	0.0345 (8)	0.0466 (10)	−0.0013 (7)	−0.0109 (7)	−0.0234 (7)
N6	0.0428 (9)	0.0330 (8)	0.0361 (8)	−0.0056 (7)	−0.0112 (7)	−0.0145 (7)
N7	0.0412 (9)	0.0268 (7)	0.0353 (8)	−0.0079 (6)	0.0083 (7)	−0.0114 (6)
N8	0.0506 (10)	0.0305 (8)	0.0367 (9)	−0.0082 (7)	0.0100 (7)	−0.0096 (7)
C1	0.0331 (9)	0.0317 (9)	0.0574 (12)	−0.0023 (7)	−0.0064 (8)	−0.0269 (9)
C2	0.0359 (10)	0.0313 (9)	0.0556 (12)	−0.0121 (7)	−0.0019 (8)	−0.0294 (9)
C3	0.0349 (9)	0.0183 (7)	0.0341 (9)	−0.0100 (6)	−0.0001 (7)	−0.0141 (6)
C4	0.0295 (8)	0.0215 (7)	0.0358 (9)	−0.0057 (6)	−0.0047 (7)	−0.0154 (7)
C5	0.0371 (10)	0.0321 (10)	0.0663 (14)	−0.0053 (8)	0.0001 (9)	−0.0307 (10)
C6	0.0356 (10)	0.0295 (9)	0.0555 (12)	−0.0151 (7)	0.0017 (8)	−0.0273 (8)
C7	0.0330 (9)	0.0205 (7)	0.0359 (9)	−0.0118 (6)	0.0045 (7)	−0.0168 (7)
C8	0.0274 (8)	0.0241 (8)	0.0495 (10)	−0.0082 (6)	−0.0053 (7)	−0.0207 (7)
C9	0.0606 (15)	0.0462 (13)	0.0838 (18)	0.0099 (11)	−0.0179 (13)	−0.0456 (13)
C10	0.0414 (11)	0.0399 (10)	0.0404 (10)	−0.0025 (8)	−0.0121 (8)	−0.0210 (8)
C11	0.0385 (10)	0.0262 (8)	0.0297 (8)	−0.0099 (7)	−0.0062 (7)	−0.0088 (7)
C12	0.0392 (10)	0.0280 (8)	0.0334 (9)	−0.0063 (7)	−0.0081 (7)	−0.0132 (7)
C13	0.0564 (13)	0.0317 (10)	0.0492 (12)	−0.0052 (9)	0.0114 (10)	−0.0168 (9)
C14	0.0456 (11)	0.0309 (9)	0.0313 (9)	−0.0130 (8)	0.0107 (8)	−0.0119 (7)
C15	0.0382 (10)	0.0324 (9)	0.0325 (9)	−0.0130 (8)	0.0049 (7)	−0.0145 (7)
C16	0.0515 (12)	0.0304 (9)	0.0374 (10)	−0.0091 (8)	0.0092 (9)	−0.0111 (8)

Geometric parameters (Å, º)

Co1—O2^i	2.0395 (11)	C1—H1C	0.9700
Co1—O2	2.0395 (11)	C2—C3	1.366 (3)
Co1—O1^i	2.1095 (12)	C2—H2	0.9400
Co1—O1	2.1095 (12)	C3—C4	1.389 (2)
Co1—N2^i	2.2145 (13)	C3—C7	1.469 (2)
Co1—N2	2.2145 (13)	C4—H4	0.9400
O1—H1W	0.86 (3)	C5—H5A	0.9700
O1—H2W	0.91 (3)	C5—H5B	0.9700
O2—H3W	0.89 (2)	C5—H5C	0.9700
O2—H4W	0.86 (3)	C6—C7	1.379 (2)
O3—H5W	0.78 (3)	C6—H6	0.9400
O3—H6W	0.77 (3)	C7—C8	1.394 (2)
N1—C2	1.3471 (19)	C8—H8	0.9400
N1—N2	1.3578 (19)	C9—H9A	0.9700
N1—C1	1.459 (2)	C9—H9B	0.9700
N2—C4	1.3457 (19)	C9—H9C	0.9700
N3—N4	1.347 (2)	C10—C11	1.376 (3)
N3—C6	1.348 (2)	C10—H10	0.9400
N3—C5	1.449 (2)	C11—C12	1.406 (2)
N4—C8	1.335 (2)	C11—C11^ii	1.464 (3)
N5—N6	1.335 (2)	C12—H12	0.9400
N5—C10	1.346 (2)	C13—H13A	0.9700
N5—C9	1.467 (2)	C13—H13B	0.9700
N6—C12	1.343 (2)	C13—H13C	0.9700
N7—N8	1.345 (2)	C14—C15	1.379 (3)
N7—C14	1.346 (2)	C14—H14	0.9400
N7—C13	1.453 (2)	C15—C16	1.386 (3)
N8—C16	1.333 (2)	C15—C15^iii	1.469 (3)
C1—H1A	0.9700	C16—H16	0.9400
C1—H1B	0.9700
O2^i—Co1—O2	180	C2—C3—C7	128.21 (15)
O2^i—Co1—O1^i	88.76 (5)	C4—C3—C7	127.50 (16)
O2—Co1—O1^i	91.24 (5)	N2—C4—C3	111.98 (15)
O2^i—Co1—O1	91.24 (5)	N2—C4—H4	124.0
O2—Co1—O1	88.76 (5)	C3—C4—H4	124.0
O1^i—Co1—O1	180	N3—C5—H5A	109.5
O2^i—Co1—N2^i	91.07 (5)	N3—C5—H5B	109.5
O2—Co1—N2^i	88.93 (5)	H5A—C5—H5B	109.5
O1^i—Co1—N2^i	89.16 (5)	N3—C5—H5C	109.5
O1—Co1—N2^i	90.84 (5)	H5A—C5—H5C	109.5
O2^i—Co1—N2	88.93 (5)	H5B—C5—H5C	109.5
O2—Co1—N2	91.07 (5)	N3—C6—C7	107.36 (15)
O1^i—Co1—N2	90.84 (5)	N3—C6—H6	126.3
O1—Co1—N2	89.16 (5)	C7—C6—H6	126.3
N2^i—Co1—N2	180	C6—C7—C8	104.31 (14)
Co1—O1—H1W	118.9 (16)	C6—C7—C3	128.24 (15)
Co1—O1—H2W	115.6 (16)	C8—C7—C3	127.40 (16)
H1W—O1—H2W	104 (2)	N4—C8—C7	111.67 (15)
Co1—O2—H3W	121.0 (13)	N4—C8—H8	124.2
Co1—O2—H4W	119.8 (19)	C7—C8—H8	124.2
H3W—O2—H4W	111 (2)	N5—C9—H9A	109.5
H5W—O3—H6W	101 (3)	N5—C9—H9B	109.5
C2—N1—N2	110.98 (14)	H9A—C9—H9B	109.5
C2—N1—C1	126.63 (15)	N5—C9—H9C	109.5
N2—N1—C1	122.32 (13)	H9A—C9—H9C	109.5
C4—N2—N1	104.34 (12)	H9B—C9—H9C	109.5
C4—N2—Co1	119.94 (11)	N5—C10—C11	107.57 (16)
N1—N2—Co1	134.76 (10)	N5—C10—H10	126.2
N4—N3—C6	111.68 (14)	C11—C10—H10	126.2
N4—N3—C5	120.34 (13)	C10—C11—C12	103.89 (16)
C6—N3—C5	127.97 (16)	C10—C11—C11^ii	128.8 (2)
C8—N4—N3	104.97 (12)	C12—C11—C11^ii	127.3 (2)
N6—N5—C10	112.35 (15)	N6—C12—C11	111.36 (16)
N6—N5—C9	119.95 (17)	N6—C12—H12	124.3
C10—N5—C9	127.69 (17)	C11—C12—H12	124.3
N5—N6—C12	104.81 (15)	N7—C13—H13A	109.5
N8—N7—C14	111.01 (15)	N7—C13—H13B	109.5
N8—N7—C13	121.53 (16)	H13A—C13—H13B	109.5
C14—N7—C13	127.47 (16)	N7—C13—H13C	109.5
C16—N8—N7	105.23 (15)	H13A—C13—H13C	109.5
N1—C1—H1A	109.5	H13B—C13—H13C	109.5
N1—C1—H1B	109.5	N7—C14—C15	107.93 (16)
H1A—C1—H1B	109.5	N7—C14—H14	126.0
N1—C1—H1C	109.5	C15—C14—H14	126.0
H1A—C1—H1C	109.5	C14—C15—C16	103.89 (16)
H1B—C1—H1C	109.5	C14—C15—C15^iii	126.9 (2)
N1—C2—C3	108.50 (15)	C16—C15—C15^iii	129.2 (2)
N1—C2—H2	125.8	N8—C16—C15	111.94 (17)
C3—C2—H2	125.8	N8—C16—H16	124.0
C2—C3—C4	104.20 (13)	C15—C16—H16	124.0
C2—N1—N2—C4	−0.2 (2)	N4—N3—C6—C7	−0.4 (2)
C1—N1—N2—C4	−177.33 (17)	C5—N3—C6—C7	178.60 (18)
C2—N1—N2—Co1	−168.43 (13)	N3—C6—C7—C8	0.4 (2)
C1—N1—N2—Co1	14.4 (3)	N3—C6—C7—C3	177.95 (17)
O2^i—Co1—N2—C4	−51.45 (13)	C2—C3—C7—C6	175.8 (2)
O2—Co1—N2—C4	128.55 (13)	C4—C3—C7—C6	−8.0 (3)
O1^i—Co1—N2—C4	−140.20 (13)	C2—C3—C7—C8	−7.3 (3)
O1—Co1—N2—C4	39.80 (13)	C4—C3—C7—C8	168.92 (18)
O2^i—Co1—N2—N1	115.38 (16)	N3—N4—C8—C7	0.1 (2)
O2—Co1—N2—N1	−64.62 (16)	C6—C7—C8—N4	−0.4 (2)
O1^i—Co1—N2—N1	26.64 (15)	C3—C7—C8—N4	−177.89 (17)
O1—Co1—N2—N1	−153.36 (15)	N6—N5—C10—C11	−0.9 (3)
C6—N3—N4—C8	0.2 (2)	C9—N5—C10—C11	178.5 (2)
C5—N3—N4—C8	−178.92 (17)	N5—C10—C11—C12	0.8 (2)
C10—N5—N6—C12	0.5 (2)	N5—C10—C11—C11^ii	−179.8 (2)
C9—N5—N6—C12	−178.9 (2)	N5—N6—C12—C11	0.0 (2)
C14—N7—N8—C16	0.5 (2)	C10—C11—C12—N6	−0.5 (2)
C13—N7—N8—C16	−179.6 (2)	C11^ii—C11—C12—N6	−179.9 (2)
N2—N1—C2—C3	−0.1 (2)	N8—N7—C14—C15	−0.5 (2)
C1—N1—C2—C3	176.90 (18)	C13—N7—C14—C15	179.7 (2)
N1—C2—C3—C4	0.3 (2)	N7—C14—C15—C16	0.2 (2)
N1—C2—C3—C7	177.22 (17)	N7—C14—C15—C15^iii	−179.1 (2)
N1—N2—C4—C3	0.40 (19)	N7—N8—C16—C15	−0.4 (2)
Co1—N2—C4—C3	170.79 (11)	C14—C15—C16—N8	0.2 (2)
C2—C3—C4—N2	−0.5 (2)	C15^iii—C15—C16—N8	179.4 (3)
C7—C3—C4—N2	−177.38 (16)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1W···O3	0.86 (3)	1.84 (3)	2.6939 (18)	177 (2)
O1—H2W···N8	0.91 (3)	1.96 (3)	2.839 (2)	163 (2)
O2—H3W···N4^iv	0.89 (2)	1.84 (2)	2.7356 (18)	179 (2)
O2—H4W···N6	0.86 (3)	1.94 (3)	2.755 (2)	159 (3)
O3—H5W···Cl1^v	0.78 (3)	2.40 (3)	3.1576 (17)	162 (3)
O3—H6W···Cl1	0.77 (3)	2.33 (3)	3.0997 (17)	174 (3)
C6—H6···Cl1	0.94	2.76	3.6126 (19)	151
C8—H8···Cl1^vi	0.94	2.65	3.5814 (18)	172
C10—H10···Cl1^vii	0.94	2.69	3.617 (2)	168
C12—H12···Cl1^viii	0.94	2.77	3.6911 (18)	167
C14—H14···Cl1^iii	0.94	2.59	3.5153 (19)	170
C16—H16···Cl1	0.94	2.83	3.738 (2)	163

Symmetry codes: (iii) −x+2, −y+1, −z; (iv) x, y+1, z; (v) −x+2, −y, −z+1; (vi) x−1, y, z; (vii) −x+1, −y+1, −z; (viii) x−1, y+1, z.