[2,6-Bis(3,5-di­methyl­pyrazol-1-yl­methyl-[kappa]N²)­pyridine-[kappa]N]bis­(thiocyanato-N)copper(II)

The title compound, [Cu(NCS)₂(C₁₇H₂₁N₅)], displays a distorted square-pyramidal coordination geometry, where the basal plane is defined by the tridentate ligand and by one of the thio­cyanate ions. The apical position is occupied by the other thio­cyanate ion.

S1. Comment

The spectroscopic and chemical properties of copper compounds of pyrazole and its derivatives have been studied intensively during the last two decades (Sheu et al., 1995; Martens et al., 1995; Kitajima et al., 1992; Sorrel et al., 1991) because of their ease of handling and manipulation in making model compounds for biological systems such as haemocyanin and tyrosinase (Solomon et al., 1992). To give more insight into the coordination behaviour of pyrazole based ligands with copper(I) and copper(II) ions, a systematic study has been embarked on in our group (Manikandan et al., 1996, 1998) of the ligand 2,6-bis(3,5-dimethylpyrazol-1-ylmethyl)pyridine, L, containing one pyridine and two pyrazole donors. Herein, we report the crystal structure of (I), a monomeric copper(II) complex with the ligand L and thiocyanate counter ions. \scheme

The structure of (I) (Fig. 1) consists of a pentacoordinated Cu²⁺ ion in a distorted square pyramidal geometry, with the three N atoms from the ligand and an N from one of the thiocyanate groups occupying the basal plane. The axial position is occupied by the second thiocyanate N atom. The axial Cu—NCS bond distance is slightly longer (by ca 0.16 Å) than the corresponding equatorial bond (Table 1). The Cu²⁺ ion is displaced 0.308 Å above the plane formed by N1/N2/N3/N7. The significant deviation of the basal plane is evident also from the angles N1—Cu—N2 and N3—Cu—N7, with values of 169.10 (12) and 153.74 (14)°, respectively. The pyridine and pyrazole rings are planar. The geometries of the two linear thiocyanate ligands are similar, but they differ notably in the angles they make to the copper nucleus [177.7 (4) and 153.4 (3)°]. This dissimilarity destroys the approximate twofold rotational symmetry of the compound.

In order to quantify the distortion of the coordination polyhedron in (I), we have calculated the dihedral angles between the polyhedral faces, and thus the parameters Δ and τ, by following the methods described by Meutterties & Guggenberger (1974) and Addison et al. (1984). The parameters Δ and τ describe the deviation from trigonal bipyramidal geometry and trigonality, respectively. For the regular square pyramid structure, the trigonality parameter, τ, will be zero, and it increases to 1.0 as the trigonal bipyramidal distortion increases. Similarly, Δ is zero for trigonal bipyramidal compounds and increases to 1.0 for square pyramidal geometry. The calculated Δ and τ values for (I) are 0.706 and 0.256, respectively, indicating more trigonal distortion from ideal square pyramidal geometry.

S2. Experimental

2,6-Bis(3,5-dimethylpyrazol-1-ylmethyl)pyridine (L) was prepared using the procedure of Manikandan et al. (1996). To a solution of L (0.295 g) in methanol (30 ml) was added Cu(ClO₄)₂·6H₂O (0.37 g) followed by NH₄NCS (0.076 g) with vigorous stirring. A green precipitate was formed. The mixture was allowed to stir for a further 1 h to ensure complete conversion and was then filtered. The residue was washed with cold methanol/water mixture (1:1) and recrystallized from acetonitrile. Analysis found: C 47.75, H 4.55, N 20.50%; C₁₉H₂₁N₇S₂Cu requires: C 48.03, H 4.46, N 20.64%.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP (Zsolnai & Pritzkow, 1994); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. The molecular structure of (I), showing 40% probability displacement ellipsoids. H atoms are omitted for clarity.

[2,6-Bis(3,5-dimethylpyrazol-1-ylmethyl-κN²)pyridine-κN] bis(thiocyanato-N)copper(II)

Crystal data

[Cu(CNS)2(C17H21N5)]	F(000) = 980
Mr = 475.09	Dx = 1.478 Mg m^−3
Monoclinic, P21/n	Cu Kα radiation, λ = 1.54184 Å
a = 11.382 (5) Å	Cell parameters from 25 reflections
b = 12.162 (4) Å	θ = 12–15°
c = 15.855 (7) Å	µ = 3.44 mm^−1
β = 103.31 (3)°	T = 293 K
V = 2135.8 (14) Å^3	Prism, dark green
Z = 4	0.32 × 0.25 × 0.20 mm

Data collection

Enraf-Nonius CAD4 diffractometer	2649 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.032
Graphite monochromator	θmax = 59.9°, θmin = 4.3°
ω/2θ scans	h = 0→12
Absorption correction: ψ-scan (North et al., 1968)	k = 0→13
Tmin = 0.337, Tmax = 0.503	l = −17→17
3237 measured reflections	3 standard reflections every 60 min
3057 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.047	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.135	Calculated w = 1/[σ^2(Fo^2) + (0.0979P)^2 + 1.322P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.002
3057 reflections	Δρmax = 0.56 e Å^−3
267 parameters	Δρmin = −0.52 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0017 (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
Cu	0.22034 (4)	0.21151 (3)	0.94312 (3)	0.0340 (2)
S1	0.54076 (10)	0.27441 (9)	0.81456 (7)	0.0639 (3)
S2	−0.13722 (11)	0.27926 (10)	0.71033 (8)	0.0797 (4)
N1	0.1921 (2)	0.3436 (2)	1.01509 (17)	0.0377 (6)
N2	0.2628 (2)	0.0659 (2)	0.89347 (16)	0.0388 (6)
N3	0.1595 (2)	0.1181 (2)	1.03371 (15)	0.0335 (6)
N4	0.0876 (2)	0.3453 (2)	1.04424 (17)	0.0402 (6)
N5	0.3095 (2)	−0.0181 (2)	0.94761 (16)	0.0377 (6)
N6	0.0659 (3)	0.2461 (2)	0.8419 (2)	0.0494 (7)
N7	0.3468 (3)	0.2804 (2)	0.8941 (2)	0.0524 (8)
C1	0.0597 (3)	0.1496 (3)	1.0601 (2)	0.0378 (7)
C2	0.0166 (3)	0.0888 (3)	1.1203 (2)	0.0486 (9)
H2	−0.0536	0.1100	1.1364	0.058*
C3	0.0779 (4)	−0.0025 (3)	1.1557 (2)	0.0586 (11)
H3	0.0501	−0.0433	1.1968	0.070*
C4	0.1805 (4)	−0.0346 (3)	1.1309 (2)	0.0492 (9)
H4	0.2233	−0.0964	1.1551	0.059*
C5	0.2187 (3)	0.0278 (3)	1.06890 (18)	0.0362 (7)
C6	0.3329 (3)	0.0003 (3)	1.04103 (19)	0.0404 (8)
H6A	0.3901	0.0601	1.0568	0.048*
H6B	0.3687	−0.0653	1.0711	0.048*
C7	0.3311 (3)	−0.1072 (3)	0.9035 (2)	0.0445 (8)
C8	0.2976 (3)	−0.0800 (3)	0.8175 (2)	0.0484 (9)
H8	0.3019	−0.1249	0.7708	0.058*
C9	0.2560 (3)	0.0271 (3)	0.8135 (2)	0.0407 (8)
C10	0.3812 (5)	−0.2115 (3)	0.9458 (3)	0.0736 (14)
H10A	0.4581	−0.1974	0.9843	0.110*
H10B	0.3912	−0.2634	0.9024	0.110*
H10C	0.3268	−0.2411	0.9781	0.110*
C11	0.2096 (4)	0.0941 (3)	0.7337 (2)	0.0575 (10)
H11A	0.1248	0.1074	0.7273	0.086*
H11B	0.2222	0.0548	0.6841	0.086*
H11C	0.2518	0.1629	0.7387	0.086*
C12	0.0022 (3)	0.2553 (3)	1.0236 (2)	0.0439 (8)
H12A	−0.0255	0.2488	0.9612	0.053*
H12B	−0.0674	0.2704	1.0474	0.053*
C13	0.2542 (3)	0.4326 (3)	1.0501 (2)	0.0430 (8)
C14	0.1892 (4)	0.4896 (3)	1.0998 (2)	0.0509 (9)
H14	0.2124	0.5546	1.1300	0.061*
C15	0.0853 (3)	0.4329 (3)	1.0965 (2)	0.0452 (8)
C16	0.3757 (4)	0.4604 (3)	1.0362 (3)	0.0612 (10)
H16A	0.4287	0.3986	1.0520	0.092*
H16B	0.4077	0.5226	1.0714	0.092*
H16C	0.3691	0.4779	0.9763	0.092*
C17	−0.0173 (4)	0.4548 (3)	1.1383 (3)	0.0630 (11)
H17A	−0.0914	0.4574	1.0947	0.094*
H17B	−0.0048	0.5239	1.1683	0.094*
H17C	−0.0218	0.3971	1.1787	0.094*
C18	0.4273 (4)	0.2781 (3)	0.8602 (2)	0.0442 (8)
C19	−0.0178 (3)	0.2614 (3)	0.7869 (2)	0.0387 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu	0.0339 (3)	0.0318 (3)	0.0364 (3)	0.00077 (18)	0.0084 (2)	0.00114 (17)
S1	0.0650 (7)	0.0783 (7)	0.0566 (6)	−0.0103 (6)	0.0307 (5)	0.0010 (5)
S2	0.0695 (8)	0.0763 (8)	0.0725 (8)	0.0029 (6)	−0.0265 (6)	0.0169 (6)
N1	0.0320 (14)	0.0345 (14)	0.0471 (15)	0.0003 (12)	0.0103 (11)	0.0008 (12)
N2	0.0444 (15)	0.0382 (14)	0.0346 (13)	0.0048 (12)	0.0110 (11)	0.0026 (11)
N3	0.0360 (14)	0.0294 (13)	0.0348 (13)	−0.0036 (11)	0.0078 (11)	−0.0027 (10)
N4	0.0393 (15)	0.0337 (15)	0.0495 (15)	0.0043 (12)	0.0143 (12)	0.0020 (12)
N5	0.0398 (15)	0.0354 (14)	0.0361 (13)	0.0087 (12)	0.0054 (11)	−0.0003 (11)
N6	0.0487 (17)	0.0431 (16)	0.0518 (17)	0.0050 (14)	0.0024 (15)	−0.0009 (14)
N7	0.0539 (19)	0.0532 (19)	0.0545 (18)	−0.0108 (15)	0.0214 (16)	−0.0027 (14)
C1	0.0359 (17)	0.0364 (17)	0.0422 (17)	−0.0079 (14)	0.0114 (14)	−0.0084 (14)
C2	0.055 (2)	0.043 (2)	0.055 (2)	−0.0173 (18)	0.0263 (17)	−0.0108 (17)
C3	0.087 (3)	0.041 (2)	0.057 (2)	−0.019 (2)	0.035 (2)	−0.0002 (17)
C4	0.072 (3)	0.0334 (18)	0.0422 (18)	−0.0063 (17)	0.0144 (17)	0.0013 (14)
C5	0.0429 (18)	0.0306 (16)	0.0322 (15)	−0.0053 (14)	0.0030 (13)	−0.0047 (13)
C6	0.0426 (18)	0.0379 (17)	0.0360 (16)	0.0070 (15)	−0.0004 (14)	−0.0016 (14)
C7	0.0436 (19)	0.0406 (18)	0.0470 (19)	0.0107 (16)	0.0056 (15)	−0.0053 (15)
C8	0.053 (2)	0.051 (2)	0.0416 (18)	0.0108 (17)	0.0099 (15)	−0.0124 (16)
C9	0.0399 (18)	0.0445 (19)	0.0396 (17)	0.0035 (15)	0.0132 (14)	−0.0032 (14)
C10	0.097 (4)	0.053 (3)	0.063 (3)	0.035 (2)	0.003 (2)	−0.0066 (19)
C11	0.073 (3)	0.062 (2)	0.0386 (18)	0.013 (2)	0.0151 (17)	0.0032 (17)
C12	0.0328 (17)	0.048 (2)	0.053 (2)	−0.0001 (16)	0.0141 (15)	−0.0015 (17)
C13	0.0446 (18)	0.0335 (18)	0.0478 (18)	−0.0013 (15)	0.0039 (15)	−0.0011 (14)
C14	0.067 (2)	0.0314 (17)	0.055 (2)	−0.0007 (18)	0.0148 (18)	−0.0063 (16)
C15	0.056 (2)	0.0340 (18)	0.0466 (18)	0.0139 (17)	0.0147 (16)	0.0021 (14)
C16	0.052 (2)	0.048 (2)	0.085 (3)	−0.0140 (19)	0.018 (2)	−0.013 (2)
C17	0.079 (3)	0.050 (2)	0.070 (3)	0.015 (2)	0.038 (2)	0.0027 (19)
C18	0.049 (2)	0.041 (2)	0.0419 (18)	−0.0104 (16)	0.0095 (17)	0.0008 (14)
C19	0.045 (2)	0.0314 (16)	0.0393 (17)	0.0018 (15)	0.0078 (16)	0.0046 (14)

Geometric parameters (Å, º)

Cu—N7	1.974 (3)	N6—C19	1.150 (5)
Cu—N1	2.038 (3)	N7—C18	1.164 (5)
Cu—N2	2.041 (3)	C1—C2	1.383 (5)
Cu—N3	2.071 (3)	C1—C12	1.497 (5)
Cu—N6	2.131 (3)	C2—C3	1.362 (6)
S1—C18	1.620 (4)	C3—C4	1.371 (6)
S2—C19	1.615 (4)	C4—C5	1.389 (5)
N1—C13	1.341 (4)	C5—C6	1.504 (5)
N1—N4	1.372 (4)	C7—C8	1.369 (5)
N2—C9	1.338 (4)	C7—C10	1.486 (5)
N2—N5	1.361 (4)	C8—C9	1.383 (5)
N3—C5	1.342 (4)	C9—C11	1.495 (5)
N3—C1	1.354 (4)	C13—C14	1.384 (5)
N4—C15	1.354 (4)	C13—C16	1.489 (5)
N4—C12	1.451 (4)	C14—C15	1.360 (5)
N5—C7	1.343 (4)	C15—C17	1.493 (5)
N5—C6	1.460 (4)
N7—Cu—N1	96.27 (12)	N3—C1—C2	121.2 (3)
N7—Cu—N2	87.54 (12)	N3—C1—C12	116.5 (3)
N1—Cu—N2	169.02 (10)	C2—C1—C12	122.2 (3)
N7—Cu—N3	153.71 (13)	C3—C2—C1	119.5 (3)
N1—Cu—N3	85.59 (10)	C2—C3—C4	120.1 (3)
N2—Cu—N3	86.47 (10)	C3—C4—C5	118.3 (3)
N7—Cu—N6	99.78 (14)	N3—C5—C4	122.2 (3)
N1—Cu—N6	93.28 (11)	N3—C5—C6	116.4 (3)
N2—Cu—N6	96.22 (11)	C4—C5—C6	121.3 (3)
N3—Cu—N6	106.31 (12)	N5—C6—C5	111.3 (2)
C13—N1—N4	105.2 (3)	N5—C7—C8	106.3 (3)
C13—N1—Cu	137.1 (2)	N5—C7—C10	123.4 (3)
N4—N1—Cu	117.47 (19)	C8—C7—C10	130.2 (3)
C9—N2—N5	105.2 (3)	C7—C8—C9	106.7 (3)
C9—N2—Cu	134.8 (2)	N2—C9—C8	110.1 (3)
N5—N2—Cu	120.03 (18)	N2—C9—C11	122.8 (3)
C5—N3—C1	118.7 (3)	C8—C9—C11	127.0 (3)
C5—N3—Cu	121.5 (2)	N4—C12—C1	110.5 (3)
C1—N3—Cu	119.8 (2)	N1—C13—C14	109.9 (3)
C15—N4—N1	111.1 (3)	N1—C13—C16	122.7 (3)
C15—N4—C12	128.7 (3)	C14—C13—C16	127.4 (3)
N1—N4—C12	120.0 (3)	C15—C14—C13	107.4 (3)
C7—N5—N2	111.6 (2)	N4—C15—C14	106.4 (3)
C7—N5—C6	129.7 (3)	N4—C15—C17	122.6 (3)
N2—N5—C6	118.6 (2)	C14—C15—C17	131.0 (3)
C19—N6—Cu	178.0 (3)	N7—C18—S1	179.1 (4)
C18—N7—Cu	153.4 (3)	N6—C19—S2	178.2 (3)
N7—Cu—N1—C13	−23.2 (3)	N3—C1—C2—C3	2.2 (5)
N2—Cu—N1—C13	86.6 (6)	C12—C1—C2—C3	−175.4 (3)
N3—Cu—N1—C13	130.4 (3)	C1—C2—C3—C4	−0.9 (5)
N6—Cu—N1—C13	−123.5 (3)	C2—C3—C4—C5	−0.5 (5)
N7—Cu—N1—N4	163.0 (2)	C1—N3—C5—C4	0.4 (4)
N2—Cu—N1—N4	−87.1 (6)	Cu—N3—C5—C4	178.7 (2)
N3—Cu—N1—N4	−43.3 (2)	C1—N3—C5—C6	−176.6 (3)
N6—Cu—N1—N4	62.8 (2)	Cu—N3—C5—C6	1.8 (3)
N7—Cu—N2—C9	−64.5 (3)	C3—C4—C5—N3	0.8 (5)
N1—Cu—N2—C9	−175.2 (5)	C3—C4—C5—C6	177.6 (3)
N3—Cu—N2—C9	141.1 (3)	C7—N5—C6—C5	−121.5 (3)
N6—Cu—N2—C9	35.0 (3)	N2—N5—C6—C5	61.2 (4)
N7—Cu—N2—N5	115.7 (2)	N3—C5—C6—N5	−60.1 (3)
N1—Cu—N2—N5	5.0 (7)	C4—C5—C6—N5	122.9 (3)
N3—Cu—N2—N5	−38.7 (2)	N2—N5—C7—C8	0.2 (4)
N6—Cu—N2—N5	−144.8 (2)	C6—N5—C7—C8	−177.2 (3)
N7—Cu—N3—C5	−37.9 (4)	N2—N5—C7—C10	−179.5 (4)
N1—Cu—N3—C5	−133.1 (2)	C6—N5—C7—C10	3.0 (6)
N2—Cu—N3—C5	39.3 (2)	N5—C7—C8—C9	−0.1 (4)
N6—Cu—N3—C5	134.7 (2)	C10—C7—C8—C9	179.6 (4)
N7—Cu—N3—C1	140.4 (3)	N5—N2—C9—C8	0.2 (4)
N1—Cu—N3—C1	45.2 (2)	Cu—N2—C9—C8	−179.6 (2)
N2—Cu—N3—C1	−142.4 (2)	N5—N2—C9—C11	−179.7 (3)
N6—Cu—N3—C1	−47.0 (2)	Cu—N2—C9—C11	0.5 (5)
C13—N1—N4—C15	−0.4 (3)	C7—C8—C9—N2	−0.1 (4)
Cu—N1—N4—C15	175.2 (2)	C7—C8—C9—C11	179.8 (4)
C13—N1—N4—C12	−175.5 (3)	C15—N4—C12—C1	−113.3 (4)
Cu—N1—N4—C12	0.0 (4)	N1—N4—C12—C1	61.0 (4)
C9—N2—N5—C7	−0.2 (4)	N3—C1—C12—N4	−58.4 (4)
Cu—N2—N5—C7	179.6 (2)	C2—C1—C12—N4	119.3 (3)
C9—N2—N5—C6	177.5 (3)	N4—N1—C13—C14	−0.4 (4)
Cu—N2—N5—C6	−2.6 (4)	Cu—N1—C13—C14	−174.6 (2)
N7—Cu—N6—C19	115 (8)	N4—N1—C13—C16	178.6 (3)
N1—Cu—N6—C19	−149 (8)	Cu—N1—C13—C16	4.4 (5)
N2—Cu—N6—C19	26 (8)	N1—C13—C14—C15	1.0 (4)
N3—Cu—N6—C19	−62 (8)	C16—C13—C14—C15	−177.9 (4)
N1—Cu—N7—C18	161.7 (7)	N1—N4—C15—C14	1.0 (4)
N2—Cu—N7—C18	−8.0 (7)	C12—N4—C15—C14	175.7 (3)
N3—Cu—N7—C18	68.9 (8)	N1—N4—C15—C17	−179.3 (3)
N6—Cu—N7—C18	−103.9 (7)	C12—N4—C15—C17	−4.7 (5)
C5—N3—C1—C2	−1.9 (4)	C13—C14—C15—N4	−1.2 (4)
Cu—N3—C1—C2	179.8 (2)	C13—C14—C15—C17	179.1 (4)
C5—N3—C1—C12	175.8 (3)	Cu—N7—C18—S1	−83 (19)
Cu—N3—C1—C12	−2.6 (4)	Cu—N6—C19—S2	33 (18)