Dimeth­yl(2,2′:6′,2′′-terpyridine-κ³ N,N′,N′′)zinc(II)

Abstract

The title compound, [Zn(CH₃)₂(C₁₅H₁₁N₃)], was synthesized by the addition of dimethyl­zinc to 2,2′:6′,2′′-terpyridine and was crystallized by the slow evaporation of THF. The penta­coordinate Zn^II atom, lying on a twofold rotation axis, displays a distorted trigonal-bipyramidal geometry, with two terminal N atoms at the axial positions and the central N atom and two methyl C atoms at the equatorial positions.

Related literature

For the crystal structures of terpyridine dichlorido­zinc(II) compounds, see: Corbridge & Cox (1956 ▶); Einstein & Penfold (1966 ▶); Vlasse et al. (1983 ▶). For examples of other substituted terpyridine zinc(II) compounds, see: Harrison et al. (1986 ▶); Hou et al. (2004 ▶). The structure of a bipyridine dimethyl­zinc(II) compound was reported by Wissing et al. (1994 ▶).

Experimental

Crystal data

• [Zn(CH₃)₂(C₁₅H₁₁N₃)]

• M _r = 328.71

• Monoclinic,

• a = 17.4250 (11) Å

• b = 9.1083 (6) Å

• c = 11.7595 (14) Å

• β = 127.193 (1)°

• V = 1486.8 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 1.65 mm⁻¹

• T = 125 K

• 0.23 × 0.13 × 0.06 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.703, T _max = 0.908

• 9483 measured reflections

• 1837 independent reflections

• 1710 reflections with I > 2σ(I)

• R _int = 0.025

Refinement

• R[F ² > 2σ(F ²)] = 0.022

• wR(F ²) = 0.061

• S = 1.09

• 1837 reflections

• 98 parameters

• H-atom parameters constrained

• Δρ_max = 0.41 e Å⁻³

• Δρ_min = −0.27 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; 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.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Zn—C1	2.0282 (15)
Zn—N1	2.3381 (12)
Zn—N2	2.2603 (16)

supplementary crystallographic information

Comment

The chelating ligand 2,2':6',2''-terpyridine coordinates to a variety of first-row transition metal Lewis acids. Specifically, it can coordinate to disubstituted zinc compounds, allowing for the formation of trigonal bipyramidal zinc(II) complexes (Harrison et al., 1986). The structure of terpyridine dichlorozinc(II) has been reported a number of times with different results (Corbridge & Cox, 1956; Einstein & Penfold, 1966; Vlasse et al., 1983). In addition to substituents on the zinc(II) center, substituents on the terpyridine are also known (Hou et al., 2004). The structure presented here is the first known structure in a class of terpyridine zinc(II) compounds with two alkyl groups bound directly to the metal center.

The title compound (Fig. 1) was obtained by the reaction of dimethylzinc with 2,2':6',2''-terpyridine. It exhibits a distorted trigonal bipyramidal geometry about the metal center and has the two terminal N atoms in the axial positions, with a bond length of 2.3381 (12) Å (Table 1). The central N atom, coordinated to the zinc via the equatorial position, has a slightly smaller bond length, 2.2603 (16) Å, due to the size of the ligand, which is not able to wrap around the metal 180°. The N1—Zn—N1ⁱ bond angle is 140.52 (6)° [symmetry code: (i) -x, y, 1/2-z], illustrating the degree to which the compound is distorted from a perfectly trigonal bipyramid. The Zn—C bond length is 2.0282 (15) Å, and the C1—Zn—C1ⁱ bond angle is 133.21 (9)°: slightly greater than the expected 120° between equatorial atoms. Interestingly, the Zn—N bond lengths shown here are about 0.2 Å longer than those reported for similar terpyridine zinc(II) complexes, while the Zn—C length is expectedly shorter than the Zn—Cl and Zn—S lengths (Harrison et al., 1986; Hou et al., 2004; Vlasse et al., 1983). However, the Zn—C bond length is similar to that reported for a bipyridine dimethylzinc(II) complex, characterized by Wessing et al. (1994). The terpyridyl N1—Zn—N1ⁱ and N1—Zn—N2 bond angles are in agreement with those reported in the literature (Harrison et al., 1986; Hou et al., 2004; Vlasse et al., 1983).

Experimental

Under a nitrogen atmosphere, dimethylzinc (2 M in toluene, 1.07 ml, 2.14 mmol) was added to a stirring solution of terpyridine (0.511 g, 2.19 mmol) in toluene (3.5 ml). The resulting orange precipitate, which is extremely sensitive to hydrolysis, was filtered and dried in vacuo (yield 65%, 0.46 g). Crystallization was achieved by slow evaporation of THF in a nitrogen filled glovebox, which yielded yellow plates within five days. Analysis, calculated for C₁₇H₁₇N₃Zn: C 62.11, H 5.21, N 12.78%; found: C 59.18, H 5.09, N 12.12%. ¹H NMR (300 MHz, C₆D₆): δ -0.529 (s, 6H, –CH₃).

Refinement

A suitable crystal was mounted in a nylon loop with Paratone-N cryoprotectant oil and data was collected on a Bruker APEXII CCD platform diffractometer. H atoms were included in calculated positions and were refined using a riding model, with C—H = 0.95 (aromatic) and 0.98 (methyl) Å and with U_iso(H) = 1.2(1.5 for methyl)U_eq(C).

Figures

Fig. 1.

Molecular structure of the title compound, with displacement ellipsoids shown at the 50% probability level. [Symmetry code: (i) -x, y, 1/2-z.]

Crystal data

[Zn(CH3)2(C15H11N3)]	F(000) = 680
Mr = 328.71	Dx = 1.469 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 6987 reflections
a = 17.4250 (11) Å	θ = 2.7–28.3°
b = 9.1083 (6) Å	µ = 1.65 mm−1
c = 11.7595 (14) Å	T = 125 K
β = 127.193 (1)°	Plate, yellow
V = 1486.8 (2) Å3	0.23 × 0.13 × 0.06 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	1837 independent reflections
Radiation source: fine-focus sealed tube	1710 reflections with I > 2σ(I)
graphite	Rint = 0.025
φ and ω scans	θmax = 28.3°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −23→23
Tmin = 0.703, Tmax = 0.908	k = −12→12
9483 measured reflections	l = −15→15

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.022	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.061	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.0347P)2 + 0.7204P] where P = (Fo2 + 2Fc2)/3
1837 reflections	(Δ/σ)max < 0.001
98 parameters	Δρmax = 0.41 e Å−3
0 restraints	Δρmin = −0.27 e Å−3

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

	x	y	z	Uiso*/Ueq
Zn	0.0000	0.27994 (2)	0.2500	0.02138 (9)
N1	0.09270 (8)	0.19322 (13)	0.18122 (12)	0.0217 (2)
N2	0.0000	0.03178 (17)	0.2500	0.0181 (3)
C1	0.11086 (11)	0.36835 (17)	0.43838 (16)	0.0282 (3)
H1A	0.1292	0.4625	0.4207	0.042*
H1B	0.1660	0.3013	0.4858	0.042*
H1C	0.0909	0.3840	0.4996	0.042*
C2	0.13813 (11)	0.28148 (17)	0.14866 (16)	0.0260 (3)
H2A	0.1337	0.3846	0.1557	0.031*
C3	0.19141 (11)	0.22995 (19)	0.10513 (17)	0.0291 (3)
H3A	0.2237	0.2959	0.0845	0.035*
C4	0.19631 (10)	0.0801 (2)	0.09259 (16)	0.0298 (3)
H4A	0.2317	0.0413	0.0621	0.036*
C5	0.14921 (10)	−0.01296 (17)	0.12488 (15)	0.0261 (3)
H5A	0.1513	−0.1163	0.1160	0.031*
C6	0.09862 (9)	0.04762 (15)	0.17079 (13)	0.0197 (3)
C7	0.04737 (9)	−0.04323 (15)	0.21108 (13)	0.0188 (3)
C8	0.04827 (10)	−0.19665 (15)	0.20904 (15)	0.0239 (3)
H8A	0.0814	−0.2475	0.1801	0.029*
C9	0.0000	−0.2732 (2)	0.2500	0.0260 (4)
H9A	0.0000	−0.3775	0.2500	0.031*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Zn	0.02557 (13)	0.01758 (13)	0.02424 (13)	0.000	0.01676 (11)	0.000
N1	0.0219 (5)	0.0236 (6)	0.0222 (6)	−0.0008 (4)	0.0147 (5)	−0.0004 (4)
N2	0.0182 (7)	0.0178 (7)	0.0176 (7)	0.000	0.0105 (6)	0.000
C1	0.0330 (7)	0.0234 (7)	0.0303 (7)	−0.0055 (6)	0.0202 (7)	−0.0032 (6)
C2	0.0259 (7)	0.0279 (7)	0.0261 (7)	−0.0032 (6)	0.0167 (6)	0.0009 (6)
C3	0.0230 (7)	0.0420 (9)	0.0243 (7)	−0.0018 (6)	0.0154 (6)	0.0048 (6)
C4	0.0236 (7)	0.0461 (9)	0.0247 (7)	0.0082 (6)	0.0173 (6)	0.0050 (6)
C5	0.0252 (7)	0.0299 (8)	0.0253 (7)	0.0066 (6)	0.0164 (6)	0.0020 (6)
C6	0.0172 (6)	0.0242 (7)	0.0161 (6)	0.0021 (5)	0.0093 (5)	0.0006 (5)
C7	0.0177 (6)	0.0195 (6)	0.0167 (6)	0.0016 (5)	0.0091 (5)	−0.0005 (5)
C8	0.0230 (7)	0.0208 (7)	0.0237 (7)	0.0031 (5)	0.0119 (6)	−0.0023 (5)
C9	0.0262 (10)	0.0171 (9)	0.0276 (10)	0.000	0.0126 (9)	0.000

Geometric parameters (Å, °)

Zn—C1i	2.0282 (15)	C2—H2A	0.9500
Zn—C1	2.0282 (15)	C3—C4	1.381 (2)
Zn—N1	2.3381 (12)	C3—H3A	0.9500
Zn—N2	2.2603 (16)	C4—C5	1.383 (2)
Zn—N1i	2.3382 (12)	C4—H4A	0.9500
N1—C2	1.3364 (19)	C5—C6	1.3958 (18)
N1—C6	1.3416 (18)	C5—H5A	0.9500
N2—C7i	1.3470 (15)	C6—C7	1.4893 (18)
N2—C7	1.3470 (15)	C7—C8	1.3979 (19)
C1—H1A	0.9800	C8—C9	1.3838 (18)
C1—H1B	0.9800	C8—H8A	0.9500
C1—H1C	0.9800	C9—C8i	1.3838 (18)
C2—C3	1.385 (2)	C9—H9A	0.9500
C1i—Zn—C1	133.21 (9)	N1—C2—H2A	118.4
C1i—Zn—N2	113.39 (5)	C3—C2—H2A	118.4
C1—Zn—N2	113.39 (5)	C4—C3—C2	118.22 (14)
C1i—Zn—N1	99.05 (5)	C4—C3—H3A	120.9
C1—Zn—N1	96.37 (5)	C2—C3—H3A	120.9
N2—Zn—N1	70.26 (3)	C3—C4—C5	119.41 (14)
C1i—Zn—N1i	96.37 (5)	C3—C4—H4A	120.3
C1—Zn—N1i	99.05 (5)	C5—C4—H4A	120.3
N2—Zn—N1i	70.26 (3)	C4—C5—C6	118.83 (14)
N1—Zn—N1i	140.52 (6)	C4—C5—H5A	120.6
C2—N1—C6	118.48 (12)	C6—C5—H5A	120.6
C2—N1—Zn	123.28 (10)	N1—C6—C5	121.84 (13)
C6—N1—Zn	118.22 (9)	N1—C6—C7	115.22 (11)
C7i—N2—C7	119.05 (16)	C5—C6—C7	122.93 (13)
C7i—N2—Zn	120.48 (8)	N2—C7—C8	121.89 (13)
C7—N2—Zn	120.47 (8)	N2—C7—C6	115.77 (12)
Zn—C1—H1A	109.5	C8—C7—C6	122.34 (12)
Zn—C1—H1B	109.5	C9—C8—C7	118.82 (14)
H1A—C1—H1B	109.5	C9—C8—H8A	120.6
Zn—C1—H1C	109.5	C7—C8—H8A	120.6
H1A—C1—H1C	109.5	C8—C9—C8i	119.53 (19)
H1B—C1—H1C	109.5	C8—C9—H9A	120.2
N1—C2—C3	123.19 (14)	C8i—C9—H9A	120.2
C1i—Zn—N1—C2	68.69 (12)	C2—C3—C4—C5	−0.6 (2)
C1—Zn—N1—C2	−66.99 (12)	C3—C4—C5—C6	−0.6 (2)
N2—Zn—N1—C2	−179.60 (12)	C2—N1—C6—C5	−1.1 (2)
N1i—Zn—N1—C2	−179.60 (12)	Zn—N1—C6—C5	177.37 (10)
C1i—Zn—N1—C6	−109.70 (11)	C2—N1—C6—C7	179.08 (12)
C1—Zn—N1—C6	114.62 (11)	Zn—N1—C6—C7	−2.45 (15)
N2—Zn—N1—C6	2.01 (9)	C4—C5—C6—N1	1.5 (2)
N1i—Zn—N1—C6	2.01 (9)	C4—C5—C6—C7	−178.65 (12)
C1i—Zn—N2—C7i	−89.74 (8)	C7i—N2—C7—C8	0.42 (9)
C1—Zn—N2—C7i	90.26 (8)	Zn—N2—C7—C8	−179.58 (9)
N1—Zn—N2—C7i	178.72 (7)	C7i—N2—C7—C6	−179.48 (12)
N1i—Zn—N2—C7i	−1.28 (7)	Zn—N2—C7—C6	0.52 (12)
C1i—Zn—N2—C7	90.26 (8)	N1—C6—C7—N2	1.31 (16)
C1—Zn—N2—C7	−89.74 (8)	C5—C6—C7—N2	−178.51 (11)
N1—Zn—N2—C7	−1.28 (7)	N1—C6—C7—C8	−178.59 (13)
N1i—Zn—N2—C7	178.72 (7)	C5—C6—C7—C8	1.6 (2)
C6—N1—C2—C3	−0.3 (2)	N2—C7—C8—C9	−0.83 (19)
Zn—N1—C2—C3	−178.64 (11)	C6—C7—C8—C9	179.07 (10)
N1—C2—C3—C4	1.1 (2)	C7—C8—C9—C8i	0.39 (9)

Symmetry codes: (i) −x, y, −z+1/2.