Hexa-μ2-bromido-μ4-oxo-tetra­kis[(nicotine)copper(II)]

Zhengjing Jiang; Guodong Tang; Lude Lu

doi:10.1107/S1600536808018473

. 2008 Jun 25;64(Pt 7):m958–m959. doi: 10.1107/S1600536808018473

Hexa-μ₂-bromido-μ₄-oxo-tetrakis[(nicotine)copper(II)]

Zhengjing Jiang ^a,^b, Guodong Tang ^a,^b, Lude Lu ^b,^*

PMCID: PMC2961882 PMID: 21202807

Abstract

In the title compound, hexa-μ₂-bromido-μ₄-oxo-tetrakis{[3-(1-methyl-2-pyrrolidinyl)pyridine-κN]copper(II)}, [Cu₄Br₆O(C₁₀H₁₄N₂)₄], the four Cu atoms are tetrahedrally arranged around the O atom at the cluster center. The Cu and coordinated N atoms lie along directions which correspond to four of the eight threefold axial directions of a regular octahedron. Each Cu atom lies at the center of a trigonal bipyramid, with the O atom and the pyridine N atom of a nicotine ligand in the axial positions and three Br atoms in the equatorial positions. Average bond distances are: Cu—N = 1.979 (8), Cu—O = 1.931 (6), Cu—Br = 2.514 (14) and Cu⋯Cu = 3.154 (6) ÅÅ. The configuration of the nicotine ligands is that of the trans diastereomer. In addition, the crystal structure contains five intramolecular C—H⋯Br hydrogen bonds, which determine (or support) the orientation of the nicotine molecules relative to their three equatorial Br atoms. One of the nicotine molecules has two C—H⋯Br contacts, while the other three nicotine molecules show only one C—H⋯Br bond each. Two other intermolecular C—H⋯Br hydrogen bonds connect the complex molecules, forming ribbons which extend in the b- and c-axis directions.

Related literature

For related literature, see: Udupa & Krebs (1980 ▶); Meyer et al. (2006 ▶); Haendler (1990 ▶).

Experimental

Crystal data

[Cu₄Br₆O(C₁₀H₁₄N₂)₄]
M _r = 1398.55
Monoclinic,
a = 12.9505 (5) Å
b = 13.2850 (3) Å
c = 14.2555 (2) Å
β = 92.221 (2)°
V = 2450.78 (11) Å³
Z = 2
Mo Kα radiation
μ = 6.64 mm⁻¹
T = 123 (2) K
0.20 × 0.16 × 0.14 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.29, T _max = 0.40
22605 measured reflections
9345 independent reflections
8124 reflections with I > 2σ(I)
R _int = 0.044

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.122
S = 1.08
9345 reflections
536 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.64 e Å⁻³
Δρ_min = −0.82 e Å⁻³
Absolute structure: Flack (1983 ▶), 4309 Friedel pairs
Flack parameter: 0.058 (15)

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXL97; software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808018473/si2090sup1.cif

e-64-0m958-sup1.cif^{(32.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808018473/si2090Isup2.hkl

e-64-0m958-Isup2.hkl^{(457KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1A⋯Br3	0.95	2.60	3.292 (9)	130
C15—H15A⋯Br4	0.95	2.71	3.362 (10)	126
C21—H21A⋯Br2	0.95	2.77	3.372 (10)	122
C25—H25A⋯Br6	0.95	2.75	3.332 (9)	120
C30—H30C⋯Br6ⁱ	0.98	2.92	3.844 (10)	158
C35—H35A⋯Br5	0.95	2.68	3.259 (10)	120
C39—H39B⋯Br5ⁱⁱ	0.99	2.88	3.764 (11)	150

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (No. 50572039) and the Natural Science Foundation of Jiangsu Province (BK2006199).

supplementary crystallographic information

Comment

Numerous clusters of nicotine [3-(1-methyl-2- pyrrolidinyl)pyridine] were reported to form molecular complexes with metals. But the crystal structures of the clusters containing both nicotine ligands and bromine atoms have not been reported so far. In order to explore the chemistry of nicotine clusters extensively, we synthesized the title cluster.

As illustrated in Fig. 1, the title compound has an O atom at the center of a tetrahedron of Cu atoms. The same O atom also lies at the center of a slightly distorted octahedron of Br atoms. This octahedron is in turn surrounded tetrahedrally by the four pyridine N atoms of the nicotine ligands, in parallel orientation with the Cu tetrahedron. The Cu atoms are bridged by the six Br atoms. The net effect is to place each Cu atom at the center of a slightly distorted trigonal bipyramid; the four bipyramids have six edges in common. The central O atom and the pyridine N atoms are in the axial positions, while the bridging Br atoms are in the equatorial positions. In addition, the absolut configurations of C6, C16, C26, and C36 can be given as S* (the * denotes unknown absolute configuration, but for the chosen coordinates the form appears to be S). The structure also contains five intramolecular and two intermolecular C—H···Br hydrogen bonds (Table 1). The intramolecular hydrogen bonds determine (or support) the orientation of the nicotine molecules relative to their equatorial three Br atoms. One of the nicotine molecules has two C—H···Br contacts: C21—H21A···Br2 and C25—H25A···Br6, the other three nicotine molecules show only one H bond. Two other intermolecular hydrogen bonds, C30—H30C···Br6 and C39—H39B···Br5, connect the complexes to form ribbons which extend in the b and c direction.

Examples of closely related compounds containing nicotine ligands include a mercury(II) chain polymer (Udupa & Krebs, 1980), a helical silver(I) coordination polymer (Meyer et al., 2006) and a chloride-nicotine copper(II) complex (Haendler, 1990).

Experimental

CuBr (1 mmol) was added to a solution of 4-cyanopyridine(1 mmol) in dmf (5 ml). The resulting mixture was stirred for about 10 min after which an orange precipitate formed. Nicotine (1 ml) was then added dropwise to the reaction mixture and stirring was continued, during which time the precipitate was dissolved, giving an orange solution.This solution then changed its colour to dark green with 30 min further stirring. The resulting solution was filtered and the dark green filtrate was transfered into a test tube and carefully laid on the surface of the filtrate with i-PrOH (10 ml). Dark-brown block crystals were obtained after 30 days. Yield: 0.158 g, 68% (based on CuBr used). Analysis: Found: C 34.52, H 3.90, N 7.90%; Calculated for C₄₀H₅₆Br₆Cu₄N₈O: C 34.35, H 4.04, N 8.01%.