[(Triethyl­ene­tetra­mine)copper(II)]-μ-cyanido-κ2N:C-[bis(cyanido-κC)copper(I)]

Corfield, P.W.R.; Grillo, S.A.; Umstott, N.S.

doi:10.1107/S1600536812047745

Volume 68
Part 12
Pages m1532-m1533
December 2012

Received 3 November 2012
Accepted 20 November 2012
Online 24 November 2012

Key indicators
Single-crystal X-ray study
T = 295 K
Mean (C-C) = 0.008 Å
R = 0.039
wR = 0.120
Data-to-parameter ratio = 12.6
Details

[(Triethylenetetramine)copper(II)]--cyanido-²N:C-[bis(cyanido-C)copper(I)]

Peter W. R. Corfield,^a ^* Scott A. Grillo ^b and Nancy S. Umstott ^b ⁺

^aDepartment of Chemistry, Fordham University, 441 East Fordham Road, Bronx, NY 10458, USA, and ^bThe King's College, Briarcliff Manor, NY 10510, USA
Correspondence e-mail: pcorfield@fordham.edu

The title compound, [Cu₂(CN)₃(C₆H₁₈N₄)] or [Cu(trien)(CN)Cu(CN)₂], where trien is triethylenetetramine, is a mixed-valence complex crystallizing as discrete molecules, with Cu^I and Cu^II ions linked by a bridging cyanide group. The Cu^II ion is in a square-pyramidal coordination environment, with the N atoms of the tetradentate trien ligand occupying the basal positions and Cu-N bond lengths in the range 2.028 (4)-2.047 (4) Å. An N-bonded cyanide group is in the apical position, with a slightly longer Cu-N bond length of 2.127 (4) Å. The Cu^I ion exhibits a trigonal-planar coordination geometry, bonded to the C atoms of the bridging cyanide group and two terminal cyanide groups with Cu-C bond lengths in the range 1.925 (4)-1.948 (5) Å. In the crystal, hydrogen bonding involving the tertiary N-H groups of the trien ligand and N atoms of symmetry-related terminal cyanide groups links molecules into a ribbon extending in the b-axis direction.

Related literature

For mixed-valence copper cyanide complexes crystallizing as one- two- and three-dimensional self-assembled polymeric networks involving cyanide groups bridging copper atoms, see: Williams et al. (1972); Colacio et al. (2002); Kim et al. (2005). For discrete molecules containing terminal cyanide groups which are not involved in any covalent polymeric linkages, see: Yuge et al. (1998); Pickardt et al. (1999); Pretsch et al. (2005). For the structure of a related one-dimensional polymer, see: Corfield & Yang (2012). For cyanide analysis, see: Cooper & Plane (1966).

Experimental

Crystal data

[Cu₂(CN)₃(C₆H₁₈N₄)]
M_r = 351.38
Triclinic, $[P \overline 1]$
a = 7.363 (3) Å
b = 8.741 (6) Å
c = 11.492 (6) Å
= 77.84 (3)°
= 73.78 (3)°
= 83.18 (3)°
V = 692.8 (7) Å³
Z = 2
Cu K radiation
= 3.75 mm^-1
T = 295 K
0.7 × 0.2 × 0.1 mm

Data collection

GE 1/4 circle manual diffractometer
Absorption correction: integration (Busing & Levy, 1957) T_min = 0.515, T_max = 0.746
2734 measured reflections
2060 independent reflections
1975 reflections with I > 2(I)
R_int = 0.042
_max = 60.0°
3 standard reflections every 22 reflections intensity decay: 0.2 (2)%

Refinement

R[F² > 2(F²)] = 0.039
wR(F²) = 0.120
S = 1.16
2060 reflections
163 parameters
H-atom parameters constrained
_max = 0.51 e Å^-3
_min = -0.56 e Å^-3

Table 1
Selected bond lengths (Å)

Cu1-C1	1.947 (4)
Cu1-C2	1.925 (4)
Cu1-C3	1.948 (5)
Cu2-N1	2.127 (4)
Cu2-N4	2.045 (4)
Cu2-N7	2.034 (4)
Cu2-N10	2.047 (4)
Cu2-N13	2.028 (4)

Table 2
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
N7-H7N2ⁱ	0.91	2.14	2.984 (6)	154
N10-H10N3ⁱⁱ	0.91	2.28	3.178 (6)	171
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x+1, -y, -z+1.

Data collection: locally modified program (Corfield, 1984); cell refinements and data reduction followed procedures described by Corfield et al. (1973); data were averaged with SORTAV (Blessing, 1989); program(s) used to solve structure: locally modified program (Corfield, 1984); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and XABS2 (Parkin et al., 1995); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: SHELXL97.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LH5552 ).

Acknowledgements

We thank Linda Kuzcko, Ruth Josenhans, John Oskam, and Mary Lou Eckels for their assistance in this work. We also acknowledge gratefully an Atlantic Richfield Foundation grant from the Research Corporation, and funding from the Alumni Association of The King's College, where the experimental work was carried out.

References

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