Bis(perchlorato-κO)tetra­kis[1-(2-pyridyl)-4-(4-pyridylmethyl-κN)piperazine]cadmium(II)

Gregory A Farnum; Robert L LaDuca

doi:10.1107/S1600536809004437

. 2009 Feb 13;65(Pt 3):m274. doi: 10.1107/S1600536809004437

Bis(perchlorato-κO)tetrakis[1-(2-pyridyl)-4-(4-pyridylmethyl-κN)piperazine]cadmium(II)

Gregory A Farnum ^a, Robert L LaDuca ^a,^*

PMCID: PMC2968463 PMID: 21582062

Abstract

In the title compound, [Cd(ClO₄)₂(C₁₅H₁₈N₄)₄], the Cd^II ion is coordinated in a slightly distorted octahedral environment by two trans monodentate perchlorate ligands and four 1-(2-pyridyl)-4-(4-pyridylmethyl)piperazine (pmpp) ligands. In the crystal structure, molecules are organized into layers parallel to the ab plane by C—H⋯O interactions. Similar interactions promote the stacking of these layers into the three-dimensional crystal structure.

Related literature

For a silver nitrate supramolecular complex and the synthesis of pmpp, see: Farnum et al. (2009 ▶).

Experimental

Crystal data

[Cd(ClO₄)₂(C₁₅H₁₈N₄)₄]
M _r = 1328.64
Monoclinic,
a = 34.958 (4) Å
b = 9.1736 (11) Å
c = 24.153 (3) Å
β = 126.8740 (10)°
V = 6196.4 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.51 mm⁻¹
T = 173 K
0.20 × 0.16 × 0.12 mm

Data collection

Bruker SMART 1K diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2007 ▶) T _min = 0.875, T _max = 0.941
34115 measured reflections
13967 independent reflections
11273 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.084
S = 0.98
13967 reflections
784 parameters
2 restraints
H-atom parameters constrained
Δρ_max = 0.70 e Å⁻³
Δρ_min = −0.41 e Å⁻³
Absolute structure: Flack (1983 ▶), with 6755 Friedel pairs
Flack parameter: −0.041 (13)

Data collection: SMART (Bruker, 2006 ▶); cell refinement: SAINT-Plus (Bruker, 2006 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalMaker (Palmer, 2007 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809004437/lh2771sup1.cif

e-65-0m274-sup1.cif^{(46.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809004437/lh2771Isup2.hkl

e-65-0m274-Isup2.hkl^{(682.7KB, 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
C29—H29⋯O1ⁱ	0.95	2.54	3.406 (6)	152
C54—H54A⋯O7ⁱⁱ	0.99	2.57	3.348 (5)	135

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

Acknowledgments

The authors gratefully acknowledge the donors of the American Chemical Society Petroleum Research Fund for funding this work.

supplementary crystallographic information

Comment

In an attempt to prepare a cadmium perchlorate coordination polymer containing pmpp (Farnum et al., 2009), colourless blocks of the title compound were obtained. The asymmetric unit contains a single molecule, [Cd(pmpp)₄(ClO₄)₂], wherein an octahedrally coordinated Cd^II ion is bound by two trans monodentate perchlorato ligands and four pmpp ligands, bound via N atoms within their 4-pyridyl termini (Fig. 1). The title compound crystallizes in the noncentrosymmetric monoclinic space group Cc without appreciable racemic twinning, as evidenced by a Flack parameter (Flack, 1983) of -0.043 (13).

Individual [Cd(pmpp)₄(ClO₄)₂] molecules aggregate through C—H···O interactions, constructing pseudo layers coincident with the ab crystal planes (Fig. 2). In turn these layers stack in an AB pattern along the c crystal direction by a different C—H···O pathway (Fig. 3).

Experimental

All chemicals were obtained commercially. Cadmium perchlorate hexahydrate (20 mg, 0.064 mmol) was dissolved in 1.5 ml water in a glass vial at 298 K. A 0.75 ml aliquot of a 1:1 water–ethanol mixture was carefully layered onto the aqueous solution, followed by 1.5 ml of an ethanolic solution of pmpp (32.5 mg, 0.128 mmol). Colourless blocks of the title compound formed after 2 weeks.