catena-Poly[[[(dimethyl­malonato-κ2 O:O′)(perchlorato-κO)copper(II)]-μ-bis­(3-pyridylmeth­yl)piperazinediium-κ2 N 1′:N 4′] perchlorate dihydrate]

Gregory A Farnum; Robert L LaDuca

doi:10.1107/S1600536808036490

. 2008 Nov 13;64(Pt 12):m1524. doi: 10.1107/S1600536808036490

catena-Poly[[[(dimethylmalonato-κ² O:O′)(perchlorato-κO)copper(II)]-μ-bis(3-pyridylmethyl)piperazinediium-κ² N ^1′:N ^4′] perchlorate dihydrate]

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

PMCID: PMC2959823 PMID: 21581141

Abstract

In the title compound, {[Cu(C₅H₆O₄)(ClO₄)(C₁₆H₂₂N₄)]ClO₄·2H₂O}_n, square-pyramidally coordinated Cu atoms with perchlorate and dimethylmalonate ligands are connected into cationic sinusoidal coordination polymer chains by doubly protonated bis(3-pyridylmethyl)piperazine (3-bpmp) ligands. The chains aggregate into pseudo-layers parallel to the (101) crystal planes by N—H⋯O hydrogen bonding. Unligated perchlorate anions and water molecules of crystallization provide additional hydrogen bonding between pseudo-layers.

Related literature

For copper carboxylate coordination polymers containing 3-bpmp, see: Johnston et al. (2008 ▶). For the synthesis of 3-bpmp, see: Pocic et al. (2005 ▶).

Experimental

Crystal data

[Cu(C₅H₆O₄)(ClO₄)(C₁₆H₂₂N₄)]ClO₄·2H₂O
M _r = 698.95
Triclinic,
a = 9.6284 (15) Å
b = 10.5140 (16) Å
c = 14.061 (2) Å
α = 86.950 (2)°
β = 82.634 (2)°
γ = 84.638 (2)°
V = 1404.3 (4) Å³
Z = 2
Mo Kα radiation
μ = 1.04 mm⁻¹
T = 173 (2) K
0.40 × 0.30 × 0.15 mm

Data collection

Bruker SMART 1K diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.680, T _max = 0.859
14378 measured reflections
6309 independent reflections
4904 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.099
S = 1.05
6309 reflections
397 parameters
8 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.57 e Å⁻³
Δρ_min = −0.44 e Å⁻³

Data collection: SMART (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: Crystal Maker (Palmer, 2007 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808036490/lh2730sup1.cif

e-64-m1524-sup1.cif^{(27.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808036490/lh2730Isup2.hkl

e-64-m1524-Isup2.hkl^{(308.8KB, 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
O1W—H1WA⋯O12	0.894 (18)	1.98 (2)	2.838 (4)	160 (4)
O1W—H1WB⋯O8ⁱ	0.875 (18)	2.35 (3)	3.053 (4)	137 (3)
O1W—H1WB⋯O2ⁱⁱ	0.875 (18)	2.46 (3)	3.120 (3)	133 (3)
O2W—H2WA⋯O7	0.929 (19)	2.14 (2)	3.044 (4)	164 (4)
O2W—H2WB⋯O1Wⁱⁱⁱ	0.941 (19)	1.95 (3)	2.807 (5)	150 (5)
N2—H2N⋯O2^iv	0.887 (17)	1.804 (18)	2.673 (3)	166 (3)
N4—H4N⋯O4^v	0.923 (17)	1.727 (17)	2.647 (3)	175 (3)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

We gratefully acknowledge the donors of the American Chemical Society Petroleum Research Fund and Michigan State University for funding this work.

supplementary crystallographic information

Comment

In comparison to coordination polymers based on the rigid rod tether 4,4'- bipyridine, extended phases based on the flexible and hydrogen-bonding capable bis(3-pyridylmethyl)piperazine (3-bpmp) ligand are much less common (Johnston et al., 2008).

The asymmetric unit of the title compound contains a divalent copper atom, two halves of two 3-bpmp molecules protonated at their piperazinyl nitrogen atoms, one dimethylmalonate dianion, one bound and one unbound perchlorate ion and two water molecules of crystallization (Figure 1). The Cu atoms are square pyramidally coordinated in a {CuN₂O₃} arrangement, with the basal plane occupied by two cis N atom donors from two crystallographically distinct 3-bpmp ligands and two cis O atom donors from a dimethylmalonate ligand in a 1,3-chelating binding mode. The apical position is filled by a ligated perchlorate anion.

The 3-bpmp ligands link the Cu atoms into sinusoidal cationic coordination polymer chains with formulation [Cu(3-bpmpH₂)(dimethylmalonate)(ClO₄)]_nⁿ⁺ (Figure 2), in which the through ligand Cu···Cu contact distance is 15.441 Å. The "wavelength" of this chain, defined by unbridged Cu···Cu contacts, is 15.991 Å. The chains are aligned parallel to the [1 0 1] crystal direction.

Neighboring chains interdigitate and aggregate into a pseudolayer (Figure 3) parallel to the (1 0 1) crystal plane by N—H···O hydrogen bonding between protonated piperazinyl N atoms and unligated dimethylmalonate O atoms. These stack into three dimensions (Figure 4) through additional hydrogen bonding patterns involving unligated perchlorate anions and water molecule dimers, and dimethylmalonate O atoms within the coordination polymer chains.

Experimental

All chemicals were obtained commercially, except for 3-bpmp which was synthesized by a literature method (Pocic et al., 2005). Copper perchlorate hexahydrate (19 mg, 0.051 mmol) and dimethylmalonic acid (7 mg, 0.05 mmol) were dissolved in 3 ml water in a glass vial. A 1 ml aliquot of a 1:1 water:ethanol solution was carefully layered onto the aqueous solution, followed by 3 ml of an ethanolic solution of 3-bpmp (27 mg, 0.10 mmol). Blue blocks of the title compound formed after 1 week.