trans-Bis[(1-ammonio­pentane-1,1-di­yl)diphospho­nato-κ2 O,O′]diaqua­copper(II)

Natalia V Tsaryk; Anatolij V Dudko; Alexandra N Kozachkova; Vladimir V Bon; Vasily I Pekhnyo

doi:10.1107/S1600536810045216

. 2010 Nov 10;66(Pt 12):m1533–m1534. doi: 10.1107/S1600536810045216

trans-Bis[(1-ammoniopentane-1,1-diyl)diphosphonato-κ² O,O′]diaquacopper(II)

Natalia V Tsaryk ^a,^*, Anatolij V Dudko ^a, Alexandra N Kozachkova ^a, Vladimir V Bon ^a, Vasily I Pekhnyo ^a

PMCID: PMC3011560 PMID: 21589232

Abstract

In the title compound, [Cu(C₅H₁₄NO₆P₂)₂(H₂O)₂], the Cu^II atom occupies a special position on an inversion centre. It exhibits a distorted octahedral coordination environment consisting of two O,O′-bidentate (1-ammoniopentane-1,1-diyl)diphosphonate anions in the equatorial plane and two trans water molecules located in axial positions. The ligand molecules are coordinated to the Cu^II atom in their zwitterionic form via two O atoms from different phosphonate groups, creating two six–membered chelate rings with a screw-boat conformation. The CuO₆ coordination polyhedron is strongly elongated in the axial direction with 0.6 Å longer bonds than those in the equatorial plane. Intramolecular N—H⋯O hydrogen bonding helps to stabilize the molecular configuration. The presence of supramolecular —PO(OH)⋯O(OH)P— units parallel to (100) and other O—H⋯O and N—H⋯O hydrogen bonds establish the three-dimensional set-up.

Related literature

For general background to organic diphosphonic acids and their metal complexes, see: Eberhardt et al. (2005 ▶); Matczak-Jon & Videnova-Adrabinska (2005 ▶). For related structures, see: Sergienko et al. (1997 ▶, 1999 ▶).

Experimental

Crystal data

[Cu(C₅H₁₄NO₆P₂)₂(H₂O)₂]
M _r = 591.80
Triclinic,
a = 5.5629 (1) Å
b = 10.0236 (2) Å
c = 10.5237 (2) Å
α = 69.315 (1)°
β = 86.666 (1)°
γ = 88.398 (1)°
V = 548.03 (2) Å³
Z = 1
Mo Kα radiation
μ = 1.36 mm⁻¹
T = 173 K
0.35 × 0.15 × 0.08 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.648, T _max = 0.899
5322 measured reflections
2277 independent reflections
2104 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.023
wR(F ²) = 0.064
S = 1.07
2277 reflections
168 parameters
4 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.36 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg & Putz, 2010 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810045216/wm2420sup1.cif

e-66-m1533-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810045216/wm2420Isup2.hkl

e-66-m1533-Isup2.hkl^{(111.9KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Cu1—O4	1.9381 (12)
Cu1—O1	1.9524 (12)
Cu1—O7	2.5666 (15)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H11N⋯O3ⁱ	0.91 (2)	1.98 (3)	2.849 (2)	158 (2)
N1—H12N⋯O7ⁱⁱ	0.88 (2)	2.08 (3)	2.945 (2)	167 (2)
N1—H13N⋯O5ⁱ	0.89 (3)	1.99 (3)	2.849 (2)	162 (2)
O2—H2O⋯O3ⁱⁱⁱ	0.79 (2)	1.79 (2)	2.5741 (18)	178 (3)
O6—H6O⋯O5^iv	0.79 (2)	1.80 (2)	2.5848 (18)	176 (3)
O7—H71O⋯O4^v	0.79 (2)	2.04 (2)	2.8071 (19)	165 (3)
O7—H72O⋯O2ⁱⁱ	0.79 (2)	2.56 (3)	3.010 (2)	118 (3)

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

Acknowledgments

The authors thank the Ukraininan National Academy of Sciences for financial support of this work.

supplementary crystallographic information

Comment

The investigation of organic diphosphonic acids and their metal complexes attracts constant interest of chemists because of their potential applications as drugs preventing calcification and inhibiting bone resorption (Matczak-Jon & Videnova-Adrabinska, 2005). Some transition metal diphosphonates can improve fixation of cementless metal implants by enhancing the extent of osteointegration (Eberhardt et al., 2005). Therefore, a detailed structural investigation of diphosphonates may help to better understand their structure-property correlations.

Several structures of copper diphosphonates have been published earlier (Sergienko et al., 1997, 1999). The present paper reports the structure of the first complex compound with (1-ammoniopentane-1,1-diyl)diphosphonic acid.

The asymmetric unit of title compound contains one half of the molecule. The Cu^II atom occupies a special position on a crystallographic inversion centre, which generates another half of the molecule (Fig. 1). The central Cu^II atom exhibits a distorted octahedral coordination geometry consisting of two O,O'-bidentantely coordinating ligand molecules in the equatorial plane and two trans water molecules, located in the axial positions. The ligand molecules are coordinated to Cu^II in their zwitterionic form via two O atoms from different phosphonate groups creating two six-membered chelate metalla rings with a screw-boat conformation. The CuO₆ coordination polyhedron is strongly elongated in the axial direction: The Cu1—O7 bond is ~ 0.6 Å longer than the Cu1—O1 and Cu1—O4 bonds (Table 1), which is characteristic for Jahn-Teller distorted Cu^II complexes with an octahedral coordination (Sergienko et al., 1997). The values of the equatorial O—Cu—O angles are in the range of 80.05 (5)–99.95 (5)°, indicating a significiant deviation from the ideal values. This can be explained by the presence of a strong intramolecular hydrogen bond N1—H12···O7 (Fig. 1, Table 2), which partially influences the configuration of the molecule. The crystal structure of title compound contains supramolecular units —PO(OH)···O(OH)P— parallel to (100) that, together with strong O—H···O and N—H···O hydrogen bonds, create a three-dimensional structure (Fig. 2, Table 2).

Experimental

Light blue crystals of the title compound were obtained from the mixture of CuSO₄^.5H₂O (0.2 mmol, 0.04995 g) and 1-aminopentane-1,1-diyldiphosphonic acid (0.4 mmol, 0.09885 g) in 5 ml of H₂O, adjusted to pH ~ 4 with 0.25M NaOH. The combined solution was stored in a dark place for slow evaporation. After 20 days of staying, suitable crystals for X-ray data collection were obtained.