Di-μ-methacrylato-κ4 O:O′-bis­[aqua­bis(1,10-phenanthroline-κ2 N,N′)copper(II)] dinitrate dihydrate

M T H Tarafder; M Y Reza; K A Crouse; Suchada Chantrapromma; Hoong-Kun Fun

doi:10.1107/S1600536808016218

. 2008 Jun 7;64(Pt 7):m872–m873. doi: 10.1107/S1600536808016218

Di-μ-methacrylato-κ⁴ O:O′-bis[aquabis(1,10-phenanthroline-κ² N,N′)copper(II)] dinitrate dihydrate

M T H Tarafder ^a,^*, M Y Reza ^a, K A Crouse ^b, Suchada Chantrapromma ^c,^‡, Hoong-Kun Fun ^d,^§

PMCID: PMC2961707 PMID: 21202745

Abstract

The title complex, [Cu₂(C₄H₅O₂)₂(C₁₂H₈N₂)₂(H₂O)₂](NO₃)₂·2H₂O, contains a dimeric [Cu₂(C₄H₅O₂)₂(C₁₂H₈N₂)₂(H₂O)₂]²⁺ dication with two five-coordinated Cu^II ions linked by two methacrylate ions in a syn–syn bridging arrangement. The dication possesses pseudo-twofold rotational symmetry. The pentacoordination of each Cu^II ion has a distorted square-pyramidal geometry, with two N donors from a phenanthroline ligand and two carboxylate O atoms occupying basal sites and the apical position being occupied by a water molecule. In the crystal packing, molecules are linked to form a three-dimensional framework by O—H⋯O and C—H⋯O hydrogen bonds and π–π interactions [centroid–centroid distances of 3.6039 (15), 3.5301 (15), 3.6015 (15), 3.6496 (15) and 3.6858 (15) Å].

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For structures of related copper(II) complexes, see: Chen et al. (2008 ▶); Perlepes et al. (1995 ▶). For related literature, see: Besecke et al. (1989 ▶); Blackburn et al. (1995 ▶); Chen et al. (2007 ▶); Dang (1994 ▶); Houser et al. (1996 ▶); Matsushima et al. (1995 ▶); Reza et al. (1998 ▶, 1999 ▶, 2003 ▶); Tokii et al. (1989 ▶, 1990 ▶, 1992 ▶, 1995 ▶); Schubert (1996 ▶); Schubert et al. (1992 ▶, 1995 ▶).

Experimental

Crystal data

[Cu₂(C₄H₅O₂)₂(C₁₂H₈N₂)₂(H₂O)₂](NO₃)₂·2H₂O
M _r = 853.75
Monoclinic,
a = 13.6146 (2) Å
b = 15.7322 (2) Å
c = 16.4463 (2) Å
β = 102.1306 (8)°
V = 3443.94 (8) Å³
Z = 4
Mo Kα radiation
μ = 1.31 mm⁻¹
T = 100.0 (1) K
0.27 × 0.24 × 0.16 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.716, T _max = 0.822
43546 measured reflections
10036 independent reflections
6885 reflections with I > 2σ(I)
R _int = 0.069

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.113
S = 1.04
10036 reflections
489 parameters
H-atom parameters constrained
Δρ_max = 0.68 e Å⁻³
Δρ_min = −0.78 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808016218/ci2604sup1.cif

e-64-0m872-sup1.cif^{(32.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808016218/ci2604Isup2.hkl

e-64-0m872-Isup2.hkl^{(490.8KB, 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—H1W1⋯O6ⁱ	0.85	2.42	3.115 (3)	140
O1W—H1W1⋯O8ⁱ	0.85	2.32	2.882 (3)	124
O2W—H1W2⋯O5ⁱⁱ	0.85	2.03	2.761 (3)	144
O3W—H1W3⋯O5	0.86	1.97	2.811 (3)	163
O4W—H1W4⋯O10ⁱⁱⁱ	0.93	2.02	2.807 (3)	142
O1W—H2W1⋯O3Wⁱ	0.85	2.19	2.791 (3)	127
O3W—H2W3⋯O9ⁱⁱⁱ	0.91	2.00	2.862 (3)	157
O4W—H2W4⋯O7ⁱⁱⁱ	0.84	2.29	2.860 (3)	125
C1—H1A⋯O4	0.93	2.56	3.035 (3)	112
C1—H1A⋯O10^iv	0.93	2.53	3.247 (3)	134
C3—H3A⋯O9^v	0.93	2.37	3.186 (4)	146
C14—H14A⋯O4W^vi	0.93	2.52	3.364 (4)	151
C15—H15A⋯O2Wⁱⁱ	0.93	2.49	3.357 (3)	155
C21—H21A⋯O3^v	0.93	2.39	3.318 (4)	179
C28—H28B⋯O3	0.93	2.42	2.747 (4)	100
C32—H32B⋯O1	0.93	2.42	2.737 (4)	100
C32—H32B⋯O8ⁱ	0.93	2.43	3.345 (3)	168

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

Acknowledgments

MTHT and MYR thank Rajshahi University for the provision of laboratory facilities. KAC thanks the Universiti Putra Malaysia for financial assistance. SC thanks Prince of Songkla University for generous support. The authors also thank the Universiti Sains Malaysia for University Golden Goose Grant No. 1001/PFIZIK/811012.

supplementary crystallographic information

Comment

There is considerable interest in bioinorganic chemistry of metal carboxylates as these are formally analogous to organic esters (Dang, 1994; Reza et al., 2003). In this type of complex, the reactivity of the carboxylates towards the nucleophiles is enhanced (Houser et al., 1996; Blackburn et al., 1995; Reza et al., 1998; 1999; Tokii et al., 1989). Since transition metal complexes of methacrylic acid are also polymeric (Schubert, 1996; Schubert et al., 1992, 1995), chemists are attracted to study the application of these types of materials, particularly as catalysts. The Cu^II ions coordinate with a variety of carboxylates (Besecke et al., 1989; Matsushima et al., 1995). Such related coordinations have appeared in a series of binuclear Cu^II complexes with 1,3-bis(hydroxyphenyl)-2-imidazolidinethione, [Cu(RCOO)(HL¹)]₂ (R = CH₃, C₆H₅),(HL¹= 1-hydroxymethyl-3-methyl-2-imidazolidinethione), [Cu(RCOO)(L²)]₂ (R = CH₃, 2-CH₃C₆H₄, and 4-CH₃C₆H₄) (imidazolidinethione being the second substituent of the aryl ring) (Tokii et al., 1995), bis(µ-carboxylato-O,O')-diaquobis (1,10-pherathroline) dicopper(II) dinitrate tetrahydrates [Cu(RCOO)(phen)(H₂O)]₂(NO₃)₂. 4H₂O [R = H, CH₃ and (CH₃)₃C] (Tokii et al., 1990; 1992). Matsushima et al. (1995) have reported some triply bridged dinuclear carboxylato copper (II) complexes, [Cu₂(Ph₂CHCOO)₃(L)₂]BF4 [L = 2.2'-bipyridine and 1,10-phenanthroline]. From these related coordinations (Perlepes et al., 1995), we found there is no report on conjugated double-bond systems containing a monobasic acid (e.g. methacrylic acid) with syn–syn bridging modes of binuclear Cu(II) and this has prompted us to attempt to prepare a binuclear Cu(II) complex with phenanthroline (phen) and methacrylic acid. Methacrylic acid and phenanthroline were used to gain some insight into the flexiblity of these complexes and also the effect of these auxiliary ligands on stacking. We report herein the first example of a binuclear Cu^II complex of this type, [Cu(C₃H₅COO)(phen)(H₂O)]₂(NO₃)₂.2H₂O, along with its crystal structure.

The asymmetric unit of the title compound consists of a dinuclear [Cu(C₃H₅COO)(phen)(H₂O)]₂²⁺ cation, two NO₃^- anions and two H₂O molecules (Fig. 1). The coordination environment of each Cu^II ion is CuN₂O₃ in which the basal positions are formed by two N atoms from a bidentate phenanthroline ligand [Cu1—N1 = 2.014 (2) Å, Cu1—N2 = 2.018 (2) Å and Cu2—N3 = 2.008 (2) Å, Cu2—N4 = 2.019 (2) Å] and two O atoms of two bridging methacrylato ligands [Cu1—O1 = 1.9641 (19) Å, Cu1—O4 = 1.9446 (18) Å and Cu2—O2 = 1.9440 (19) Å, Cu2—O3 = 1.956 (2) Å]. The two carboxylate groups are in the bidentate syn–syn bridging mode. The apical position of each Cu^II is occupied by an O atom of a water molecule [Cu1—O1W = 2.1525 (19) Å and Cu2—O2W = 2.1538 (18) Å]. These axial bonds are longer than the bond lengths in the basal positons. Coordination of the N₂ chelate phenanthroline ligand to the Cu^II ion results in the formation of two planar five-membered rings Cu1/N1/N2/C11/C12 (with a maximum deviation of -0.019 (1) Å for atom Cu1) and Cu2/N3/N4/C23/C24 (with a maximum deviation of 0.014 (3) Å for atom C23). The dihedral angle between these two five-membered rings is 5.48 (10)°. The Cu1···Cu2 distance is 3.106 (1) Å. The orientation of the two bridging methacrylato ligands can be indicated by the dihedral angle between the mean planes through Cu1/O3/O4/C25 and Cu2/O1/O2/C29 of 71.74 (13)°. The electron delocalizations in the two carboxylate fragments are complete as can be indicated by the almost equal C—O bond lengths [C25—O3 = 1.263 (3) Å, C25—O4 = 1.261 (3) Å and C29—O1 = 1.259 (3) Å, C29—O2 = 1.266 (3) Å]. All bond lengths are in agreement with other related structures (Chen et al., 2008; Perlepes et al., 1995) and are in normal ranges (Allen et al., 1987).

The two phen ligands of the dinuclear complex are stacked with their centroids separated by 3.625 (1) Å indicating significant π–π interactions. The various centroid–centroid separations involving the two phen ligands are: Cg1···Cg3 = 3.6039 (15)Å, Cg1···Cg6 = 3.5301 (15)Å, Cg2···Cg4 = 3.6015 (15)Å, Cg4···Cg5 = 3.6496 (15)Å and Cg5···Cg6 = 3.6858 (15)Å (Cg1, Cg2, Cg3, Cg4, Cg5 and Cg6 are the centroids of the N1/C1–C4/C12, N2/C7–C11, N3/C13–C16/C24, N4/C19–C23, C4–C7/C11/C12 and C16–C19/C23/C24 rings, respectively).

O—H···O hydrogen bonds between water molecules and the nitrate ions play an important role in stabilizing the crystal structure (Table 1). These hydrogen bonds link the complex molecules, water molecules and nitrate groups into a two-dimensional network parallel to the (010) plane. The two-dimensional network is further strengthened by π–π interactions between two symmetry related C4–C7/C11/C12 rings at (x, y, z) and (1-x, 2-y, 1-z), with their centroids separated by 3.5381 (15) Å. The adjacent two-dimensional network are cross-linked along the b axis via weak C—H···O interactions.

Experimental

The title compound was synthesized by adding a mixture of methacrylic acid (10 mmol) and 1,10-phenanthroline (10 mmol) in water (60 ml) with triethylamine (10 mmol) to aqueous Cu(NO₃)₂ (2.42 g, 10 mmol) in water (20 ml) while stirring. The stirring was continued for another half an hour. Precipitates initially formed were filtered and the filtrate was concentrated to one-third of its original volume (25 ml). Deep blue single crystals of the title compound which appeared after a week were collected, washed with water and dried in air at room temperature (m.p. 494 K).