research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 72| Part 2| February 2016| Pages 147-150

Crystal structure of μ-oxalodi­hydroxamato-bis­­[(2,2′-bipyrid­yl)(di­methyl sulfoxide-κO)copper(II)] bis­­(perchlorate)

CROSSMARK_Color_square_no_text.svg

aO.O. Bohomolets National Medical University, Department of General Chemistry, Pr. Pobedy, 34, Kiev, 03055 , Ukraine, bTaras Shevchenko National University of Kiev, Department of Chemistry, Volodymyrska str. 62, Kiev, 01601 , Ukraine, and cUniversity of Joensuu, Department of Chemistry, PO Box 111, FI-80101 Joensuu, Finland
*Correspondence e-mail: annpavlis@ukr.net

Edited by J. Simpson, University of Otago, New Zealand (Received 1 December 2015; accepted 2 January 2016; online 13 January 2016)

The centrosymmetric binuclear complex, [Cu2(C2H2N2O4)(C10H8N2)2(C2H6OS)2](ClO4)2, contains two copper(II) ions, connected through an N-deprotonated oxalodi­hydroxamic acid dianion, two terminal 2,2′-bi­pyridine ligands, and two apically coordinating dimethylsulfoxide mol­ecules. Two non-coordinating perchlorate anions assure electrical neutrality. The copper(II) ions in the complex dication [Cu2(C10H8N2)2(μ-C2H2N2O4)(C2H6SO)2]2+ are in an O2N3 square-pyramidal donor environment, the Cu–Cu separation being 5.2949 (4) Å. Two hydroxamate groups in the deprotonated oxalodi­hydroxamic acid are located trans to one each other. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds link the complex cations to the perchlorate anions. Further C—H⋯O hydrogen bonds combine with ππ contacts with a centroid-to-centroid separation of 3.6371 (12) Å to stack the mol­ecules along the a-axis direction.

1. Chemical context

Syntheses of complexes based on functionalized hydroxamic acids are of particular inter­est due to their non-trivial magnetic (Pavlishchuk et al., 2014[Pavlishchuk, A. V., Kolotilov, S. V., Zeller, M., Thompson, L. K. & Addison, A. W. (2014). Inorg. Chem. 53, 1320-1330.]) and luminescence (Jankolovits et al., 2011[Jankolovits, J., Andolina, C. M., Kampf, J. W., Raymond, K. N. & Pecoraro, V. L. (2011). Angew. Chem. Int. Ed. 50, 9660-9664.]) properties, potential applications in bioinorganic modeling (Marmion et al., 2004[Marmion, C. J., Griffith, D. & Nolan, K. B. (2004). Eur. J. Inorg. Chem. pp. 3003-3016.]), adsorption (Pavlishchuk et al., 2010[Pavlishchuk, A. V., Kolotilov, S. V., Zeller, M., Thompson, L. K., Fritsky, I. O., Addison, A. W. & Hunter, A. D. (2010). Eur. J. Inorg. Chem. pp. 4851-4858.], 2011a[Pavlishchuk, A. V., Kolotilov, S. V., Zeller, M., Shvets, O. V., Fritsky, I. O., Lofland, S. E., Addison, A. W. & Hunter, A. D. (2011a). Eur. J. Inorg. Chem. pp. 4826-4836.];), catalysis (Mezei et al., 2007[Mezei, G., Zaleski, C. M. & Pecoraro, V. L. (2007). Chem. Rev. 107, 4933-5003.]) and the creation of recognition agents (Lim et al., 2011[Lim, C.-S., Jankolovits, J., Zhao, P., Kampf, J. W. & Pecoraro, V. L. (2011). Inorg. Chem. 50, 4832-4841.]). The majority of complexes obtained with hydroxamic acids and additional donor ligands belong to different families of metallacrown coordination compounds (Mezei et al., 2007[Mezei, G., Zaleski, C. M. & Pecoraro, V. L. (2007). Chem. Rev. 107, 4933-5003.]). Other topologies for polydentate hydroxamate-based complexes are more unusual (Gumienna-Kontecka et al., 2013[Gumienna-Kontecka, E., Golenya, I. A., Szebesczyk, A., Haukka, M., Krämer, R. & Fritsky, I. O. (2013). Inorg. Chem. 52, 7633-7644.]; Golenya et al., 2014[Golenya, I. A., Gumienna-Kontecka, E., Haukka, M., Korsun, O. M., Kalugin, O. N. & Fritsky, I. O. (2014). CrystEngComm, 16, 1904-1918.]). Here we present the structure of the binuclear complex [Cu2(C10H8N2)2(μ-C2H2N2O4)(C2H6SO)2](ClO4)2 (I)[link], obtained from oxalodi­hydroxamic acid and bi­pyridine in DMSO solution.

[Scheme 1]

2. Structural commentary

The title compound (I)[link] consists of a centrosymmetric complex di-cation [Cu2(C10H8N2)2(μ-C2H2N2O4)(C2H6SO)2]2+ with two uncoordinating perchlorate counter-anions (Fig. 1[link]). The two copper(II) cations are connected through a doubly deprotonated oxalodi­hydroxamic acid, which serves as a bridging ligand between the copper ions which are coordinated by two nitro­gen atoms from the 2,2′-bi­pyridine ligand, one carbonyl oxygen atom and the deprotonated hydroxamate nitro­gen atom from one half of the oxalodi­hydroxamato ligand and the O atom of a DMSO mol­ecule. The oxalodi­hydroxamato dianion is in a trans-form, while for metallacrown formation the cis-form is preferred. The coordination sphere of the copper(II) cation is square-pyramidal (τ = 0.21; Addison et al., 1984[Addison, A. W., Rao, T. N., Reedijk, J., van Rijn, J. & Verschoor, G. C. (1984). J. Chem. Soc. Dalton Trans. pp. 1349-1356.]) and the copper(II) ion deviates from the mean plane of the O1/N1/N2/N3 donor atoms by 0.1868 (2) Å. The separation between the copper (II) cations is 5.2949 (4) Å. The equatorial Cu—N and Cu—O distances are typical of those for copper(II) complexes with hydroxamate and oxime donor groups (Buvailo et al., 2012[Buvailo, A. I., Pavlishchuk, A. V., Penkova, L. V., Kotova, N. V. & Haukka, M. (2012). Acta Cryst. E68, m1480-m1481.]; Duda et al., 1997[Duda, A. M., Karaczyn, A., Kozłowski, H., Fritsky, I. O., Głowiak, T., Prisyazhnaya, E. V., Sliva, T. Yu. & Świątek-Kozłowska, J. (1997). J. Chem. Soc. Dalton Trans. pp. 3853-3860.]; Pavlishchuk et al., 2011b[Pavlishchuk, A. V., Kolotilov, S. V., Fritsky, I. O., Zeller, M., Addison, A. W. & Hunter, A. D. (2011b). Acta Cryst. C67, m255-m265.]; Safyanova et al., 2015[Safyanova, I. S., Golenya, I. A., Pavlenko, V. A., Gumienna-Kontecka, E., Pekhnyo, V. I., Bon, V. V. & Fritsky, I. O. (2015). Z. Anorg. Allg. Chem. 641, 2326-2332.], Table 1[link]). The elongated apical bond, Cu1—O2 (2.2516 (16) Å), compared to the Cu—O and Cu—N distances in the equatorial plane that range from 1.9848 (16) to 1.9966 (19) Å, Table 1[link], is most likely due to Jahn–Teller distortion.

Table 1
Selected geometric parameters (Å, °)

Cu1—O1 1.9848 (16) Cu1—O2 2.2516 (16)
Cu1—N2 1.985 (2) O1—C11 1.286 (3)
Cu1—N3i 1.986 (2) O5—N3 1.404 (3)
Cu1—N1 1.9966 (19)    
       
O1—Cu1—N2 90.36 (7) O1—Cu1—O2 98.04 (6)
O1—Cu1—N3i 82.73 (7) N2—Cu1—O2 97.53 (7)
N2—Cu1—N1 81.76 (8) N3i—Cu1—O2 96.15 (7)
N3i—Cu1—N1 103.13 (8) N1—Cu1—O2 90.72 (7)
Symmetry code: (i) -x+1, -y, -z+1.
[Figure 1]
Figure 1
The crystal structure of complex (I)[link], showing the atom labeling. Displacement ellipsoids are drawn at the 50% probability level.

The C—N and C—C bond lengths in the 2,2′-bi­pyridine ligands are also normal for 2-substituted pyridine derivatives (Krämer et al., 2000[Krämer, R. & Fritsky, I. O. (2000). Eur. J. Org. Chem. pp. 3505-3510.]; Strotmeyer et al., 2003[Strotmeyer, K. P., Fritsky, I. O., Ott, R., Pritzkow, H. & Krämer, R. (2003). Supramol. Chem. 15, 529-547.]; Fritsky et al., 2004[Fritsky, I. O., Świątek-Kozłowska, J., Dobosz, A., Sliva, T. Y. & Dudarenko, N. M. (2004). Inorg. Chim. Acta, 357, 3746-3752.]). The coordinating oxalo­hydroxamate dianion also has C—C, C—N, N—N bond lengths that are typical of N-deprotonated hydroxamate groups (Świątek-Kozłowska et al., 2000[Świątek-Kozłowska, J., Fritsky, I. O., Dobosz, A., Karaczyn, A., Dudarenko, N. M., Sliva, T. Yu., Gumienna-Kontecka, E. & Jerzykiewicz, L. (2000). J. Chem. Soc. Dalton Trans. pp. 4064-4068.]; Dobosz et al., 1999[Dobosz, A., Dudarenko, N. M., Fritsky, I. O., Głowiak, T., Karaczyn, A., Kozłowski, H., Sliva, T. Yu. & Świątek-Kozłowska, J. (1999). J. Chem. Soc. Dalton Trans. pp. 743-750.]).

3. Supra­molecular features

In the crystal structure, O5—H5O⋯O6 together with C12—H12A⋯O9 hydrogen bonds link the cations and associated perchlorate anions. An extensive series of other C—H⋯O contacts, Table 2[link], link the complex cations to other anions. The O2 atom of the DMSO ligand acts as a bifurcated acceptor forming C4—H4⋯O2 and C7—H7⋯O2 hydrogen bonds. These hydrogen bonds combine with ππ contacts between the N2/C6–C10 ring of the bi­pyridine and the Cu1/O1/C11/C11i/N3 ring formed by the chelating oxalodi­hydroxamate ligand with a centroid-to-centroid distance of 3.6371 (12) Å to stack the cations along the a-axis direction, Fig. 2[link].

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O5—H5O⋯O6 0.92 (5) 2.12 (5) 2.912 (3) 144 (4)
C4—H4⋯O2ii 0.95 2.42 3.359 (3) 171
C7—H7⋯O2ii 0.95 2.31 3.226 (3) 162
C3—H3⋯O7iii 0.95 2.50 3.239 (3) 134
C13—H13A⋯O7iv 0.98 2.56 3.409 (3) 145
C13—H13C⋯O8v 0.98 2.48 3.346 (3) 148
C13—H13B⋯O8vi 0.98 2.65 3.442 (3) 138
C12—H12A⋯O9 0.98 2.36 3.175 (3) 140
C8—H8⋯O9ii 0.95 2.56 3.462 (3) 159
C12—H12B⋯O9vi 0.98 2.59 3.470 (3) 150
Symmetry codes: (ii) x+1, y, z; (iii) x+1, y+1, z; (iv) -x+1, -y, -z; (v) x, y+1, z; (vi) -x+2, -y, -z.
[Figure 2]
Figure 2
The crystal packing of complex (I)[link].

4. Database survey

A search in the Cambridge Structural Database (Version 5.35, May 2014; Groom & Allen, 2014[Groom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662-671.]) shows that there are seven reports devoted to the study of crystal structures of oxalodi­hydroxamic acid and its complexes. In the reported crystal structures of oxalodi­hydroxamic acid and its salts, the compound crystallized only in the trans-form. The bond lengths in oxalodi­hydroxamic acid itself and in its ammonium and thallium salts do not differ significantly [C—C bonds are in the range 1.51 (2)–1.528 (3) Å, C=O 1.231 (3)–1.248 (3) Å, C—N 1.310 (4)–1.33 (2) Å while the N—O bond lengths vary from 1.36 (2) to 1.388 (1) Å; Lowe-Ma & Decker, 1986[Lowe-Ma, C. K. & Decker, D. L. (1986). Acta Cryst. C42, 1648-1649.]; Sameena Begum et al., 1987[Sameena Begum, A., Jain, V. K., Khetrapal, C. L. & Shivaprakash, N. C. (1987). J. Crystallogr. Spectrosc. Res. 17, 545-555.], 1988[Sameena Begum, A., Jain, V. K., Ramakumar, S. & Khetrapal, C. L. (1988). Acta Cryst. C44, 1047-1049.]; Huang et al., 1991[Huang, S.-H., Wang, R.-J. & Mak, T. C. W. (1991). J. Chem. Soc. Dalton Trans. pp. 1379-1381.]; Marsh, 1989[Marsh, R. E. (1989). Acta Cryst. C45, 347.]). Only two structures of coordination compounds with di­hydroxy­oxamidato ligands were found. Both involved anionic mononuclear NiII complexes with ligands derived from doubly or triply deprotonated oxalodi­hydroxamic acid. In one of these complexes (Moroz et al., 2006[Moroz, Y. S., Gumienna-Kontecka, E., Fritsky, I. O., Dudarenko, N. M. & Świątek-Kozłowska, J. (2006). Acta Cryst. C62, m498-m500.]), the di­hydroxy­oxamidato trianion acts as a simple bidentate chelating ligand forming a square-planar complex. In the second (Świątek-Kozłowska et al., 2000[Świątek-Kozłowska, J., Fritsky, I. O., Dobosz, A., Karaczyn, A., Dudarenko, N. M., Sliva, T. Yu., Gumienna-Kontecka, E. & Jerzykiewicz, L. (2000). J. Chem. Soc. Dalton Trans. pp. 4064-4068.]), a square planar NiII complex again forms, but the di­hydroxy­oxamidato ligand also forms bridges to the potassium counter-ions generating a polymeric system. The structure presented here is the first example in which a di­hydroxy­oxamidato anion acts as a bridging ligand between two transition metals. The lack of crystal data for complexes with other transition metal cations may be associated with the ease of hydrolysis of the oxalodi­hydroxamic acid initiated by a metal salt solution.

5. Synthesis and crystallization

To the warm mixture containing 0.060 g (0.5 mmol) of oxalodi­hydroxamic acid and 0.370 g (1 mmol) of Cu(ClO4)2·6H2O in 10 ml of DMSO the solution of 2,2′-bi­pyridine (0.156 g, 1 mmol) in 10 ml of methanol was added upon stirring. The resulted solution was stirred for 1 h and then left for slow evaporation.

The resulting blue crystals suitable for X-ray analysis were isolated after one week. The crystals were washed with small amounts of 2-propanol and dried in air, yielding 0.255 g (28%) of the title compound.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3[link]. The OH hydrogen atom was located from a difference Fourier map and was refined isotropically. Other hydrogen atoms were positioned geometrically and were constrained to ride on their parent atoms, with C—H = 0.95–0.98 Å, and Uiso = 1.2–1.5 Ueq(parent atom). The highest peak is located 0.99 Å from atom Cu1 and the deepest hole is located 0.82 Å from atom Cu1.

Table 3
Experimental details

Crystal data
Chemical formula [Cu2(C2H2N2O4)(C10H8N2)2(C2H6OS)2](ClO4)2
Mr 912.66
Crystal system, space group Triclinic, P[\overline{1}]
Temperature (K) 100
a, b, c (Å) 7.3641 (2), 10.3759 (5), 12.1358 (5)
α, β, γ (°) 68.853 (2), 84.803 (3), 87.825 (3)
V3) 861.27 (6)
Z 1
Radiation type Mo Kα
μ (mm−1) 1.59
Crystal size (mm) 0.13 × 0.12 × 0.12
 
Data collection
Diffractometer Nonius KappaCCD
Absorption correction Multi-scan (SORTAV; Blessing, 1995[Blessing, R. H. (1995). Acta Cryst. A51, 33-38.])
Tmin, Tmax 0.789, 0.835
No. of measured, independent and observed [I > 2σ(I)] reflections 18205, 3943, 3351
Rint 0.039
(sin θ/λ)max−1) 0.649
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.087, 1.11
No. of reflections 3943
No. of parameters 241
H-atom treatment H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3) 0.74, −0.55
Computer programs: COLLECT (Bruker, 2004[Bruker (2004). COLLECT. Bruker AXS Inc., Madison, Wisconsin, USA.]), DENZO/SCALEPACK (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2014/7 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Chemical context top

Syntheses of complexes based on functionalized hydroxamic acids are of particular inter­est due to their non-trivial magnetic (Pavlishchuk et al., 2014) and luminescence (Jankolovits et al., 2011) properties, potential applications in bioinorganic modeling (Marmion et al., 2004), adsorption (Pavlishchuk et al., 2010, 2011a;), catalysis (Mezei et al., 2007) and the creation of recognition agents (Lim et al., 2011). The majority of complexes obtained with hydroxamic acids and additional donor ligands belong to different families of metallacrown coordination compounds (Mezei et al., 2007). Other topologies for polydentate hydroxamate-based complexes are more unusual (Gumienna-Kontecka et al., 2013; Golenya et al., 2014). Here we present the structure of the binuclear complex [Cu2(C10H8N2)2(µ-C2H2N2O4)(C2H6SO)2](ClO4)2 (I), obtained from oxalodi­hydroxamic acid and bi­pyridine in DMSO solution.

Structural commentary top

The title compound (I) consists of a centrosymmetric complex di-cation [Cu2(C10H8N2)2(µ-C2H2N2O4)(C2H6SO)2]2+ with two uncoordinating perchlorate counter-anions (Fig. 1). The two copper(II) cations are connected through a doubly deprotonated oxalodi­hydroxamic acid, which serves as a bridging ligand between the copper ions which are coordinated by two nitro­gen atoms from the 2,2'-bi­pyridine ligand, one carbonyl oxygen atom and the deprotonated hydroxamate nitro­gen atom from one half of the oxalodi­hydroxamato ligand and the O atom of a DMSO molecule. The oxalodi­hydroxamato dianion is in a trans-form, while for metallacrown formation the cis-form is preferred. The coordination spheres of the copper(II) cations are square-pyramidal (τ = 0.21; Addison et al., 1984) and the copper(II) ions deviate from the mean plane of the O1/N1/N2/N3 donor atoms by 0.1868 (2) Å. The separation between the copper (II) cations is 5.2949 (4) Å. The equatorial Cu—N and Cu—O distances are typical of those for copper(II) complexes with hydroxamate and oxime donor groups (Buvailo et al., 2012; Duda et al., 1997; Pavlishchuk et al., 2011b; Safyanova et al., 2015, Table 1). The elongated apical bond, Cu1—O2 (2.2516 (16) Å), compared to the Cu—O and Cu—N distances in the equatorial plane that range from 1.9848 (16) to 1.9966 (19) Å, Table 1, is most likely due to Jahn–Teller distortion.

The C—N and C—C bond lengths in the 2,2'-bi­pyridine ligands are also normal for 2-substituted pyridine derivatives (Krämer et al., 2000; Strotmeyer et al., 2003; Fritsky et al., 2004). The coordinated oxalo­hydroxamate dianion also has C—C, C—N, N—N bond lengths that are typical of N-deprotonated hydroxamate groups (Świątek-Kozłowska et al., 2000; Dobosz et al., 1999).

Supra­molecular features top

In the crystal structure, O5—H5O···O6 together with C12—H12A···O9 hydrogen bonds link the cations and associated perchlorate anions. An extensive series of other C—H···O contacts, Table 2, link the complex cations to other anions. The O2 atom of the DMSO ligand acts as a bifurcated acceptor forming C4—H4···O2 and C7—H7···O2 hydrogen bonds. These hydrogen bonds combine with ππ contacts between the N2/C6–C10 ring of the bi­pyridine and the Cu1/O1/C11/C11i/N3 ring formed by the chelating oxalodi­hydroxamate ligand with a centroid–centroid distance of 3.6371 (12) Å to stack the cations along the a-axis direction, Fig. 2.

Database survey top

A search in the Cambridge Structural Database (Version 5.35, May 2014; Groom & Allen, 2014) shows that there are seven reports devoted to the study of crystal structures of oxalodi­hydroxamic acid and its complexes. In the reported crystal structures of oxalodi­hydroxamic acid and its salts, the compound crystallized only in the trans-form. The bond distances in oxalodi­hydroxamic acid itself and in its ammonium and thallium salts do not differ significantly [C—C bonds are in the range 1.51 (2)–1.528 (3) Å, C=O 1.231 (3)–1.248 (3) Å, C—N 1.310 (4)–1.33 (2) Å while the N—O bond lengths vary from 1.36 (2) to 1.388 (1) Å; Lowe-Ma & Decker, 1986; Sameena Begum et al., 1987, 1988; Huang et al., 1991; Marsh, 1989). Only two structures of coordination compounds with di­hydroxy­oxamidato ligands were found. Both involved anionic mononuclear NiII complexes with ligands derived from doubly or triply deprotonated oxalodi­hydroxamic acid. In one of these complexes (Moroz et al., 2006), the di­hydroxy­oxamidato trianion acts as a simple bidentate chelating ligand forming a square-planar complex. In the second (Świątek-Kozłowska et al., 2000), a square planar NiII complex again forms, but the di­hydroxy­oxamidato ligand also forms bridges to the potassium(I) counter-ions generating a polymeric system. The structure presented here is the first example in which a di­hydroxy­oxamidato anion acts as a bridging ligand between two transition metals. The lack of crystal data for complexes with other transition metal cations may be associated with the ease of hydrolysis of the oxalodi­hydroxamic acid initiated by a metal salt solution.

Synthesis and crystallization top

To the warm mixture containing 0.060 g (0.5 mmol) of oxalodi­hydroxamic acid and 0.370 g (1 mmol) of Cu(ClO4)2.6H2O in 10 ml of DMSO the solution of 2,2 '-bi­pyridine (0.156 g, 1 mmol) in 10 ml of methanol was added upon stirring. The resulted solution was stirred for 1 h and then left for slow evaporation.

The resulting blue crystals suitable for X-ray analysis were isolated after one week. The crystals were washed with small amounts of 2-propanol and dried in air, yielding 0.255 g (28%) of the title compound.

Refinement top

The OH hydrogen atom was located from a difference Fourier map and was refined isotropically. Other hydrogen atoms were positioned geometrically and were constrained to ride on their parent atoms, with C—H = 0.95–0.98 Å, and Uiso = 1.2–1.5 Ueq(parent atom). The highest peak is located 0.99 Å from atom Cu1 and the deepest hole is located 0.82 Å from atom Cu1.

Structure description top

Syntheses of complexes based on functionalized hydroxamic acids are of particular inter­est due to their non-trivial magnetic (Pavlishchuk et al., 2014) and luminescence (Jankolovits et al., 2011) properties, potential applications in bioinorganic modeling (Marmion et al., 2004), adsorption (Pavlishchuk et al., 2010, 2011a;), catalysis (Mezei et al., 2007) and the creation of recognition agents (Lim et al., 2011). The majority of complexes obtained with hydroxamic acids and additional donor ligands belong to different families of metallacrown coordination compounds (Mezei et al., 2007). Other topologies for polydentate hydroxamate-based complexes are more unusual (Gumienna-Kontecka et al., 2013; Golenya et al., 2014). Here we present the structure of the binuclear complex [Cu2(C10H8N2)2(µ-C2H2N2O4)(C2H6SO)2](ClO4)2 (I), obtained from oxalodi­hydroxamic acid and bi­pyridine in DMSO solution.

The title compound (I) consists of a centrosymmetric complex di-cation [Cu2(C10H8N2)2(µ-C2H2N2O4)(C2H6SO)2]2+ with two uncoordinating perchlorate counter-anions (Fig. 1). The two copper(II) cations are connected through a doubly deprotonated oxalodi­hydroxamic acid, which serves as a bridging ligand between the copper ions which are coordinated by two nitro­gen atoms from the 2,2'-bi­pyridine ligand, one carbonyl oxygen atom and the deprotonated hydroxamate nitro­gen atom from one half of the oxalodi­hydroxamato ligand and the O atom of a DMSO molecule. The oxalodi­hydroxamato dianion is in a trans-form, while for metallacrown formation the cis-form is preferred. The coordination spheres of the copper(II) cations are square-pyramidal (τ = 0.21; Addison et al., 1984) and the copper(II) ions deviate from the mean plane of the O1/N1/N2/N3 donor atoms by 0.1868 (2) Å. The separation between the copper (II) cations is 5.2949 (4) Å. The equatorial Cu—N and Cu—O distances are typical of those for copper(II) complexes with hydroxamate and oxime donor groups (Buvailo et al., 2012; Duda et al., 1997; Pavlishchuk et al., 2011b; Safyanova et al., 2015, Table 1). The elongated apical bond, Cu1—O2 (2.2516 (16) Å), compared to the Cu—O and Cu—N distances in the equatorial plane that range from 1.9848 (16) to 1.9966 (19) Å, Table 1, is most likely due to Jahn–Teller distortion.

The C—N and C—C bond lengths in the 2,2'-bi­pyridine ligands are also normal for 2-substituted pyridine derivatives (Krämer et al., 2000; Strotmeyer et al., 2003; Fritsky et al., 2004). The coordinated oxalo­hydroxamate dianion also has C—C, C—N, N—N bond lengths that are typical of N-deprotonated hydroxamate groups (Świątek-Kozłowska et al., 2000; Dobosz et al., 1999).

In the crystal structure, O5—H5O···O6 together with C12—H12A···O9 hydrogen bonds link the cations and associated perchlorate anions. An extensive series of other C—H···O contacts, Table 2, link the complex cations to other anions. The O2 atom of the DMSO ligand acts as a bifurcated acceptor forming C4—H4···O2 and C7—H7···O2 hydrogen bonds. These hydrogen bonds combine with ππ contacts between the N2/C6–C10 ring of the bi­pyridine and the Cu1/O1/C11/C11i/N3 ring formed by the chelating oxalodi­hydroxamate ligand with a centroid–centroid distance of 3.6371 (12) Å to stack the cations along the a-axis direction, Fig. 2.

A search in the Cambridge Structural Database (Version 5.35, May 2014; Groom & Allen, 2014) shows that there are seven reports devoted to the study of crystal structures of oxalodi­hydroxamic acid and its complexes. In the reported crystal structures of oxalodi­hydroxamic acid and its salts, the compound crystallized only in the trans-form. The bond distances in oxalodi­hydroxamic acid itself and in its ammonium and thallium salts do not differ significantly [C—C bonds are in the range 1.51 (2)–1.528 (3) Å, C=O 1.231 (3)–1.248 (3) Å, C—N 1.310 (4)–1.33 (2) Å while the N—O bond lengths vary from 1.36 (2) to 1.388 (1) Å; Lowe-Ma & Decker, 1986; Sameena Begum et al., 1987, 1988; Huang et al., 1991; Marsh, 1989). Only two structures of coordination compounds with di­hydroxy­oxamidato ligands were found. Both involved anionic mononuclear NiII complexes with ligands derived from doubly or triply deprotonated oxalodi­hydroxamic acid. In one of these complexes (Moroz et al., 2006), the di­hydroxy­oxamidato trianion acts as a simple bidentate chelating ligand forming a square-planar complex. In the second (Świątek-Kozłowska et al., 2000), a square planar NiII complex again forms, but the di­hydroxy­oxamidato ligand also forms bridges to the potassium(I) counter-ions generating a polymeric system. The structure presented here is the first example in which a di­hydroxy­oxamidato anion acts as a bridging ligand between two transition metals. The lack of crystal data for complexes with other transition metal cations may be associated with the ease of hydrolysis of the oxalodi­hydroxamic acid initiated by a metal salt solution.

Synthesis and crystallization top

To the warm mixture containing 0.060 g (0.5 mmol) of oxalodi­hydroxamic acid and 0.370 g (1 mmol) of Cu(ClO4)2.6H2O in 10 ml of DMSO the solution of 2,2 '-bi­pyridine (0.156 g, 1 mmol) in 10 ml of methanol was added upon stirring. The resulted solution was stirred for 1 h and then left for slow evaporation.

The resulting blue crystals suitable for X-ray analysis were isolated after one week. The crystals were washed with small amounts of 2-propanol and dried in air, yielding 0.255 g (28%) of the title compound.

Refinement details top

The OH hydrogen atom was located from a difference Fourier map and was refined isotropically. Other hydrogen atoms were positioned geometrically and were constrained to ride on their parent atoms, with C—H = 0.95–0.98 Å, and Uiso = 1.2–1.5 Ueq(parent atom). The highest peak is located 0.99 Å from atom Cu1 and the deepest hole is located 0.82 Å from atom Cu1.

Computing details top

Data collection: COLLECT (Bruker, 2004); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The crystal structure of complex (I), showing the atom labeling. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. The crystal packing of complex (I).
µ-Oxalodihydroxamato-bis[(2,2'-bipyridyl)(dimethyl sulfoxide-κO)copper(II)] bis(perchlorate) top
Crystal data top
[Cu2(C2H2N2O4)(C10H8N2)2(C2H6OS)2](ClO4)2Z = 1
Mr = 912.66F(000) = 464
Triclinic, P1Dx = 1.760 Mg m3
a = 7.3641 (2) ÅMo Kα radiation, λ = 0.71069 Å
b = 10.3759 (5) ÅCell parameters from 26719 reflections
c = 12.1358 (5) Åθ = 1.0–27.5°
α = 68.853 (2)°µ = 1.59 mm1
β = 84.803 (3)°T = 100 K
γ = 87.825 (3)°Block, pale blue
V = 861.27 (6) Å30.13 × 0.12 × 0.12 mm
Data collection top
Nonius KappaCCD
diffractometer
3351 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.039
ω scansθmax = 27.5°, θmin = 2.8°
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
h = 89
Tmin = 0.789, Tmax = 0.835k = 1313
18205 measured reflectionsl = 1515
3943 independent reflections
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.034H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.087 w = 1/[σ2(Fo2) + (0.0388P)2 + 0.7097P]
where P = (Fo2 + 2Fc2)/3
S = 1.11(Δ/σ)max < 0.001
3943 reflectionsΔρmax = 0.74 e Å3
241 parametersΔρmin = 0.55 e Å3
Crystal data top
[Cu2(C2H2N2O4)(C10H8N2)2(C2H6OS)2](ClO4)2γ = 87.825 (3)°
Mr = 912.66V = 861.27 (6) Å3
Triclinic, P1Z = 1
a = 7.3641 (2) ÅMo Kα radiation
b = 10.3759 (5) ŵ = 1.59 mm1
c = 12.1358 (5) ÅT = 100 K
α = 68.853 (2)°0.13 × 0.12 × 0.12 mm
β = 84.803 (3)°
Data collection top
Nonius KappaCCD
diffractometer
3943 independent reflections
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
3351 reflections with I > 2σ(I)
Tmin = 0.789, Tmax = 0.835Rint = 0.039
18205 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0340 restraints
wR(F2) = 0.087H atoms treated by a mixture of independent and constrained refinement
S = 1.11Δρmax = 0.74 e Å3
3943 reflectionsΔρmin = 0.55 e Å3
241 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cu10.81268 (4)0.11133 (3)0.38671 (2)0.01840 (10)
Cl10.71265 (8)0.30071 (6)0.19039 (5)0.02481 (14)
S10.85060 (7)0.28499 (6)0.10324 (5)0.01997 (14)
O10.6724 (2)0.05948 (17)0.41752 (15)0.0210 (3)
O20.7106 (2)0.23761 (17)0.21002 (14)0.0221 (4)
O50.4262 (2)0.26749 (18)0.48100 (16)0.0243 (4)
H5O0.528 (6)0.253 (5)0.428 (4)0.083 (14)*
O60.6917 (3)0.3371 (2)0.31798 (18)0.0383 (5)
O70.5444 (3)0.3243 (2)0.1500 (2)0.0423 (5)
O80.8557 (3)0.3841 (2)0.16071 (18)0.0344 (4)
O90.7598 (3)0.15753 (19)0.13534 (19)0.0365 (5)
N10.9922 (3)0.2580 (2)0.36990 (17)0.0192 (4)
N21.0297 (3)0.0299 (2)0.32626 (17)0.0192 (4)
N30.3959 (3)0.1523 (2)0.51515 (17)0.0192 (4)
C10.9598 (3)0.3726 (3)0.3950 (2)0.0238 (5)
H10.84090.38830.42520.029*
C21.0948 (3)0.4694 (3)0.3781 (2)0.0255 (5)
H21.06830.54990.39670.031*
C31.2673 (3)0.4473 (3)0.3342 (2)0.0257 (5)
H31.36240.51080.32480.031*
C41.3010 (3)0.3309 (2)0.3038 (2)0.0222 (5)
H41.41800.31530.27080.027*
C51.1604 (3)0.2381 (2)0.3224 (2)0.0199 (5)
C61.1790 (3)0.1118 (2)0.2922 (2)0.0203 (5)
C71.3330 (3)0.0781 (3)0.2340 (2)0.0241 (5)
H71.43560.13760.21000.029*
C81.3359 (3)0.0434 (3)0.2112 (2)0.0261 (5)
H81.43980.06790.17050.031*
C91.1844 (3)0.1290 (3)0.2487 (2)0.0249 (5)
H91.18460.21400.23580.030*
C101.0341 (3)0.0888 (2)0.3050 (2)0.0231 (5)
H100.93000.14690.32950.028*
C110.5220 (3)0.0590 (2)0.4801 (2)0.0183 (5)
C120.8329 (4)0.1655 (3)0.0300 (2)0.0290 (6)
H12A0.85800.07190.08450.044*
H12B0.92150.18930.03950.044*
H12C0.70950.16960.00470.044*
C130.7529 (4)0.4328 (3)0.0024 (2)0.0266 (5)
H13A0.63200.40950.01730.040*
H13B0.83150.46220.07660.040*
H13C0.74140.50810.02860.040*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.01496 (15)0.02100 (16)0.01911 (16)0.00278 (10)0.00203 (10)0.00758 (12)
Cl10.0209 (3)0.0239 (3)0.0307 (3)0.0023 (2)0.0016 (2)0.0117 (2)
S10.0164 (3)0.0234 (3)0.0179 (3)0.0026 (2)0.0010 (2)0.0050 (2)
O10.0169 (8)0.0230 (8)0.0234 (9)0.0041 (6)0.0043 (6)0.0097 (7)
O20.0165 (8)0.0291 (9)0.0187 (8)0.0036 (7)0.0033 (6)0.0069 (7)
O50.0229 (9)0.0232 (9)0.0297 (10)0.0029 (7)0.0045 (7)0.0143 (8)
O60.0423 (12)0.0437 (12)0.0292 (10)0.0059 (9)0.0046 (9)0.0157 (9)
O70.0267 (10)0.0498 (13)0.0519 (13)0.0114 (9)0.0070 (9)0.0181 (11)
O80.0354 (11)0.0327 (10)0.0356 (11)0.0075 (8)0.0041 (8)0.0153 (9)
O90.0344 (11)0.0241 (10)0.0488 (13)0.0064 (8)0.0063 (9)0.0120 (9)
N10.0182 (9)0.0218 (10)0.0167 (9)0.0023 (7)0.0003 (7)0.0061 (8)
N20.0169 (9)0.0204 (10)0.0195 (10)0.0008 (7)0.0016 (8)0.0062 (8)
N30.0190 (10)0.0186 (9)0.0207 (10)0.0015 (7)0.0004 (8)0.0083 (8)
C10.0218 (12)0.0263 (13)0.0236 (12)0.0007 (9)0.0007 (10)0.0099 (10)
C20.0274 (13)0.0210 (12)0.0271 (13)0.0035 (10)0.0017 (10)0.0082 (10)
C30.0254 (13)0.0233 (12)0.0264 (13)0.0074 (10)0.0024 (10)0.0057 (10)
C40.0175 (11)0.0247 (12)0.0214 (12)0.0029 (9)0.0001 (9)0.0050 (10)
C50.0189 (11)0.0239 (12)0.0153 (11)0.0005 (9)0.0026 (9)0.0050 (9)
C60.0179 (11)0.0229 (12)0.0187 (11)0.0020 (9)0.0012 (9)0.0058 (9)
C70.0173 (11)0.0294 (13)0.0236 (13)0.0014 (9)0.0000 (9)0.0075 (10)
C80.0210 (12)0.0315 (13)0.0255 (13)0.0029 (10)0.0026 (10)0.0113 (11)
C90.0264 (13)0.0253 (13)0.0248 (13)0.0029 (10)0.0018 (10)0.0115 (10)
C100.0224 (12)0.0225 (12)0.0240 (12)0.0004 (9)0.0026 (10)0.0076 (10)
C110.0179 (11)0.0195 (11)0.0164 (11)0.0001 (9)0.0019 (9)0.0051 (9)
C120.0349 (14)0.0279 (13)0.0244 (13)0.0011 (11)0.0054 (11)0.0114 (11)
C130.0306 (13)0.0220 (12)0.0243 (13)0.0015 (10)0.0041 (10)0.0046 (10)
Geometric parameters (Å, º) top
Cu1—O11.9848 (16)C2—C31.376 (4)
Cu1—N21.985 (2)C2—H20.9500
Cu1—N3i1.986 (2)C3—C41.393 (4)
Cu1—N11.9966 (19)C3—H30.9500
Cu1—O22.2516 (16)C4—C51.388 (3)
Cl1—O91.4336 (19)C4—H40.9500
Cl1—O71.4339 (19)C5—C61.481 (3)
Cl1—O81.4401 (19)C6—C71.382 (3)
Cl1—O61.450 (2)C7—C81.384 (4)
S1—O21.5234 (17)C7—H70.9500
S1—C121.781 (3)C8—C91.390 (4)
S1—C131.783 (2)C8—H80.9500
O1—C111.286 (3)C9—C101.378 (4)
O5—N31.404 (3)C9—H90.9500
O5—H5O0.92 (5)C10—H100.9500
N1—C11.338 (3)C11—C11i1.486 (5)
N1—C51.359 (3)C12—H12A0.9800
N2—C101.345 (3)C12—H12B0.9800
N2—C61.355 (3)C12—H12C0.9800
N3—C111.296 (3)C13—H13A0.9800
N3—Cu1i1.986 (2)C13—H13B0.9800
C1—C21.389 (3)C13—H13C0.9800
C1—H10.9500
O1—Cu1—N290.36 (7)C2—C3—H3120.4
O1—Cu1—N3i82.73 (7)C4—C3—H3120.4
N2—Cu1—N3i165.41 (8)C5—C4—C3118.8 (2)
O1—Cu1—N1168.93 (7)C5—C4—H4120.6
N2—Cu1—N181.76 (8)C3—C4—H4120.6
N3i—Cu1—N1103.13 (8)N1—C5—C4121.6 (2)
O1—Cu1—O298.04 (6)N1—C5—C6114.7 (2)
N2—Cu1—O297.53 (7)C4—C5—C6123.7 (2)
N3i—Cu1—O296.15 (7)N2—C6—C7121.8 (2)
N1—Cu1—O290.72 (7)N2—C6—C5114.2 (2)
O9—Cl1—O7109.44 (13)C7—C6—C5124.1 (2)
O9—Cl1—O8109.53 (12)C6—C7—C8119.1 (2)
O7—Cl1—O8110.04 (13)C6—C7—H7120.4
O9—Cl1—O6109.19 (13)C8—C7—H7120.4
O7—Cl1—O6109.47 (13)C7—C8—C9119.0 (2)
O8—Cl1—O6109.16 (12)C7—C8—H8120.5
O2—S1—C12105.19 (11)C9—C8—H8120.5
O2—S1—C13105.82 (11)C10—C9—C8119.1 (2)
C12—S1—C1398.84 (13)C10—C9—H9120.5
C11—O1—Cu1110.68 (14)C8—C9—H9120.5
S1—O2—Cu1117.43 (9)N2—C10—C9122.2 (2)
N3—O5—H5O110 (3)N2—C10—H10118.9
C1—N1—C5119.0 (2)C9—C10—H10118.9
C1—N1—Cu1126.77 (16)O1—C11—N3127.6 (2)
C5—N1—Cu1114.11 (16)O1—C11—C11i119.6 (2)
C10—N2—C6118.8 (2)N3—C11—C11i112.8 (2)
C10—N2—Cu1126.04 (16)S1—C12—H12A109.5
C6—N2—Cu1114.74 (16)S1—C12—H12B109.5
C11—N3—O5116.51 (19)H12A—C12—H12B109.5
C11—N3—Cu1i114.16 (16)S1—C12—H12C109.5
O5—N3—Cu1i129.32 (14)H12A—C12—H12C109.5
N1—C1—C2122.0 (2)H12B—C12—H12C109.5
N1—C1—H1119.0S1—C13—H13A109.5
C2—C1—H1119.0S1—C13—H13B109.5
C3—C2—C1119.3 (2)H13A—C13—H13B109.5
C3—C2—H2120.4S1—C13—H13C109.5
C1—C2—H2120.4H13A—C13—H13C109.5
C2—C3—C4119.2 (2)H13B—C13—H13C109.5
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O5—H5O···O60.92 (5)2.12 (5)2.912 (3)144 (4)
C4—H4···O2ii0.952.423.359 (3)171
C7—H7···O2ii0.952.313.226 (3)162
C3—H3···O7iii0.952.503.239 (3)134
C13—H13A···O7iv0.982.563.409 (3)145
C13—H13C···O8v0.982.483.346 (3)148
C13—H13B···O8vi0.982.653.442 (3)138
C12—H12A···O90.982.363.175 (3)140
C8—H8···O9ii0.952.563.462 (3)159
C12—H12B···O9vi0.982.593.470 (3)150
Symmetry codes: (ii) x+1, y, z; (iii) x+1, y+1, z; (iv) x+1, y, z; (v) x, y+1, z; (vi) x+2, y, z.
Selected geometric parameters (Å, º) top
Cu1—O11.9848 (16)Cu1—O22.2516 (16)
Cu1—N21.985 (2)O1—C111.286 (3)
Cu1—N3i1.986 (2)O5—N31.404 (3)
Cu1—N11.9966 (19)
O1—Cu1—N290.36 (7)O1—Cu1—O298.04 (6)
O1—Cu1—N3i82.73 (7)N2—Cu1—O297.53 (7)
N2—Cu1—N181.76 (8)N3i—Cu1—O296.15 (7)
N3i—Cu1—N1103.13 (8)N1—Cu1—O290.72 (7)
Symmetry code: (i) x+1, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O5—H5O···O60.92 (5)2.12 (5)2.912 (3)144 (4)
C4—H4···O2ii0.952.423.359 (3)170.7
C7—H7···O2ii0.952.313.226 (3)161.8
C3—H3···O7iii0.952.503.239 (3)134.4
C13—H13A···O7iv0.982.563.409 (3)144.9
C13—H13C···O8v0.982.483.346 (3)147.5
C13—H13B···O8vi0.982.653.442 (3)137.8
C12—H12A···O90.982.363.175 (3)140.4
C8—H8···O9ii0.952.563.462 (3)159.2
C12—H12B···O9vi0.982.593.470 (3)149.9
Symmetry codes: (ii) x+1, y, z; (iii) x+1, y+1, z; (iv) x+1, y, z; (v) x, y+1, z; (vi) x+2, y, z.

Experimental details

Crystal data
Chemical formula[Cu2(C2H2N2O4)(C10H8N2)2(C2H6OS)2](ClO4)2
Mr912.66
Crystal system, space groupTriclinic, P1
Temperature (K)100
a, b, c (Å)7.3641 (2), 10.3759 (5), 12.1358 (5)
α, β, γ (°)68.853 (2), 84.803 (3), 87.825 (3)
V3)861.27 (6)
Z1
Radiation typeMo Kα
µ (mm1)1.59
Crystal size (mm)0.13 × 0.12 × 0.12
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(SORTAV; Blessing, 1995)
Tmin, Tmax0.789, 0.835
No. of measured, independent and
observed [I > 2σ(I)] reflections
18205, 3943, 3351
Rint0.039
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.087, 1.11
No. of reflections3943
No. of parameters241
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.74, 0.55

Computer programs: COLLECT (Bruker, 2004), DENZO/SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL2014/7 (Sheldrick, 2015), Mercury (Macrae et al., 2008), publCIF (Westrip, 2010).

 

References

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Volume 72| Part 2| February 2016| Pages 147-150
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