A one-dimensional coordination polymer based on a di-Schiff base supported trinuclear Cu^II subunit

A novel one-dimensional Cu^II coordination polymer, catena-poly[bis­(μ₄-3-{[2-(3-hydroxy-2-oxido­benzyl­idene)­hydrazinylidene]­methyl}­benzene-1,2-diolato)­dimethanol­tricopper(II)], [Cu₃(C₁₄H₁₀N₂O₄)₂(CH₃OH)₂]_n, (I), was constructed with a di-Schiff base supported centrosymmetric trinuclear Cu^II subunit. In the subunit, two peripheral symmetry-related Cu^II cations have square-pyramidal CuNO₄ geometry and the central third Cu^II cation lies on an inversion centre with octahedral CuN₂O₄ geometry. In (I), each partially deproton­ated di-Schiff base 3-{[2-(3-hydroxy-2-oxido­benzyl­idene)­hy­dra­zinyl­idene]­methyl}­benzene-1,2-diolate ligand (Hbcaz³⁻) acts as a hepta­dentate ligand to bind the Cu^II centres into chains along the a axis. A centrosymmetric Cu₂O₂ unit containing an asymmetrically bridging O atom, being axial at one Cu atom and equatorial at the other Cu atom, links the trinuclear Cu^II subunit into a one-dimensional chain, which is reinforced by intra­molecular phenol–methanol O—H...O and methanol–phenolate O—H...O hydrogen bonds. Interchain π–π stacking interactions between pyrocatechol units, with a distance of 3.5251 (18) Å, contribute to the stability of the crystal packing.

S1. Comment

Significant interest in the coordination chemistry of polydentate Schiff bases arises not only from their ability to construct metal–organic molecular architectures using their N- and O-atom donors (Li et al., 2003; Winpenny, 1998; Dong et al., 2000), but also from their potential applications in enantioselective processes (Sreerama et al., 2007), magnetic materials (Andruh 2011), DNA binding and cleavage activities (Kou et al., 2009), antimicrobial and antitumour activities (Poulter et al., 2011), antiradical activity (Puterova et al., 2011) and organic catalysts (Mukherjee et al., 2011). The design of these polydentate ligands remains an important element for assembling coordination polymers with fascinating topologies (Yang et al., 2009). Compared with the widely used mono-Schiff bases (Jeewoth et al., 1999), di-Schiff bases have two or more phenol –OH groups at the terminal positions and one aliphatic imine group between the aromatic rings, and therefore can exhibit diverse coordination modes of the metal ions and a concomitant tendency to form homo- and heteropolynuclear coordination complexes. In addition, they bear flexible skeletons, which can rotate freely around the C—N and N—N single bonds to meet the requirements of the coordination geometries of the metal ions in the assembly process.

The above considerations focused our attention on the polydentate di-Schiff base 3,3'-[(1E,2E)-hydrazinediylidenebis(methanylylidene)]di(benzene-1,2-diol) (H₄bcaz), which has been synthesized to assemble dinuclear triple-stranded helicates with Ti^IV and V^IV cations in the presence of alkali metal carbonate (Albrecht et al., 2003; Siegers et al., 2004). However, other metal complexes of this versatile di-Schiff base ligand have rarely been investigated. Polydentate Schiff base metal complexes usually contain mono- or binuclear metal subunits (Mandal et al., 1989; Ryan et al., 1998), but Schiff base metal complexes with higher nuclearity are very difficult to achieve (Zou et al., 2011). Remarkably, the H₄bcaz ligand has four phenol –OH and two imine N coordination sites, of which the four phenol –OH groups can deprotonate, depending on the reaction conditions, so its coordination modes are difficult to control and predict when coordinating to metal centres. Based on the above points and as part of our continuing investigations of coordination polymers (Sun et al., 2009; Dai et al., 2008), we have here used H₄bcaz to assemble a Cu^II one-dimensional coordination polymer, namely catena-poly[bis(µ₄-3-{[2-(3-hydroxy-2-oxidobenzylidene)hydrazinylidene]methyl}benzene-1,2-diolato)dimethanoltricopper(II)], (I), in which a triply deprotonated form of H₄bcaz binds three Cu^II cations to form a rare trinuclear Cu^II subunit.

As shown in Fig. 1, the asymmetric unit of (I) contains two crystallographically independent Cu^II centres, with one lying on a site of 1 symmetry, one Hbcaz^3- ligand and one coordinated methanol molecule. The central Cu1 atom is six-coordinated in an octahedral environment, in which the four in-plane donors are two phenolate O atoms and two imine N atoms belonging to two inversion-related Hbcaz^3- ligands, and the axial positions are occupied by O atoms from two methanol molecules. The coordinations of the outer Cu^II centres obviously have an identical CuNO₄ ligand environment, owing to inversion symmetry. This geometry of the outer Cu^II centres could be described as a slightly distorted square-pyramid comprising four phenolate O and one N imine atom. The distortion of the CuNO₄ square pyramid is indicated by the calculated value of the τ₅ parameter (Addison et al., 1984), which is 0.014 for atom Cu2 (for ideal square-pyramidal geometry, τ₅ = 0).

The Cu···Cu separation between nearest neighbours is 3.3396 (3) Å, which is longer than that of a similar trinuclear Cu^II subunit with acetate bridging at the axial positions (Chiari et al., 1985). The equatorial Cu—O bond lengths in the Cu^II coordination environment range from 1.8795 (17) to 1.9459 (16) Å and the axial Cu—O bond lengths, with an average value of 2.498 (9) Å, are obviously longer than those in the equatorial plane, indicating the Jahn–Teller effect for both Cu^II centres (Murphy & Hathaway, 2003). The Cu—N bond length has an average value of 1.99 (4) Å (Table 1). The ligand adopts a twisted conformation, with a C8—N2—N1—C7 torsion angle of 42.6 (3)° around the N2—N1 bond.

It is clear from the structure of (I) that each H₄bcaz molecule is partially deprotonated to form the Hbcaz^3- trianion, which acts as a pentadentate ligand (three phenolate O-atom donors and two imine N-atom donors) to chelate three Cu^II centres, giving a centrosymmetric trinuclear Cu^II subunit. One of the two axial Cu—O bonds plays a crucial role in extending the trinuclear Cu^II subunits into a one-dimensional chain along the a axis (Fig. 2). In addition, two types of intrachain O—H···O hydrogen bonds are observed within the one-dimensional chain, viz. phenol–methanol O—H···O and methanol–phenolate O—H···O (first and second entries, respectively, in Table 2), and these also play an important role in stabilizing the one-dimensional chain. According to graph-set notation (Bernstein et al., 1995), the two types of intrachain O—H···O hydrogen bond form a cyclic R₂²(9) motif. The crystal packing of the one-dimensional chains is primarily dominated by van der Waals interactions; no π–π or C—H···π interactions are observed in the crystal structure.

The linear trinuclear Cu^II subunit of (I) is very different from that of the previously reported discrete complex [Cu₃(H₂L)(L)].2H₂O, (II) [H₄L is N,N'-bis(3-hydroxysalicylidene)butane-1,4-diamine; Sanmart et al., 1999], where the three Cu^II centres are held together by two phenolate bridges to form an isosceles triangle with a Cu···Cu separation of 3.413 (3) Å, which is longer than the shortest Cu···Cu separation in (I). The formation of different trinuclear Cu^II subunits could be attributed to the existence of the long –(CH₂)₄– spacer between two imine groups in H₄L, which allows H₄L to twist and so achieves in (II) an isosceles triangle arrangement of three Cu^II centres, instead of the linear arrangement found in (I).

Related literature

For related literature, see: Addison et al. (1984); Albrecht et al. (2003); Andruh (2011); Bernstein et al. (1995); Chiari et al. (1985); Dai et al. (2008); Dong et al. (2000); Jeewoth et al. (1999); Kou et al. (2009); Li et al. (2003); Mandal et al. (1989); Mukherjee et al. (2011); Murphy & Hathaway (2003); Poulter et al. (2011); Puterova et al. (2011); Ryan et al. (1998); Sanmart et al. (1999); Siegers et al. (2004); Sreerama et al. (2007); Sun et al. (2009); Winpenny (1998); Yang et al. (2009); Zou et al. (2011).

S2. Experimental

H₄bcaz was synthesized by a modification of the procedure of Albrecht et al. (2003). 2,3-Dihydroxybenzaldehyde (2.76 g, 20.0 mmol), p-toluenesulfonic acid (20 mg) and hydrazine hydrate (600 mg, 12.00 mmol) were dissolved in toluene (68 ml). After heating overnight with continuous removal of water by distillation, and subsequent cooling to room temperature, the precipitated product was filtered off, giving 2.58 g (95% yield) of an orange solid. ¹H NMR (300MHz CDCl₃, δ, p.p.m.): 10.85 (s, br, 2H), 9.39 (s, br, 2H), 8.95 (s, 2H), 7.11 (dd, 2H), 6.94 (dd, 2H), 6.77 (t, 2H). A mixture of Cu(NO₃)₂.3H₂O (30 mg 0.12 mmol) and H₄bcaz (20 mg, 0.07 mmol) was dissolved in methanol (20 ml) and the solution was stirred until complete dissolution. The solution was then filtered and the filtrate was capped and allowed to stand at room temperature. Black crystals of (I) were collected after about one week (yield 47%, based on H₄bcaz).

S3. Refinement

C-bound H atoms were placed geometrically and treated as riding, with C—H = 0.96 (methyl) or 0.93 Å (aromatic and methylene), and with U_iso(H) = 1.2U_eq(C). The H atoms of the methanol ligand and the hydroxy group were found in a difference Fourier map and refined with an O—H distance restraint of 0.82 (2) Å and with U_iso(H) = 1.2U_eq(O).

Computing details

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

Figures

	Fig. 1. The structure of (I), showing the atom-numbering scheme and the coordination environment around the Cu^II centres. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) -x + 1, -y + 1, -z + 1; (ii) -x + 2, -y + 1, -z + 1.]
	Fig. 2. A representation of the one-dimensional chains of (I). Hydrogen bonds are shown as dashed lines.

catena-poly[bis(µ₄-3-{[2-(3-hydroxy-2- oxidobenzylidene)hydrazinylidene]methyl}benzene-1,2- diolato)dimethanoltricopper(II)]

Crystal data

[Cu3(C14H10N2O4)2(CH4O)2]	Z = 1
Mr = 793.17	F(000) = 401
Triclinic, P1	Dx = 1.785 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.9019 (5) Å	Cell parameters from 5094 reflections
b = 10.2333 (7) Å	θ = 4.5–54.8°
c = 10.4441 (7) Å	µ = 2.21 mm^−1
α = 112.281 (3)°	T = 298 K
β = 95.373 (4)°	Block, black
γ = 104.862 (3)°	0.12 × 0.10 × 0.10 mm
V = 737.93 (8) Å^3

Data collection

Bruker SMART APEXII CCD area-detector diffractometer	3323 independent reflections
Radiation source: fine-focus sealed tube	2686 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
ω scans	θmax = 27.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −8→10
Tmin = 0.777, Tmax = 0.809	k = −13→11
9076 measured reflections	l = −11→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.093	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0539P)^2 + 0.1408P] where P = (Fo^2 + 2Fc^2)/3
3323 reflections	(Δ/σ)max = 0.001
221 parameters	Δρmax = 0.47 e Å^−3
2 restraints	Δρmin = −0.25 e Å^−3

Special details

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cu1	0.5000	0.5000	0.5000	0.03200 (13)
Cu2	0.90273 (4)	0.49267 (3)	0.62012 (3)	0.03312 (12)
C1	0.8328 (3)	0.2326 (3)	0.3886 (3)	0.0345 (5)
C2	0.6733 (3)	0.2699 (3)	0.3796 (3)	0.0321 (5)
C3	0.5243 (3)	0.1756 (3)	0.2708 (3)	0.0339 (5)
C4	0.5307 (4)	0.0352 (3)	0.1766 (3)	0.0412 (6)
H4B	0.4306	−0.0315	0.1063	0.049*
C5	0.6825 (4)	−0.0021 (3)	0.1886 (3)	0.0469 (7)
H5A	0.6851	−0.0947	0.1266	0.056*
C6	0.8340 (4)	0.0960 (3)	0.2922 (3)	0.0424 (6)
H6A	0.9377	0.0695	0.2968	0.051*
C7	0.3712 (3)	0.2182 (3)	0.2412 (3)	0.0351 (6)
H7A	0.2764	0.1460	0.1689	0.042*
C8	0.1539 (3)	0.3233 (3)	0.1124 (3)	0.0368 (6)
H8A	0.2303	0.2829	0.0589	0.044*
C9	−0.0040 (3)	0.3272 (3)	0.0382 (3)	0.0374 (6)
C10	−0.1293 (3)	0.3860 (3)	0.1080 (3)	0.0365 (6)
C11	−0.2855 (3)	0.3828 (3)	0.0252 (3)	0.0428 (6)
C12	−0.3109 (4)	0.3246 (3)	−0.1196 (3)	0.0498 (7)
H12A	−0.4128	0.3236	−0.1728	0.060*
C13	−0.1858 (4)	0.2667 (3)	−0.1886 (3)	0.0533 (8)
H13A	−0.2045	0.2281	−0.2869	0.064*
C14	−0.0365 (4)	0.2669 (3)	−0.1118 (3)	0.0464 (7)
H14A	0.0453	0.2270	−0.1584	0.056*
C15	0.2933 (5)	0.1908 (4)	0.5662 (4)	0.0689 (10)
H15C	0.2137	0.1290	0.4756	0.083*
H15B	0.2452	0.1642	0.6373	0.083*
H15A	0.4085	0.1766	0.5632	0.083*
N1	0.3524 (3)	0.3479 (2)	0.3057 (2)	0.0318 (5)
N2	0.1996 (3)	0.3718 (2)	0.2492 (2)	0.0336 (5)
O1	0.9742 (2)	0.33502 (19)	0.48878 (19)	0.0365 (4)
O2	0.6773 (2)	0.40128 (19)	0.48112 (18)	0.0350 (4)
O3	−0.1134 (2)	0.4491 (2)	0.24474 (19)	0.0400 (4)
O4	−0.4057 (3)	0.4399 (3)	0.0925 (2)	0.0618 (6)
H4A	−0.355 (4)	0.487 (4)	0.181 (2)	0.074*
O5	0.3112 (3)	0.3406 (3)	0.5992 (2)	0.0536 (5)
H5B	0.214 (3)	0.343 (4)	0.575 (4)	0.064*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0252 (2)	0.0350 (2)	0.0318 (2)	0.01314 (18)	0.00417 (17)	0.00799 (18)
Cu2	0.02530 (17)	0.0407 (2)	0.03297 (19)	0.01405 (14)	0.00632 (13)	0.01266 (14)
C1	0.0331 (13)	0.0376 (14)	0.0363 (14)	0.0136 (11)	0.0107 (11)	0.0169 (11)
C2	0.0310 (13)	0.0326 (13)	0.0346 (13)	0.0129 (10)	0.0112 (10)	0.0133 (11)
C3	0.0325 (13)	0.0321 (13)	0.0343 (13)	0.0101 (11)	0.0073 (10)	0.0111 (11)
C4	0.0420 (15)	0.0340 (14)	0.0407 (15)	0.0122 (12)	0.0037 (12)	0.0094 (12)
C5	0.0566 (18)	0.0357 (14)	0.0461 (16)	0.0232 (13)	0.0102 (14)	0.0094 (12)
C6	0.0412 (15)	0.0435 (15)	0.0463 (16)	0.0239 (13)	0.0102 (12)	0.0157 (13)
C7	0.0293 (13)	0.0373 (14)	0.0349 (13)	0.0096 (11)	0.0054 (10)	0.0121 (11)
C8	0.0337 (13)	0.0383 (14)	0.0342 (14)	0.0113 (11)	0.0083 (11)	0.0105 (11)
C9	0.0342 (14)	0.0386 (14)	0.0351 (14)	0.0080 (11)	0.0021 (11)	0.0144 (11)
C10	0.0308 (13)	0.0362 (14)	0.0401 (15)	0.0037 (11)	0.0014 (11)	0.0194 (12)
C11	0.0333 (14)	0.0424 (15)	0.0504 (17)	0.0067 (12)	−0.0024 (12)	0.0231 (13)
C12	0.0418 (16)	0.0508 (17)	0.0474 (17)	0.0036 (14)	−0.0092 (13)	0.0221 (14)
C13	0.062 (2)	0.0501 (18)	0.0359 (15)	0.0074 (15)	−0.0029 (14)	0.0146 (13)
C14	0.0473 (17)	0.0468 (16)	0.0377 (15)	0.0116 (13)	0.0044 (13)	0.0131 (13)
C15	0.069 (2)	0.075 (2)	0.076 (2)	0.027 (2)	0.0076 (19)	0.044 (2)
N1	0.0242 (10)	0.0387 (12)	0.0311 (11)	0.0113 (9)	0.0057 (8)	0.0123 (9)
N2	0.0259 (10)	0.0390 (12)	0.0339 (11)	0.0119 (9)	0.0050 (9)	0.0125 (9)
O1	0.0278 (9)	0.0396 (10)	0.0384 (10)	0.0146 (8)	0.0049 (7)	0.0104 (8)
O2	0.0258 (9)	0.0362 (9)	0.0368 (10)	0.0135 (7)	0.0035 (7)	0.0071 (8)
O3	0.0299 (9)	0.0553 (12)	0.0387 (10)	0.0189 (9)	0.0065 (8)	0.0206 (9)
O4	0.0429 (12)	0.0934 (18)	0.0588 (13)	0.0326 (12)	0.0059 (11)	0.0360 (13)
O5	0.0373 (11)	0.0642 (14)	0.0684 (14)	0.0226 (11)	0.0104 (10)	0.0334 (12)

Geometric parameters (Å, º)

Cu1—O2^i	1.9103 (16)	C7—H7A	0.9300
Cu1—O2	1.9103 (16)	C8—N2	1.300 (3)
Cu1—N1	2.033 (2)	C8—C9	1.423 (4)
Cu1—N1^i	2.033 (2)	C8—H8A	0.9300
Cu1—O5	2.507 (2)	C9—C10	1.408 (4)
Cu1—Cu2	3.3396 (3)	C9—C14	1.419 (4)
Cu2—O3^i	1.8795 (17)	C10—O3	1.303 (3)
Cu2—O1	1.9332 (17)	C10—C11	1.425 (3)
Cu2—O2	1.9459 (16)	C11—O4	1.355 (4)
Cu2—N2^i	1.946 (2)	C11—C12	1.371 (4)
Cu2—O1^ii	2.4894 (18)	C12—C13	1.400 (4)
C1—O1	1.338 (3)	C12—H12A	0.9300
C1—C6	1.381 (4)	C13—C14	1.362 (4)
C1—C2	1.413 (3)	C13—H13A	0.9300
C2—O2	1.350 (3)	C14—H14A	0.9300
C2—C3	1.394 (3)	C15—O5	1.403 (4)
C3—C4	1.417 (3)	C15—H15C	0.9600
C3—C7	1.433 (3)	C15—H15B	0.9600
C4—C5	1.358 (4)	C15—H15A	0.9600
C4—H4B	0.9300	N1—N2	1.411 (3)
C5—C6	1.389 (4)	N2—Cu2^i	1.946 (2)
C5—H5A	0.9300	O3—Cu2^i	1.8795 (17)
C6—H6A	0.9300	O4—H4A	0.859 (18)
C7—N1	1.296 (3)	O5—H5B	0.799 (17)
O2^i—Cu1—O2	180.000 (1)	N2—C8—H8A	117.4
O2^i—Cu1—N1	89.20 (7)	C9—C8—H8A	117.4
O2—Cu1—N1	90.80 (7)	C10—C9—C14	119.2 (2)
O2^i—Cu1—N1^i	90.80 (7)	C10—C9—C8	122.5 (2)
O2—Cu1—N1^i	89.20 (7)	C14—C9—C8	118.3 (2)
N1—Cu1—N1^i	180.0	O3—C10—C9	125.6 (2)
O2^i—Cu1—O5	85.99 (7)	O3—C10—C11	115.6 (2)
O2—Cu1—O5	94.01 (7)	C9—C10—C11	118.8 (2)
N1—Cu1—O5	86.87 (8)	O4—C11—C12	121.2 (3)
N1^i—Cu1—O5	93.13 (8)	O4—C11—C10	118.7 (3)
O3^i—Cu2—O1	90.67 (8)	C12—C11—C10	120.1 (3)
O3^i—Cu2—O2	170.80 (8)	C11—C12—C13	121.0 (3)
O1—Cu2—O2	84.41 (7)	C11—C12—H12A	119.5
O3^i—Cu2—N2^i	93.42 (8)	C13—C12—H12A	119.5
O1—Cu2—N2^i	171.60 (8)	C14—C13—C12	119.9 (3)
O2—Cu2—N2^i	90.51 (7)	C14—C13—H13A	120.0
O3^i—Cu2—O1^ii	95.81 (7)	C12—C13—H13A	120.0
O1—Cu2—O1^ii	92.16 (7)	C13—C14—C9	121.0 (3)
O2—Cu2—O1^ii	92.15 (7)	C13—C14—H14A	119.5
N2^i—Cu2—O1^ii	94.71 (7)	C9—C14—H14A	119.5
O1—C1—C6	124.6 (2)	O5—C15—H15C	109.5
O1—C1—C2	117.0 (2)	O5—C15—H15B	109.5
C6—C1—C2	118.4 (2)	H15C—C15—H15B	109.5
O2—C2—C3	123.5 (2)	O5—C15—H15A	109.5
O2—C2—C1	115.6 (2)	H15C—C15—H15A	109.5
C3—C2—C1	120.8 (2)	H15B—C15—H15A	109.5
C2—C3—C4	118.5 (2)	C7—N1—N2	117.0 (2)
C2—C3—C7	123.3 (2)	C7—N1—Cu1	123.56 (17)
C4—C3—C7	117.9 (2)	N2—N1—Cu1	118.36 (15)
C5—C4—C3	120.2 (2)	C8—N2—N1	118.2 (2)
C5—C4—H4B	119.9	C8—N2—Cu2^i	122.88 (18)
C3—C4—H4B	119.9	N1—N2—Cu2^i	117.85 (15)
C4—C5—C6	120.9 (3)	C1—O1—Cu2	110.64 (15)
C4—C5—H5A	119.5	C2—O2—Cu1	129.16 (15)
C6—C5—H5A	119.5	C2—O2—Cu2	110.84 (15)
C1—C6—C5	121.0 (3)	Cu1—O2—Cu2	120.00 (8)
C1—C6—H6A	119.5	C10—O3—Cu2^i	125.08 (16)
C5—C6—H6A	119.5	C11—O4—H4A	106 (3)
N1—C7—C3	126.2 (2)	C15—O5—Cu1	125.9 (2)
N1—C7—H7A	116.9	C15—O5—H5B	107 (3)
C3—C7—H7A	116.9	Cu1—O5—H5B	101 (2)
N2—C8—C9	125.2 (2)
C7—N1—N2—C8	−42.6 (3)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4A···O3	0.86 (2)	2.14 (3)	2.638 (3)	117 (3)
O4—H4A···O5^iii	0.86 (2)	2.23 (2)	3.029 (3)	154 (3)
O5—H5B···O1^iv	0.80 (2)	1.99 (2)	2.779 (3)	173 (4)

Symmetry codes: (iii) −x, −y+1, −z+1; (iv) x−1, y, z.