Diaqua­bis­(dimethyl sulfoxide-κO)bis(saccharinato-κN)cobalt(II)

Potwana, F.S.W.; Van Zyl, W.E.

doi:10.1107/S1600536811045296

metal-organic compounds

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ISSN: 2056-9890

Volume 67| Part 12| December 2011| Pages m1667-m1668

https://doi.org/10.1107/S1600536811045296

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Diaquabis(dimethyl sulfoxide-κO)bis(saccharinato-κN)cobalt(II)

Fezile S. W. Potwana ^a and Werner E. Van Zyl ^a ^*

^aSchool of Chemistry, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
^*Correspondence e-mail: vanzylw@ukzn.ac.za

(Received 18 October 2011; accepted 28 October 2011; online 5 November 2011)

The title complex, [Co(C₇H₄NO₃S)₂(C₂H₆OS)₂(H₂O)₂], contains a Co²⁺ cation in an octahedral coordination environment. The metal atom is surrounded by two different neutral ligands, namely dimethylsulfoxide (DMSO) and water, each coordinating through the O atom. The anionic saccharinate (sac; 1,1,3-trioxo-2,3-dihydro-1λ⁶,2-benzothiazol-2-ide) ligand coordinates through the N atom. Each of the three similar ligand pairs is in a trans configuration with respect to each other. The Co atom lies on a crystallographic center of symmetry and the octahedral geometry is not significantly distorted. A short O—H⋯O hydrogen bond is present between a water H atom and the ketone O atom; two longer hydrogen bonds (intra- and intermolecular) are also present between a water H and a sulfonic O atom, forming a supramolecular assembly through head-to-tail aggregation between adjacent complexes.

Related literature

For a general review article on the coordination chemistry of saccharinate ligands, see: Baran & Yilmaz (2006 ). For cobalt(II) saccharinate complexes, see: Deng et al. (2008 ) and for cobalt(II) complexes with saccharinate as a non-coordinating ligand, see: Batsanov et al. (2011 ). For the preparation of cobalt(II) and other divalent metal precursor complexes, see: Haider et al. (1985 ).

Experimental

Crystal data

[Co(C₇H₄NO₃S)₂(C₂H₆OS)₂(H₂O)₂]
M_r = 615.56
Monoclinic, P 2₁ /c
a = 10.2304 (3) Å
b = 15.1418 (6) Å
c = 7.8615 (3) Å
β = 98.068 (2)°
V = 1205.75 (8) Å³
Z = 2
Mo Kα radiation
μ = 1.12 mm⁻¹
T = 173 K
0.27 × 0.15 × 0.10 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.753, T_max = 0.897
5888 measured reflections
3000 independent reflections
2301 reflections with I > 2σ(I)
R_int = 0.018

Refinement

R[F² > 2σ(F²)] = 0.030
wR(F²) = 0.081
S = 1.06
3000 reflections
171 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.71 e Å⁻³
Δρ_min = −0.49 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H5A⋯O3ⁱ	0.98	1.73	2.646 (2)	155 (3)
O5—H5B⋯O1	0.98	2.09	2.803 (2)	128 (2)
O5—H5B⋯O1ⁱⁱ	0.98	2.06	2.904 (2)	143 (2)
C8—H8B⋯O5ⁱⁱⁱ	0.98	2.54	3.277 (2)	132
C8—H8B⋯O4^iv	0.98	2.51	3.383 (2)	148
C9—H9A⋯O3ⁱ	0.98	2.58	3.363 (2)	137
C9—H9B⋯O4^iv	0.98	2.58	3.432 (2)	146
Symmetry codes: (i) -x+1, -y+1, -z; (ii) -x+1, -y+1, -z+1; (iii) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iv) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: COLLECT (Nonius, 1998 ); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997 ); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536811045296/br2180sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811045296/br2180Isup2.hkl

checkCIF report

Comment top

Saccharin (o-sulfobenzimide; 1,2-benzothiazole-3(2H)-one 1,1-dioxide; Hsac) is a widely used artificial sweetening agent. The imino hydrogen is acidic and can be readily deprotonated. The coordination chemistry of this anion is versatile due to the different coordination sites to metallic centers it can accommodate, i.e., one N, one O (carbonylic) and two O (sulfonic) atoms. These donor atoms of the anion can thus readily generate either N– or O-monodentate or bidentate (N, O) coordination. Saccharin is normally used as the sodium or calcium salt which dramatically improves water solubility. Most metal complexes contain the deprotonated form of saccharin, and this saccharinate anion (sac) is commercially available as the sodium salt, used in the present study. The reaction of sodium saccharinate with the first row divalent transition metal ions results in coordination complexes with general formula [M(sac)₂(H₂O)₄].2H₂O, (M = V, Cr, Mn, Fe, Co, Ni, Cu, Zn), which all show a clear preference to bind through the deprotonated anionic N-atom (Baran and Yilmaz, 2006). These octahedral complexes contain two N-bonded sac ligands in trans positions, and complexes of the type [M(sac)₂(H₂O)₄].2H₂O are thus commonly used as precursors in the synthesis of mixed-ligand saccharinate complexes. The aqua ligands in these metal complexes are labile and readily displaced by direct reaction of neutral ligands. The addition of the ligands to the solutions of the complexes usually results in the substitution of all four aqua ligands, thereby forming stable new mixed-ligand complexes. In cases where the incoming neutral ligand is relatively bulky, as in the present study, it causes steric hindrance and only two of the four aqua ligands become displaced in order for the Co center to remain octahedral. Although there are a number of Co(II) saccharinate complexes previously reported (Batsanov et al., 2011, and refs. therein), the present study reports the first example of a structurally characterized Co(II) complex that contains both saccharinate and dmso ligands.

Related literature top

For a general review article on the coordination chemistry of saccharinate ligands, see: Baran & Yilmaz (2006). For cobalt(II) saccharinate complexes, see: Deng et al. (2008) and for cobalt(II) complexes with saccharinate as a non-coordinating ligand, see: Batsanov et al. (2011). For the preparation of cobalt(II) and other divalent metal precursor complexes, see: Haider et al. (1985).

Experimental top

[Co(sac)₂(H₂O)₄].2H₂O was prepared as per literature method (Haider et al., 1985). The red crystals of [Co(sac)₂(H₂O)₄].2H₂O (0.932 g; 1.80 mmol) was placed in a 100 ml beaker and dissolved in excess amount of dimethyl sulfoxide (dmso) (20 ml). The reaction mixture was gently heated on a heating plate with stirring to reduce the volume of dmso to ~7 ml. The beaker was removed from the heat source and allowed to stand for 10 days during which time large light red blocky crystals of the title compound were obtained. Yield (1.00 g, 93.0%). Mp: 393 K; 120 ° C. IR-ATR (cm^-1): 3486.98, 3005.41 n(OH); 1618 n(C=O); 1584, 1460 n(C=C); 1256 n(O=S=O); 1141, 949 n(S=O). No NMR data were recorded due to the paramagnetic nature of the Co(II) complex. Single crystals were obtained by slow evaporation of dmso solvent.

Structure description top

For a general review article on the coordination chemistry of saccharinate ligands, see: Baran & Yilmaz (2006). For cobalt(II) saccharinate complexes, see: Deng et al. (2008) and for cobalt(II) complexes with saccharinate as a non-coordinating ligand, see: Batsanov et al. (2011). For the preparation of cobalt(II) and other divalent metal precursor complexes, see: Haider et al. (1985).

Computing details top

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. The ORTEP molecular structure of the title complex, shown with 50% probability ellipsoids.

Diaquabis(dimethyl sulfoxide-κO)bis(1,1,3-trioxo-2,3- dihydro-1λ⁶,2-benzothiazol-2-ido-κN)cobalt(II) top

Crystal data top

[Co(C₇H₄NO₃S)₂(C₂H₆OS)₂(H₂O)₂]	F(000) = 634
M_r = 615.56	D_x = 1.695 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5888 reflections
a = 10.2304 (3) Å	θ = 2.4–28.3°
b = 15.1418 (6) Å	µ = 1.12 mm⁻¹
c = 7.8615 (3) Å	T = 173 K
β = 98.068 (2)°	Block, light red
V = 1205.75 (8) Å³	0.27 × 0.15 × 0.10 mm
Z = 2

Data collection top

Nonius KappaCCD diffractometer	3000 independent reflections
Radiation source: fine-focus sealed tube	2301 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.018
1.2° φ scans and ω scans	θ_max = 28.3°, θ_min = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −13→13
T_min = 0.753, T_max = 0.897	k = −20→20
5888 measured reflections	l = −10→10

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.030	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.081	w = 1/[σ²(F_o²) + (0.0497P)²] where P = (F_o² + 2F_c²)/3
S = 1.06	(Δ/σ)_max < 0.001
3000 reflections	Δρ_max = 0.71 e Å⁻³
171 parameters	Δρ_min = −0.49 e Å⁻³
2 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0082 (11)

Crystal data top

[Co(C₇H₄NO₃S)₂(C₂H₆OS)₂(H₂O)₂]	V = 1205.75 (8) Å³
M_r = 615.56	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 10.2304 (3) Å	µ = 1.12 mm⁻¹
b = 15.1418 (6) Å	T = 173 K
c = 7.8615 (3) Å	0.27 × 0.15 × 0.10 mm
β = 98.068 (2)°

Data collection top

Nonius KappaCCD diffractometer	3000 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	2301 reflections with I > 2σ(I)
T_min = 0.753, T_max = 0.897	R_int = 0.018
5888 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.030	2 restraints
wR(F²) = 0.081	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.71 e Å⁻³
3000 reflections	Δρ_min = −0.49 e Å⁻³
171 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.

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 > σ(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 (Å²) top

	x	y	z	U_iso*/U_eq
Co1	0.5000	0.5000	0.0000	0.01579 (11)
S1	0.27267 (4)	0.50687 (3)	0.28359 (5)	0.01976 (12)
S2	0.51966 (4)	0.68690 (3)	0.19988 (6)	0.02130 (13)
O1	0.37735 (12)	0.46878 (9)	0.40314 (15)	0.0278 (3)
O2	0.24179 (13)	0.59763 (9)	0.31675 (17)	0.0305 (3)
O3	0.18849 (12)	0.43540 (8)	−0.16410 (15)	0.0251 (3)
O4	0.51937 (12)	0.63688 (8)	0.03114 (15)	0.0222 (3)
O5	0.60377 (12)	0.47674 (8)	0.24012 (16)	0.0218 (3)
H5A	0.6902 (13)	0.5053 (17)	0.246 (4)	0.087 (11)*
H5B	0.570 (3)	0.4869 (16)	0.3492 (18)	0.062 (8)*
N1	0.30080 (14)	0.49352 (9)	0.08660 (19)	0.0193 (3)
C1	0.13015 (16)	0.44084 (11)	0.2695 (2)	0.0192 (4)
C2	0.05764 (17)	0.41415 (12)	0.3962 (2)	0.0240 (4)
H2	0.0820	0.4307	0.5129	0.029*
C3	−0.05215 (19)	0.36209 (12)	0.3448 (3)	0.0296 (4)
H3	−0.1056	0.3433	0.4275	0.036*
C4	−0.08537 (19)	0.33692 (14)	0.1742 (3)	0.0324 (5)
H4	−0.1611	0.3010	0.1428	0.039*
C5	−0.01053 (17)	0.36300 (12)	0.0487 (2)	0.0259 (4)
H5	−0.0334	0.3452	−0.0676	0.031*
C6	0.09874 (16)	0.41590 (11)	0.0990 (2)	0.0196 (4)
C7	0.19847 (16)	0.44925 (11)	−0.0076 (2)	0.0192 (4)
C8	0.39348 (18)	0.76726 (13)	0.1549 (2)	0.0296 (4)
H8A	0.4055	0.7992	0.0498	0.044*
H8B	0.3981	0.8089	0.2509	0.044*
H8C	0.3072	0.7380	0.1391	0.044*
C9	0.65935 (19)	0.75778 (13)	0.2148 (3)	0.0348 (5)
H9A	0.7402	0.7223	0.2331	0.052*
H9B	0.6581	0.7985	0.3114	0.052*
H9C	0.6567	0.7915	0.1080	0.052*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Co1	0.01863 (18)	0.01480 (18)	0.01393 (18)	−0.00075 (12)	0.00224 (13)	−0.00099 (12)
S1	0.0190 (2)	0.0247 (2)	0.0160 (2)	−0.00384 (16)	0.00399 (17)	−0.00383 (16)
S2	0.0269 (2)	0.0180 (2)	0.0189 (2)	−0.00124 (17)	0.00312 (17)	−0.00226 (17)
O1	0.0216 (7)	0.0433 (8)	0.0182 (7)	−0.0027 (6)	0.0013 (5)	−0.0020 (6)
O2	0.0354 (8)	0.0253 (7)	0.0324 (8)	−0.0053 (6)	0.0103 (6)	−0.0102 (6)
O3	0.0246 (6)	0.0333 (7)	0.0172 (6)	−0.0048 (5)	0.0023 (5)	−0.0029 (5)
O4	0.0319 (7)	0.0156 (6)	0.0195 (6)	−0.0010 (5)	0.0049 (5)	−0.0023 (5)
O5	0.0237 (7)	0.0248 (6)	0.0169 (6)	−0.0007 (5)	0.0034 (5)	0.0001 (5)
N1	0.0181 (7)	0.0241 (8)	0.0162 (7)	−0.0029 (6)	0.0042 (6)	−0.0019 (6)
C1	0.0188 (8)	0.0185 (8)	0.0202 (9)	0.0005 (7)	0.0026 (7)	−0.0017 (7)
C2	0.0255 (9)	0.0261 (9)	0.0216 (9)	0.0020 (8)	0.0077 (8)	−0.0009 (8)
C3	0.0288 (10)	0.0325 (11)	0.0301 (11)	−0.0060 (8)	0.0129 (8)	0.0005 (8)
C4	0.0263 (10)	0.0361 (11)	0.0351 (11)	−0.0113 (9)	0.0057 (8)	−0.0021 (9)
C5	0.0231 (9)	0.0301 (11)	0.0237 (9)	−0.0043 (7)	0.0005 (8)	−0.0050 (8)
C6	0.0180 (8)	0.0205 (9)	0.0200 (9)	0.0017 (7)	0.0019 (7)	0.0004 (7)
C7	0.0189 (8)	0.0209 (9)	0.0176 (9)	0.0022 (7)	0.0022 (7)	0.0011 (7)
C8	0.0351 (11)	0.0248 (10)	0.0291 (11)	0.0070 (8)	0.0049 (9)	−0.0041 (8)
C9	0.0332 (11)	0.0313 (11)	0.0399 (12)	−0.0098 (9)	0.0058 (9)	−0.0143 (9)

Geometric parameters (Å, º) top

Co1—O5ⁱ	2.0620 (12)	C1—C2	1.383 (2)
Co1—O5	2.0620 (12)	C1—C6	1.386 (2)
Co1—O4ⁱ	2.0932 (12)	C2—C3	1.385 (3)
Co1—O4	2.0932 (12)	C2—H2	0.9500
Co1—N1ⁱ	2.2396 (14)	C3—C4	1.390 (3)
Co1—N1	2.2396 (14)	C3—H3	0.9500
S1—O2	1.4420 (14)	C4—C5	1.389 (3)
S1—O1	1.4423 (13)	C4—H4	0.9500
S1—N1	1.6270 (15)	C5—C6	1.387 (2)
S1—C1	1.7586 (17)	C5—H5	0.9500
S2—O4	1.5272 (12)	C6—C7	1.496 (2)
S2—C8	1.7731 (18)	C8—H8A	0.9800
S2—C9	1.7779 (18)	C8—H8B	0.9800
O3—C7	1.2383 (19)	C8—H8C	0.9800
O5—H5A	0.980 (2)	C9—H9A	0.9800
O5—H5B	0.980 (2)	C9—H9B	0.9800
N1—C7	1.370 (2)	C9—H9C	0.9800

O5ⁱ—Co1—O4ⁱ	91.94 (5)	C1—C2—C3	116.79 (17)
O5—Co1—O4ⁱ	88.06 (5)	C1—C2—H2	121.6
O5ⁱ—Co1—O4	88.06 (5)	C3—C2—H2	121.6
O5—Co1—O4	91.94 (5)	C2—C3—C4	121.08 (18)
O5ⁱ—Co1—N1ⁱ	95.03 (5)	C2—C3—H3	119.5
O5—Co1—N1ⁱ	84.97 (5)	C4—C3—H3	119.5
O4ⁱ—Co1—N1ⁱ	94.77 (5)	C5—C4—C3	121.56 (18)
O4—Co1—N1ⁱ	85.23 (5)	C5—C4—H4	119.2
O5ⁱ—Co1—N1	84.97 (5)	C3—C4—H4	119.2
O5—Co1—N1	95.03 (5)	C6—C5—C4	117.63 (17)
O4ⁱ—Co1—N1	85.23 (5)	C6—C5—H5	121.2
O4—Co1—N1	94.77 (5)	C4—C5—H5	121.2
O2—S1—O1	115.14 (8)	C1—C6—C5	120.11 (16)
O2—S1—N1	111.29 (8)	C1—C6—C7	111.46 (14)
O1—S1—N1	110.87 (8)	C5—C6—C7	128.36 (16)
O2—S1—C1	110.64 (8)	O3—C7—N1	124.77 (15)
O1—S1—C1	110.29 (8)	O3—C7—C6	122.14 (15)
N1—S1—C1	97.19 (8)	N1—C7—C6	113.08 (14)
O4—S2—C8	104.73 (8)	S2—C8—H8A	109.5
O4—S2—C9	105.08 (8)	S2—C8—H8B	109.5
C8—S2—C9	98.91 (10)	H8A—C8—H8B	109.5
S2—O4—Co1	125.54 (7)	S2—C8—H8C	109.5
Co1—O5—H5A	108.2 (18)	H8A—C8—H8C	109.5
Co1—O5—H5B	125.2 (16)	H8B—C8—H8C	109.5
H5A—O5—H5B	108 (2)	S2—C9—H9A	109.5
C7—N1—S1	110.58 (11)	S2—C9—H9B	109.5
C7—N1—Co1	121.08 (11)	H9A—C9—H9B	109.5
S1—N1—Co1	125.03 (8)	S2—C9—H9C	109.5
C2—C1—C6	122.81 (16)	H9A—C9—H9C	109.5
C2—C1—S1	130.12 (14)	H9B—C9—H9C	109.5
C6—C1—S1	107.07 (12)

Symmetry code: (i) −x+1, −y+1, −z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5A···O3ⁱ	0.98	1.73	2.646 (2)	155 (3)
O5—H5B···O1	0.98	2.09	2.803 (2)	128 (2)
O5—H5B···O1ⁱⁱ	0.98	2.06	2.904 (2)	143 (2)
C8—H8B···O5ⁱⁱⁱ	0.98	2.54	3.277 (2)	132
C8—H8B···O4^iv	0.98	2.51	3.383 (2)	148
C9—H9A···O3ⁱ	0.98	2.58	3.363 (2)	137
C9—H9B···O4^iv	0.98	2.58	3.432 (2)	146

Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x+1, −y+1, −z+1; (iii) −x+1, y+1/2, −z+1/2; (iv) x, −y+3/2, z+1/2.

Experimental details

Crystal data
Chemical formula	[Co(C₇H₄NO₃S)₂(C₂H₆OS)₂(H₂O)₂]
M_r	615.56
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	173
a, b, c (Å)	10.2304 (3), 15.1418 (6), 7.8615 (3)
β (°)	98.068 (2)
V (Å³)	1205.75 (8)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	1.12
Crystal size (mm)	0.27 × 0.15 × 0.10

Data collection
Diffractometer	Nonius KappaCCD
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.753, 0.897
No. of measured, independent and observed [I > 2σ(I)] reflections	5888, 3000, 2301
R_int	0.018
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.030, 0.081, 1.06
No. of reflections	3000
No. of parameters	171
No. of restraints	2
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.71, −0.49

Computer programs: COLLECT (Nonius, 1998), DENZO-SMN (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5A···O3ⁱ	0.98	1.73	2.646 (2)	155 (3)
O5—H5B···O1	0.98	2.09	2.803 (2)	127.9 (19)
O5—H5B···O1ⁱⁱ	0.98	2.06	2.904 (2)	143 (2)
C8—H8B···O5ⁱⁱⁱ	0.98	2.54	3.277 (2)	132.00
C8—H8B···O4^iv	0.98	2.51	3.383 (2)	148.00
C9—H9A···O3ⁱ	0.98	2.58	3.363 (2)	137.00
C9—H9B···O4^iv	0.98	2.58	3.432 (2)	146.00

Symmetry codes: (i) −x+1, −y+1, −z; (ii) −x+1, −y+1, −z+1; (iii) −x+1, y+1/2, −z+1/2; (iv) x, −y+3/2, z+1/2.

Acknowledgements

WEvZ gratefully acknowledges financial support from the University of KwaZulu-Natal. FSWP thanks the National Research Foundation (NRF) for an Innovative Grant.

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