Facial π...Cl...π inter­actions as the directing motif of the supra­molecular structures of Mg²⁺ and Ca²⁺ bis[hydro­tris(pyrazol­yl)­borate] chloro­form disolvates

The isomorphous complexes bis­[hydro­tris(pyrazol­yl)­borato]­mag­nesium(II) chloro­form disolvate, [Mg(C₉H₁₀BN₆)₂]·2CHCl₃, and bis­[hydro­tris(pyrazol­yl)borato]calcium(II) chloro­form disolvate, [Ca(C₉H₁₀BN₆)₂]·2CHCl₃, crystallize in the cubic space group Pa with Z = 4. The metal atoms occupy sites of symmetry, and their coordination is very similar to that found for the unsolvated Mg[HB(Pz)₃]₂ and Ca[HB(Pz)₃]₂ complexes (Pz is pyrazole). The inclusion of chloro­form mol­ecules on threefold rotation axes not only leads to high-symmetry crystal structures but also plays an important role in stabilizing the three-dimensional supramolecular architecture through facial Pz...Cl...Pz inter­actions.

S1. Comment

The coordination chemistry of the tris(pyrazolyl)borate ligand (Tp) has been extensively studied since its introduction in 1966 (Trofimenko, 1966). Tp forms a great variety of complexes with most metals and metalloids in a tridentate fashion. Trofimenko (1999) has termed this ligand and its derivatives `scorpionates', since the two equatorial pyrazole (Pz) rings look like the claws and the pseudoaxial pyrazole ring looks like the stinger of a scorpion. In this paper, we report the structures of the Mg²⁺, (I), and Ca²⁺, (II), bis[hydrotris(pyrazolyl)borate] chloroform disolvates.

The molecular structures of (I) and (II) are shown in Figs. 1(a) and 2(a), and selected bond lengths and angles are listed in Tables 1 and 2, respectively. In each complex the metal occupies a site of 3 symmetry and both Tp ligands are symmetrically tridentate; the geometry about the metal is trigonally distorted octahedral, with M—N bond lengths of 2.173 (3) Å in (I) and 2.4241 (18) Å in (II). The corresponding intraligand N—M—N bond angles are 84.94 (10) and 79.45 (6)°. The N···N distances, which correlate with the bite angles of the ligand, are 2.934 (2) and 3.098 (2) Å, respectively, and are governed by the relative ionic radii of the Mg²⁺ (0.65 Å) and Ca²⁺ (0.99 Å) ions (Huheey et al., 1993).

The coordination geometry in (I) and (II) is very similar to that seen in the corresponding unsolvated [HB(Pz)₃]₂Mg and [HB(Pz)₃]₂Ca complexes (Sohrin et al., 1994). The former crystallizes in the triclinic space group P1, with two crystallographically independent molecules lying across different inversion centres, whereas the latter crystallizes in the monoclinic space group C2/c, with two crystallographically independent molecules on twofold rotation axes. In contrast, the chloroform solvates (I) and (II) exhibit high symmetry and crystallize in the cubic space group Pa3, with the metals on sites of 3 symmetry and the chloroform molecules on threefold rotation axes. The influence of CHCl₃ on the regulation of crystal structure has been documented by comparing the structures of the chloroform solvate (monoclinic, space group P2₁/c; Nielson et al., 2003) and the toluene solvate (triclinic, space group P1; Davidson et al., 2003) of the zwitterion bis[tris(3,5-dimethyl-2-oxidobenzyl-κO)ammonium]zirconium(IV), and those of trans-bis(2,2-diphenylethylamine-κN)bis(5,5-diphenylhydantoinato-κN³)copper(II) and its chloroform solvate (triclinic, space group P1, and orthorhombic, space group Pbca, respectively; Akitsu & Binaga, 2005). In both cases, chloroform influences crystallization to give structures that are more symmetric than those observed for unsolvated complexes or those solvated by other solvents.

##AUTHOR: The following has been re-written so please check carefully: Chloroform molecules play an important role in the development of the supramolecular architecture of (I) and (II), its inclusion is governed by electrophile–nuclephile C—Cl···π interactions (Csöregh et al., 1996) to form a three-dimensional network. Each Cl atom of the chloroform solvent interacts with two pyrazole rings in the same neighbouring molecule. In (I) (Fig. 3), the relevant parameters are C6—Cl1···Pz^vi = 3.5018 (16) Å, C6—Cl1···Pz^vi = 91.14 (14)°, C6—Cl1···Pz^vii = 3.4906 (16) Å, C6—Cl1···Pz^vii = 165.05 (15)°, Cl···Pz···Cl = 158.4 (2)° and Pz···Cl···Pz = 75.7 (2)° [Pz is the centroid of the pyrazole ring; symmetry codes: (vi) z, −x + 1/2, y − 1/2; (vii) y, −z + 1/2, x − 1/2.] The corresponding values for (II) are 3.5148 (12) Å, 94.06 (8)°, 3.5443 (12) Å, 170.79 (9)°, 163.0 (2)° and 76.8 (2)°. Each chloroform molecule is therefore linked to three molecules of the metal complex, generating the three-dimensional network structure.

Interaction lengths and angles are in the mean range for this electrophile–nucleophile π···X···π motif (Csöregh et al., 1996), as well as for C—Cl···π database studies carried out on organic crystal structures (Prasanna & Row, 2000) and in proteins (Saraogi et al., 2003). The experimental data typical of Cl···π-facial interactions (Galan-Mascaros et al., 1996), which have been found in both chloride (Demeshko et al., 2004) and C—Cl (Aravindan et al., 2003) interactions with π-deficient heterocycles.

In summary, chloroform inclusion in Mg[(HB(Pz)₃)₂] and Ca[(HB(Pz)₃)₂] complexes not only leads to highly symmetric structures, in contrast to the unsolvated complexes, but also plays an important role in stabilizing the supramolecular architecture through Pz···Cl···Pz interactions.

S2. Experimental

For (I), an ethanol solution (15 ml) of K[HB(Pz)₃] (0.100 g, 0.396 mmol) was added to an ethanol solution (15 ml) of anhydrous MgCl₂ (0.019 g, 0.198 mmol). The resulting solution was stirred for 30 min. The solution was filtered, and the filtrate was evaporated to dryness under N₂ atmosphere to give a white powder (0.091 g, 87% yield). Recrystallization from dry chloroform afforded colourless blocks suitable for X-ray analysis. ¹H NMR (CDCl₃, p.p.m.): δ 6.06 (t, 6H, ³J = 2.0 Hz, H-4), 7.15, 7.70 (d, d, 6H each, ³J = 1.8 Hz, H-3,5). Complex (II) was prepared and recrystallized as for (I), using K[HB(Pz)₃] (0.100 g, 0.396 mmol) and anhydrous CaCl₂ (0.022 g, 0.198 mmol), to give a white powder (0.099 g, 92% yield). ¹H NMR (CDCl₃, p.p.m.): δ 6.15 (t, 6H, ³J = 1.9 Hz, H-4), 7.51, 7.75 (d, d, 6H each, ³J = 1.8 and 2.2 Hz, H-3,5).

S3. Refinement

All H atoms were refined as riding on their parent atoms, with B—H and C—H distances using in the range 0.98 Å to 0.93 Å, and with U_iso(H) = 1.5U_eq(B) for B—H and 1.2U_eq(C) for C—H.

Computing details

For both compounds, data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Mercury 1.4 (Bruno et al., 2002); software used to prepare material for publication: SHELXL97 and WinGX2003 (Farrugia, 1999).

Figures

	Fig. 1. (a) The molecular structure of (I), showing displacement ellipsoids drawn at the 30% probability level [symmetry codes: (i) z, x, y; (ii) y, z, x; (iii) −z + 1, −x + 1, −y + 1; (iv) −y + 1, −z + 1, −x + 1; (v) −x + 1, −y + 1, −z + 1]; (b) top view.
	Fig. 2. (a) The molecular structure of (II), showing displacement ellipsoids drawn at the 30% probability level [symmetry codes: (i) z, x, y; (ii) y, z, x; (iii) −z + 1, −x + 1, −y + 1; (iv) −y + 1, −z + 1, −x + 1; (v) −x + 1, −y + 1, −z + 1]; (b) top view.
	Fig. 3. The three-dimensional network structure of (I) is built up through π···Cl···π interactions. [Symmetry codes: (vi) z, −x + 1/2, y − 1/2; (vii) y, −z + 1/2, x − 1/2.] Compounds (I) and (II) are isostructural.

(I) bis[hydrotris(pyrazolyl)borato]magnesium(II) chloroform disolvate

Crystal data

[Mg(C9H10BN6)2]·2CHCl3	Dx = 1.550 Mg m^−3
Mr = 689.13	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pa3	Cell parameters from 600 reflections
Hall symbol: -P 2ac 2ab 3	θ = 20–25°
a = 14.3475 (12) Å	µ = 0.64 mm^−1
V = 2953.4 (4) Å^3	T = 100 K
Z = 4	Block, colorless
F(000) = 1400	0.20 × 0.12 × 0.09 mm

Data collection

Bruker SMART CCD area-detector diffractometer	944 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.055
ϕ and ω scans	θmax = 26.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −17→14
Tmin = 0.883, Tmax = 0.945	k = −17→17
15868 measured reflections	l = −11→17
969 independent reflections

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)] = 0.060	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.124	H-atom parameters constrained
S = 1.22	w = 1/[σ^2(Fo^2) + (0.0339P)^2 + 10.6109P] where P = (Fo^2 + 2Fc^2)/3
969 reflections	(Δ/σ)max < 0.001
63 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.36 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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 (Ų)

	x	y	z	Uiso*/Ueq
Mg	0.50000	0.50000	0.50000	0.0091 (3)
N1	0.49046 (18)	0.49637 (19)	0.34889 (19)	0.0120 (8)
N2	0.43289 (18)	0.43260 (18)	0.30933 (18)	0.0091 (7)
C3	0.4397 (2)	0.4362 (2)	0.2163 (2)	0.0137 (9)
C4	0.5035 (2)	0.5043 (3)	0.1935 (2)	0.0163 (10)
C5	0.5332 (2)	0.5398 (2)	0.2789 (2)	0.0151 (9)
B1	0.3696 (2)	0.3696 (2)	0.3696 (2)	0.0113 (7)
Cl1	0.28234 (6)	0.22160 (6)	0.11889 (6)	0.0224 (3)
C6	0.1855 (3)	0.1855 (3)	0.1855 (3)	0.0170 (7)
H1	0.33018	0.33018	0.33018	0.0135*
H3	0.40693	0.39921	0.17437	0.0164*
H4	0.52249	0.52243	0.13423	0.0195*
H5	0.57681	0.58726	0.28595	0.0181*
H6	0.14604	0.14604	0.14604	0.0204*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mg	0.0091 (5)	0.0091 (5)	0.0091 (5)	−0.0005 (6)	−0.0005 (6)	−0.0005 (6)
N1	0.0093 (13)	0.0129 (13)	0.0138 (13)	−0.0009 (10)	−0.0010 (11)	−0.0009 (11)
N2	0.0099 (13)	0.0085 (12)	0.0090 (13)	0.0003 (10)	−0.0018 (10)	−0.0020 (10)
C3	0.0162 (16)	0.0154 (16)	0.0094 (15)	0.0020 (13)	−0.0007 (13)	−0.0020 (12)
C4	0.0187 (17)	0.0183 (17)	0.0118 (16)	−0.0010 (14)	0.0026 (13)	0.0031 (13)
C5	0.0118 (16)	0.0136 (16)	0.0198 (17)	−0.0022 (13)	0.0013 (13)	0.0017 (13)
B1	0.0113 (12)	0.0113 (12)	0.0113 (12)	−0.0039 (13)	−0.0039 (13)	−0.0039 (13)
Cl1	0.0248 (5)	0.0210 (5)	0.0213 (5)	0.0009 (3)	0.0087 (3)	0.0009 (3)
C6	0.0170 (12)	0.0170 (12)	0.0170 (12)	0.0001 (14)	0.0001 (14)	0.0001 (14)

Geometric parameters (Å, º)

Mg—N1	2.173 (3)	C3—H3	0.9300
N1—C5	1.331 (4)	C4—H4	0.9300
N1—N2	1.357 (4)	C5—H5	0.9300
N2—C3	1.339 (4)	C6—H6	0.9800
N2—B1	1.546 (4)	B1—H1	0.9800
C3—C4	1.378 (5)	Cl1—C6	1.764 (4)
C4—C5	1.394 (4)
Cl1···N2^i	3.459 (3)	N2···Cl1^x	3.494 (3)
Cl1···N2^ii	3.494 (3)	C3···Cl1^x	3.623 (3)
Cl1···C3^ii	3.623 (3)	C3···Cl1^ix	3.504 (3)
Cl1···C3^i	3.504 (3)	C3···H4^iii	3.0400
Cl1···H5^iii	3.0900	C4···H6^xi	3.0300
Cl1···H5^iv	3.1100	C4···H6^xii	3.0300
N1···N1^v	3.206 (4)	C4···H6^x	3.0300
N1···N1^vi	2.934 (4)	H3···H4^iii	2.5200
N1···N2^vi	3.004 (4)	H4···C3^xiii	3.0400
N1···N1^vii	2.934 (4)	H4···H3^xiii	2.5200
N1···N2^vii	3.057 (4)	H5···Cl1^xiii	3.0900
N1···N1^viii	3.206 (4)	H5···Cl1^xiv	3.1100
N2···N1^vii	3.004 (4)	H6···C4^xv	3.0300
N2···Cl1^ix	3.459 (3)	H6···C4^ii	3.0300
N2···N1^vi	3.057 (4)	H6···C4^xvi	3.0300
N1—Mg—N1^vi	84.94 (10)	N2—C3—H3	126.00
Mg—N1—N2	118.15 (19)	C4—C3—H3	126.00
Mg—N1—C5	135.4 (2)	C3—C4—H4	128.00
N2—N1—C5	106.3 (2)	C5—C4—H4	128.00
N1—N2—C3	110.3 (2)	C4—C5—H5	125.00
N1—N2—B1	121.2 (2)	N1—C5—H5	125.00
C3—N2—B1	128.5 (2)	N2—B1—N2^vii	108.2 (2)
N2—C3—C4	108.2 (3)	N2—B1—H1	111.00
C3—C4—C5	104.7 (3)	Cl1—C6—Cl1^vi	110.8 (2)
N1—C5—C4	110.6 (3)	Cl1—C6—H6	108.00
N1^vi—Mg—N1—N2	−45.3 (2)	C5—N1—N2—B1	−178.7 (2)
N1^vii—Mg—N1—N2	40.1 (2)	Mg—N1—C5—C4	175.4 (2)
N1^viii—Mg—N1—N2	134.7 (2)	N2—N1—C5—C4	0.0 (4)
N1^v—Mg—N1—N2	−139.9 (2)	N1—N2—C3—C4	−0.1 (3)
N1^vi—Mg—N1—C5	139.8 (3)	N1—N2—B1—N2^vi	55.4 (3)
N1^vii—Mg—N1—C5	−134.9 (3)	B1—N2—C3—C4	178.6 (3)
N1^viii—Mg—N1—C5	−40.2 (3)	C3—N2—B1—N2^vii	119.9 (3)
N1^v—Mg—N1—C5	45.1 (3)	C3—N2—B1—N2^vi	−123.2 (3)
Mg—N1—N2—C3	−176.28 (19)	N1—N2—B1—N2^vii	−61.6 (3)
Mg—N1—N2—B1	5.0 (3)	N2—C3—C4—C5	0.0 (4)
C5—N1—N2—C3	0.0 (3)	C3—C4—C5—N1	0.0 (4)

Symmetry codes: (i) y, −z+1/2, x−1/2; (ii) z, −x+1/2, y−1/2; (iii) −z+1/2, −x+1, y−1/2; (iv) −x+1, y−1/2, −z+1/2; (v) −y+1, −z+1, −x+1; (vi) z, x, y; (vii) y, z, x; (viii) −z+1, −x+1, −y+1; (ix) z+1/2, x, −y+1/2; (x) −y+1/2, z+1/2, x; (xi) −x+1/2, y+1/2, z; (xii) −z+1/2, x+1/2, y; (xiii) −y+1, z+1/2, −x+1/2; (xiv) −x+1, y+1/2, −z+1/2; (xv) −x+1/2, y−1/2, z; (xvi) y−1/2, z, −x+1/2.

(II) bis[hydrotris(pyrazolyl)borato]calcium(II) chloroform disolvate

Crystal data

[Ca(C9H10BN6)2]·2CHCl3	Dx = 1.483 Mg m^−3
Mr = 704.90	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pa3	Cell parameters from 600 reflections
Hall symbol: -P 2ac 2ab 3	θ = 20–25°
a = 14.6697 (9) Å	µ = 0.74 mm^−1
V = 3156.9 (3) Å^3	T = 100 K
Z = 4	Block, colorless
F(000) = 1432	0.3 × 0.2 × 0.2 mm

Data collection

Bruker SMART CCD area-detector diffractometer	1272 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
ϕ and ω scans	θmax = 28.3°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −18→18
Tmin = 0.808, Tmax = 0.866	k = −18→12
17681 measured reflections	l = −19→18
1293 independent reflections

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.109	H-atom parameters constrained
S = 1.31	w = 1/[σ^2(Fo^2) + (0.0316P)^2 + 4.1829P] where P = (Fo^2 + 2Fc^2)/3
1293 reflections	(Δ/σ)max < 0.001
63 parameters	Δρmax = 0.44 e Å^−3
0 restraints	Δρmin = −0.40 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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 (Ų)

	x	y	z	Uiso*/Ueq
Ca	0.50000	0.50000	0.50000	0.0141 (1)
N1	0.48740 (12)	0.48337 (13)	0.33608 (12)	0.0192 (5)
N2	0.42579 (11)	0.42280 (11)	0.30197 (11)	0.0148 (5)
C3	0.42747 (16)	0.42495 (15)	0.21011 (14)	0.0207 (6)
C4	0.49139 (16)	0.48835 (16)	0.18296 (15)	0.0245 (7)
C5	0.52681 (15)	0.52263 (16)	0.26431 (15)	0.0225 (6)
B1	0.36350 (15)	0.36350 (15)	0.36350 (15)	0.0146 (4)
Cl1	0.28142 (5)	0.21172 (5)	0.12085 (5)	0.0376 (2)
C6	0.18308 (16)	0.18308 (16)	0.18308 (16)	0.0237 (5)
H1	0.32493	0.32493	0.32493	0.0175*
H3	0.39159	0.38966	0.17156	0.0248*
H4	0.50730	0.50458	0.12378	0.0294*
H5	0.57195	0.56700	0.26794	0.0270*
H6	0.14451	0.14451	0.14451	0.0284*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ca	0.0141 (2)	0.0141 (2)	0.0141 (2)	−0.0023 (2)	−0.0023 (2)	−0.0023 (2)
N1	0.0184 (9)	0.0214 (9)	0.0177 (9)	−0.0059 (7)	−0.0014 (7)	0.0005 (7)
N2	0.0151 (8)	0.0167 (8)	0.0125 (8)	−0.0001 (6)	−0.0001 (6)	−0.0002 (6)
C3	0.0241 (11)	0.0239 (10)	0.0141 (9)	−0.0014 (9)	−0.0011 (8)	−0.0022 (8)
C4	0.0287 (12)	0.0282 (12)	0.0167 (10)	−0.0036 (9)	0.0038 (9)	0.0027 (9)
C5	0.0215 (10)	0.0255 (11)	0.0205 (10)	−0.0057 (9)	0.0022 (8)	0.0030 (8)
B1	0.0146 (7)	0.0146 (7)	0.0146 (7)	−0.0013 (8)	−0.0013 (8)	−0.0013 (8)
Cl1	0.0416 (4)	0.0370 (4)	0.0341 (3)	−0.0098 (3)	0.0157 (3)	−0.0097 (3)
C6	0.0237 (8)	0.0237 (8)	0.0237 (8)	−0.0017 (9)	−0.0017 (9)	−0.0017 (9)

Geometric parameters (Å, º)

Ca—N1	2.4241 (18)	C3—H3	0.9300
N1—C5	1.332 (3)	C4—H4	0.9300
N1—N2	1.363 (2)	C5—H5	0.9300
N2—C3	1.348 (3)	C6—H6	0.9800
N2—B1	1.551 (3)	B1—H1	0.9800
C3—C4	1.380 (3)	Cl1—C6	1.758 (2)
C4—C5	1.395 (3)
N1···N1^i	3.098 (3)	C4···H6^v	3.0900
N1···N2^i	3.120 (2)	C4···H4^vi	3.0600
N1···N1^ii	3.098 (3)	H4···C4^vii	3.0600
N1···N2^ii	3.116 (2)	H4···H4^vii	2.5400
N2···N1^i	3.116 (2)	H4···H4^vi	2.5400
N2···N1^ii	3.120 (2)	H6···C4^viii	3.0900
C4···H6^iii	3.0900	H6···C4^ix	3.0900
C4···H6^iv	3.0900	H6···C4^x	3.0900
N1—Ca—N1^i	79.45 (6)	N2—C3—H3	126.00
Ca—N1—N2	118.72 (12)	C4—C3—H3	126.00
Ca—N1—C5	135.03 (15)	C3—C4—H4	128.00
N2—N1—C5	106.23 (17)	C5—C4—H4	128.00
N1—N2—C3	109.86 (17)	C4—C5—H5	124.00
N1—N2—B1	122.87 (16)	N1—C5—H5	124.00
C3—N2—B1	127.26 (17)	N2—B1—N2^ii	109.80 (16)
N2—C3—C4	108.47 (19)	N2—B1—H1	109.00
C3—C4—C5	104.43 (19)	Cl1—C6—Cl1^i	110.74 (13)
N1—C5—C4	111.0 (2)	Cl1—C6—H6	108.00
N1^i—Ca—N1—N2	−40.39 (14)	C5—N1—N2—B1	−178.87 (18)
N1^ii—Ca—N1—N2	40.70 (14)	Ca—N1—C5—C4	−178.12 (16)
N1^xi—Ca—N1—N2	139.61 (14)	N2—N1—C5—C4	0.1 (2)
N1^xii—Ca—N1—N2	−139.30 (14)	N1—N2—C3—C4	−0.1 (2)
N1^i—Ca—N1—C5	137.7 (2)	N1—N2—B1—N2^i	60.6 (2)
N1^ii—Ca—N1—C5	−141.3 (2)	B1—N2—C3—C4	178.71 (19)
N1^xi—Ca—N1—C5	−42.4 (2)	C3—N2—B1—N2^ii	121.1 (2)
N1^xii—Ca—N1—C5	38.8 (2)	C3—N2—B1—N2^i	−118.1 (2)
Ca—N1—N2—C3	178.57 (14)	N1—N2—B1—N2^ii	−60.2 (2)
Ca—N1—N2—B1	−0.3 (2)	N2—C3—C4—C5	0.2 (3)
C5—N1—N2—C3	0.0 (2)	C3—C4—C5—N1	−0.2 (3)

Symmetry codes: (i) z, x, y; (ii) y, z, x; (iii) −x+1/2, y+1/2, z; (iv) −z+1/2, x+1/2, y; (v) −y+1/2, z+1/2, x; (vi) y, −z+1/2, x−1/2; (vii) z+1/2, x, −y+1/2; (viii) −x+1/2, y−1/2, z; (ix) z, −x+1/2, y−1/2; (x) y−1/2, z, −x+1/2; (xi) −z+1, −x+1, −y+1; (xii) −y+1, −z+1, −x+1.