Crystal structure of cis-1-phenyl-8-(pyridin-2-ylmeth­yl)dibenzo[1,2-c:2,1-h]-2,14-dioxa-8-aza-1-borabi­cyclo­[4.4.0]deca-3,8-diene

Ledesma, G.; Signorella, S.; Back, D.; Schulz Lang, E.

doi:10.1107/S2056989017016553

research communications

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ISSN: 2056-9890

Volume 73| Part 12| December 2017| Pages 1917-1920

https://doi.org/10.1107/S2056989017016553

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Crystal structure of cis-1-phenyl-8-(pyridin-2-ylmethyl)dibenzo[1,2-c:2,1-h]-2,14-dioxa-8-aza-1-borabicyclo[4.4.0]deca-3,8-diene

Gabriela Ledesma,^a ^* Sandra Signorella,^a Davi Back ^b and Ernesto Schulz Lang ^b

^aIQUIR (Instituto de Química Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, (S2002LRK), Rosario, Argentina, and ^bLaboratório de Materiais Inorgânicos, Department of Chemistry, Federal University of Santa Maria, UFSM, 97115-900 Santa Maria, RS, Brazil
^*Correspondence e-mail: ledesma@iquir-conicet.gov.ar

Edited by C. Rizzoli, Universita degli Studi di Parma, Italy (Received 28 October 2017; accepted 16 November 2017; online 21 November 2017)

The title compound, C₂₆H₂₃BN₂O₂, was obtained as by product during synthetic attempts of a complexation reaction between the tripodal ligand H₂L [N,N-bis(2-hydroxybenzyl)(pyridin-2-yl)methylamine] and manganese(III) acetate in the presence of NaBPh₄. The isolated B-phenyl dioxazaborocine contains an N→B dative bond with a cis conformation. In the crystal, C—H⋯O hydrogen bonds define chains parallel to the b-axis direction. A comparative analysis with other structurally related derivatives is also included, together with a rationalization of the unexpected production of this zwitterionic heterocycle.

Keywords: crystal structure; B-phenyldioxazaborocine; N—B dative bond; zwitterionic heterocycle; C—H⋯O interactions.

CCDC reference: 1586032

1. Chemical context

As part of our research program directed at obtaining manganese complexes as bio-inspired mimetics with different nuclearity and properties (Ledesma et al., 2014 , 2015 ), we were interested in coordination reactions of the tripodal tetradentate ligand H₂L, namely N,N-bis(2-hydroxybenzyl)(pyrid-2-yl)methylamine. We envisaged a systematic study comprising the use of several metal-to-ligand ratios, with the idea of varying the nuclearity of the resulting compounds. Unexpectedly, however, during consecutive attempts to obtain manganese complexes derived from H₂L, we isolated the B-phenyl dioxazaborocine derivative, I. Here we report its synthesis and crystal structure and, in order to unravel its presence, we rationalize its production under the employed reaction conditions. A comparative analysis of its structural data with that of other dioxazaborocines is also presented.

2. Structural commentary

The title compound I, Fig. 1, which represents one of the few examples of B-phenyl dioxazaborocine derivatives reported in the literature, crystallizes in the triclinic space group P $[\overline{1}]$ with two molecules in the unit cell. The boron atom shows a distorted tetrahedral coordination sphere described by one N atom (N1), two oxygen atoms (O1, O2) and one carbon atom from a phenyl ring (C15). The geometry about the intramolecular N1—B1 bond is cis, as inferred from the spatial arrangement of atoms C15–B1–N1–C21. The B—O bond lengths are 1.446 (3) and 1.471 (3) Å and the B—N bond length is 1.674 (4) Å. The BNC₃O six-membered rings adopt a half-chair conformation, with puckering parameters Q_T = 0.502 (2) Å, θ₂ = 135.4 (2)°, φ₂ = −138.4 (4)° for B1/N1/C7/C6/C1/O1, and Q_T = 0.525 (2) Å, θ₂ = 132.2 (3)°, φ₂ = −144.8 (4)° for B1/N1/C14/C13/C8/O2.

Figure 1
The molecular structure of the title molecule, with displacement ellipsoids drawn at the 50% probability level. Hydrogen atoms are omitted for clarity.

3. Supramolecular features

The crystal packing in I is defined by two sets of C—H⋯O hydrogen bonds. The first group implicates C2—H2⋯O1ⁱ atoms, giving rise to a dimeric system with a C—H⋯O angles of 167.5° (Fig. 2, Table 1). The remaining interaction, C24—H24⋯O2ⁱⁱ, shows a small C—H⋯O angle of 129.4°, indicating that this C—H⋯O hydrogen bond is quite weak. The two interactions link molecules into chains parallel to the b axis (Fig. 3), consolidating the three-dimensional molecular packing.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯O1ⁱ	0.95	2.57	3.503 (3)	168
C24—H24⋯O2ⁱⁱ	0.95	2.50	3.185 (3)	129
Symmetry codes: (i) -x+1, -y+2, -z+2; (ii) x, y-1, z.

Figure 2
Detail of the intermolecular interactions in the title compound forming a dimeric system through C—H⋯O hydrogen bonds (dashed lines). H atoms not involved in these hydrogen bonds are omitted [symmetry code: (i)= 1 − x, 2 − y, 2 − z].

Figure 3
Detail of C—H⋯O interactions in the title compound (grey and orange dashed lines denote C2—H2⋯O1ⁱ and C24—H24⋯O2ⁱⁱ interactions, respectively). H atoms not involved in these interactions are omitted for clarity [symmetry codes: (i) 1 − x, 2 − y, 2 − z; (ii) x, −1 + y, z].

4. Database survey

A survey of the Cambridge Structural Database (CSD Version 5.38; Groom et al., 2016 ) showed a few reported examples of dioxazaborocines (Geng & Wu, 2011 ; Gawdzik et al., 2009 ; Zhu et al., 2006 ; Thadani et al., 2001 ; Woodgate et al., 2000 ; Woodgate et al., 1999 ). Specifically, two members of this selected group are structurally related to the title compound: II (MAWDET; Woodgate et al., 1999) and the recently described compound III (EROJIF; Geng & Wu, 2011) (Fig. 4).

Figure 4
Oxazaborocine compounds structurally related to the title compound.

Table 2 summarizes relevant bond lengths and angles for I compared with those observed in II and III. The intramolecular N—B bond lengths can vary, depending on the substituent groups to boron and nitrogen atoms. In particular, the covalent N1—B1 bond distance for I [1.674 (4) Å] is in the range observed for III and II [1.641 (2)–1.674 (5) Å]. The N—B bond distance for III is shorter than that in II, quite probably due to the extra oxygen atom bonded to the boron atom (from the –OCH₃ group).

Table 2
Structural data and calculated tetrahedral character THC_DA (Å, °) for compounds I–III

	Compound I	II (MAWDET)^a	III (EROJIF)^b
Bond lengths
B—N	1.674 (4) (B1—N1)	1.674 (5) (B1—N1)	1.641 (2) (B1—N2)
B—O	1.471 (3) (B1—O2)	1.443 (4) (B1—O2)	1.443 (2) (B1—O3)
B—O	1.446 (3) (B1—O1)	1.454 (4) (B1—O1)	1.463 (2) (B1—O5)
B—C	1.602 (4) (B1—C15)	1.608 (5) (B1—C15)	1.425 (2) (B1—O4)
Angles
θ₁	113.0 (2) (C15—B1—O2)	110.3 (3) (C15—B—O2)	113.34 (15) (O4—B1—O3)
θ₂	109.5 (2) (C15—B1—O1)	115.5 (3) (C15—B—O1)	114.47 (16) (O4—B1—O5)
θ₃	109.0 (2) (O2—B1—O1)	109.5 (3) (O2—B—O1)	108.60 (15) (O3—B1—O5)
θ₄	113.5 (2) (N1—B1—C15)	110.0 (3) (N1—B—C15)	105.64 (14) (N2—B1—O4)
θ₅	104.5 (2) (N1—B1—O2)	106.7 (3) (N1—B—O2)	108.45 (14) (N2—B1—O3)
θ₆	107.1 (2) (N1—B1—O1)	104.4 (3) (N1—B—O1)	105.89 (13) (N2—B1—O5)
THC_DA^c	82.8	83.1	79.7
(a) Woodgate et al. (1999); (b) Geng et al. (2011); (c) Höpfl et al. (1999).

The crystal structure of I shows that the phenyl group at the boron atom and the N-pyridin-2-ylmethyl substituent adopts a cis conformation around the N→B dative bond, in total agreement with that reported for II and III. The C21—N1—B1—C15 torsion angle assumes a value of 57.8 (3)°. Analysis of the structural data for II showed the corresponding torsion angle (C37—N1—B1—C15) is 56.71°. In compound III, the corresponding angle (C13—N2—B1—O4) is 62.34°. These two examples display a cis geometry around the intramolecular N—B bond, in concordance with compound I (Fig. 5).

Figure 5
Comparison of the bonding environment at boron in I (title compound), II (MAWDET) and III (EROJIF). For clarity, only atoms closely involved in the N→B dative bonds are shown.

We have performed an analysis of the experimental data of compounds I--III and calculated the tetrahedral character (THC_DA) at the boron atom (Höpfl et al., 1999 ), making use of the values of the six angles around the boron atom (θ₁–θ₆). The quite high value of 82.8% for I is in the range observed for compounds II and III. Altogether, this parameter and the measured N—B bond lengths can be considered a clear indication of sp³-hybridization of the boron atom and of a resident negative charge (Sarina et al., 2015 ). Therefore, we confirm that compound I adopts a zwitterionic form with a significant intramolecular N→B dative bond.

Based on previous observations (Barnes et al., 1998 ), we hypothesize that employing an aqueous solution of NaBPh₄ led to the unexpected isolation of I. It is well known that NaBPh₄ in the presence of oxygen leads to the production of phenylboronic acid PhB(OH)₂ and phenol. Then, the in situ generated phenylboronic acid (derived in turn from an excess of NaBPh₄) is capable of reacting with the tripodal ligand H₂L, leading to the formation of compound I (Fig. 6).

Figure 6
Synthesis of the title compound.

Inspection of the reaction conditions already reported by Woodgate et al. (1999) indicates that compound II was obtained by reaction of phenylboronic acid and the corresponding tertiary amine. In turn, the authors reported that compound III was obtained unintentionally when using salicylaldehyde benzylamine and boron compounds (Geng et al., 2011). We hypothesize that, in the case of I, the use of NaBPh₄ determined the course of the reaction, leading to the formation of the zwitterionic heterocycle in the described reaction conditions.

5. Synthesis and crystallization

H₂L (0.064 g; 0.2 mmol) was dissolved in methanol (4 mL), then solid manganese(III) acetate dihydrate (0.052 g; 0.2 mmol) was added. Immediately after, an excess of NaBPh₄ (0.2065 g, 0.60 mmol) in 2 mL of methanol/water was added to the reaction flask. The resulting dark-brown solution was sonicated at 313 K for 15 min and then stirred at reflux for additional 16 h (overnight). After cooling, the obtained precipitate was collected by filtration, washed with diethyl ether and dried in vacuo. Recrystallization from methanol gave colourless crystals of I suitable for X-ray diffraction. Yield: 21%. IR spectrum: ν(cm⁻¹): 3043, 1630 (C=N), 1626, 1608 (C=C aromatic), 1462 (br, B—O), 1273, 1248, 1200, 1050 (C—O), 1002 (B—N), 702.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3. H atoms were placed at calculated positions, with d(C—H) = 0.95−0.99 Å and U_iso(H) = 1.2U_eq(C).

Table 3
Experimental details

Crystal data
Chemical formula	C₂₆H₂₃BN₂O₂
M_r	406.27
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	100
a, b, c (Å)	8.8803 (7), 10.0871 (8), 11.7586 (10)
α, β, γ (°)	97.298 (2), 98.464 (2), 98.234 (2)
V (Å³)	1019.21 (14)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.08
Crystal size (mm)	0.22 × 0.16 × 0.12

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Gaussian (XPREP and SADABS; Bruker, 2008 )
T_min, T_max	0.780, 0.875
No. of measured, independent and observed [I > 2σ(I)] reflections	8344, 4004, 2161
R_int	0.088
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.059, 0.115, 0.92
No. of reflections	4004
No. of parameters	280
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.31
Computer programs: APEX2 and SAINT (Bruker, 2008), SHELXS97 and SHELXTL (Sheldrick, 2008 ), SHELXL2016 (Sheldrick, 2015 ) and DIAMOND (Brandenburg, 2012 ).

Supporting information

CCDC reference: 1586032

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S2056989017016553/rz5224sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989017016553/rz5224Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989017016553/rz5224Isup3.cml

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg, 2012); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

cis-1-Phenyl-8-(pyridin-2-ylmethyl)dibenzo[1,2-c:2,1-h]-2,14-dioxa-8-aza-1-borabicyclo[4.4.0]deca-3,8-diene top

Crystal data top

C₂₆H₂₃BN₂O₂	Z = 2
M_r = 406.27	F(000) = 428
Triclinic, P1	D_x = 1.324 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.8803 (7) Å	Cell parameters from 5951 reflections
b = 10.0871 (8) Å	θ = 2.4–28.2°
c = 11.7586 (10) Å	µ = 0.08 mm⁻¹
α = 97.298 (2)°	T = 100 K
β = 98.464 (2)°	Prism, colourless
γ = 98.234 (2)°	0.22 × 0.16 × 0.12 mm
V = 1019.21 (14) Å³

Data collection top

Bruker APEXII CCD diffractometer	2161 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.088
φ and ω scans	θ_max = 26.0°, θ_min = 2.4°
Absorption correction: gaussian (XPREP and SADABS; Bruker, 2008)	h = −10→10
T_min = 0.780, T_max = 0.875	k = −12→10
8344 measured reflections	l = −14→14
4004 independent reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.115	H-atom parameters constrained
S = 0.92	w = 1/[σ²(F_o²) + (0.0336P)²] where P = (F_o² + 2F_c²)/3
4004 reflections	(Δ/σ)_max < 0.001
280 parameters	Δρ_max = 0.25 e Å⁻³
0 restraints	Δρ_min = −0.31 e Å⁻³

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
O2	0.33571 (19)	0.80339 (16)	0.66654 (14)	0.0162 (4)
C7	0.2240 (3)	0.5768 (2)	0.7698 (2)	0.0154 (6)
H7A	0.186984	0.481569	0.777707	0.018*
H7B	0.15142	0.602455	0.707238	0.018*
O1	0.45343 (19)	0.81457 (16)	0.86313 (14)	0.0155 (4)
N1	0.3811 (2)	0.58730 (19)	0.73635 (17)	0.0142 (5)
N2	0.3294 (3)	0.3306 (2)	0.87553 (18)	0.0228 (6)
C1	0.3311 (3)	0.7832 (2)	0.9193 (2)	0.0141 (6)
C15	0.6210 (3)	0.7798 (2)	0.7133 (2)	0.0145 (6)
C6	0.2247 (3)	0.6666 (2)	0.8822 (2)	0.0143 (6)
C8	0.2760 (3)	0.7354 (2)	0.5582 (2)	0.0149 (6)
C22	0.4325 (3)	0.3686 (2)	0.8075 (2)	0.0164 (6)
C20	0.6479 (3)	0.8046 (2)	0.6034 (2)	0.0168 (6)
H20	0.562356	0.799166	0.543102	0.02*
C14	0.3653 (3)	0.5215 (2)	0.6124 (2)	0.0159 (6)
H14A	0.469245	0.515167	0.593371	0.019*
H14B	0.307445	0.428216	0.603349	0.019*
C13	0.2833 (3)	0.5988 (2)	0.5288 (2)	0.0154 (6)
C2	0.3191 (3)	0.8716 (3)	1.0178 (2)	0.0184 (6)
H2	0.391788	0.952737	1.042134	0.022*
C19	0.7968 (3)	0.8371 (3)	0.5794 (2)	0.0218 (7)
H19	0.811445	0.851654	0.503233	0.026*
C3	0.2016 (3)	0.8410 (3)	1.0797 (2)	0.0209 (7)
H3	0.192493	0.901899	1.145982	0.025*
C26	0.4860 (3)	0.2759 (2)	0.7329 (2)	0.0183 (6)
H26	0.56079	0.305733	0.687579	0.022*
C5	0.1087 (3)	0.6353 (3)	0.9472 (2)	0.0195 (6)
H5	0.036794	0.553633	0.923746	0.023*
C9	0.2030 (3)	0.8050 (3)	0.4773 (2)	0.0190 (7)
H9	0.198548	0.898346	0.497886	0.023*
C16	0.7521 (3)	0.7913 (2)	0.7980 (2)	0.0197 (7)
H16	0.738836	0.77471	0.873908	0.024*
C12	0.2147 (3)	0.5337 (3)	0.4180 (2)	0.0183 (6)
H12	0.216587	0.439785	0.397566	0.022*
C4	0.0970 (3)	0.7221 (3)	1.0458 (2)	0.0226 (7)
H4	0.017669	0.699995	1.089651	0.027*
C25	0.4296 (3)	0.1387 (3)	0.7247 (2)	0.0222 (7)
H25	0.464256	0.073442	0.673508	0.027*
C17	0.9002 (3)	0.8257 (3)	0.7761 (2)	0.0217 (7)
H17	0.986288	0.834068	0.836496	0.026*
C10	0.1376 (3)	0.7395 (3)	0.3682 (2)	0.0223 (7)
H10	0.087663	0.787534	0.313513	0.027*
C21	0.4862 (3)	0.5193 (2)	0.8156 (2)	0.0168 (6)
H21A	0.591196	0.534146	0.795601	0.02*
H21B	0.492924	0.562668	0.896988	0.02*
C24	0.3225 (3)	0.0994 (3)	0.7923 (2)	0.0204 (7)
H24	0.2805	0.006461	0.788101	0.024*
C11	0.1438 (3)	0.6029 (3)	0.3371 (2)	0.0224 (7)
H11	0.099895	0.557761	0.260997	0.027*
C18	0.9221 (3)	0.8480 (2)	0.6656 (2)	0.0226 (7)
H18	1.023545	0.870859	0.649451	0.027*
C23	0.2776 (3)	0.1973 (3)	0.8658 (2)	0.0239 (7)
H23	0.204908	0.168795	0.913098	0.029*
B1	0.4511 (3)	0.7520 (3)	0.7450 (3)	0.0153 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O2	0.0199 (11)	0.0149 (10)	0.0135 (10)	0.0035 (8)	0.0013 (8)	0.0025 (8)
C7	0.0131 (15)	0.0146 (15)	0.0167 (15)	−0.0010 (12)	0.0014 (12)	0.0005 (12)
O1	0.0169 (10)	0.0147 (10)	0.0132 (10)	−0.0016 (8)	0.0041 (8)	−0.0008 (8)
N1	0.0138 (12)	0.0135 (12)	0.0141 (12)	0.0002 (9)	0.0017 (10)	0.0012 (9)
N2	0.0325 (15)	0.0179 (14)	0.0204 (14)	0.0036 (11)	0.0096 (12)	0.0061 (11)
C1	0.0124 (15)	0.0148 (15)	0.0151 (15)	0.0013 (12)	0.0020 (12)	0.0038 (12)
C15	0.0188 (15)	0.0087 (14)	0.0155 (15)	0.0021 (11)	0.0023 (12)	0.0002 (11)
C6	0.0158 (15)	0.0140 (15)	0.0131 (14)	0.0009 (12)	0.0021 (12)	0.0043 (12)
C8	0.0127 (14)	0.0195 (15)	0.0113 (14)	−0.0002 (12)	0.0030 (12)	0.0000 (12)
C22	0.0192 (16)	0.0147 (15)	0.0143 (15)	0.0030 (12)	−0.0025 (13)	0.0046 (12)
C20	0.0165 (16)	0.0133 (15)	0.0195 (16)	−0.0007 (12)	0.0029 (13)	0.0018 (12)
C14	0.0213 (16)	0.0119 (14)	0.0131 (14)	0.0016 (12)	0.0041 (12)	−0.0036 (11)
C13	0.0164 (15)	0.0186 (15)	0.0120 (14)	0.0025 (12)	0.0037 (12)	0.0043 (12)
C2	0.0231 (17)	0.0171 (15)	0.0140 (15)	0.0029 (13)	0.0009 (13)	0.0013 (12)
C19	0.0253 (17)	0.0179 (15)	0.0210 (16)	−0.0003 (13)	0.0055 (14)	0.0015 (13)
C3	0.0284 (17)	0.0200 (16)	0.0146 (15)	0.0036 (13)	0.0080 (13)	−0.0008 (12)
C26	0.0182 (16)	0.0173 (16)	0.0209 (16)	0.0019 (12)	0.0071 (13)	0.0052 (12)
C5	0.0200 (16)	0.0170 (15)	0.0196 (16)	−0.0012 (12)	0.0022 (13)	0.0018 (12)
C9	0.0208 (16)	0.0172 (15)	0.0208 (16)	0.0049 (12)	0.0065 (13)	0.0043 (13)
C16	0.0224 (17)	0.0198 (16)	0.0170 (16)	0.0034 (13)	0.0049 (13)	0.0021 (12)
C12	0.0174 (15)	0.0202 (15)	0.0174 (16)	0.0014 (12)	0.0049 (13)	0.0029 (12)
C4	0.0281 (18)	0.0237 (17)	0.0183 (16)	0.0047 (14)	0.0095 (14)	0.0051 (13)
C25	0.0270 (17)	0.0165 (16)	0.0229 (16)	0.0074 (13)	0.0031 (14)	−0.0005 (12)
C17	0.0152 (16)	0.0222 (16)	0.0258 (17)	0.0028 (13)	0.0003 (13)	−0.0001 (13)
C10	0.0196 (16)	0.0322 (17)	0.0162 (16)	0.0085 (13)	0.0012 (13)	0.0056 (13)
C21	0.0193 (15)	0.0170 (15)	0.0137 (15)	0.0050 (12)	−0.0010 (12)	0.0028 (12)
C24	0.0257 (17)	0.0131 (15)	0.0217 (16)	0.0003 (12)	0.0027 (13)	0.0049 (12)
C11	0.0181 (16)	0.0306 (17)	0.0155 (15)	−0.0012 (13)	0.0013 (13)	0.0001 (13)
C18	0.0218 (17)	0.0160 (16)	0.0307 (18)	0.0002 (13)	0.0111 (15)	0.0019 (13)
C23	0.0266 (18)	0.0220 (17)	0.0259 (17)	0.0037 (13)	0.0094 (14)	0.0089 (13)
B1	0.0192 (18)	0.0107 (16)	0.0141 (17)	0.0007 (13)	0.0022 (14)	−0.0022 (13)

Geometric parameters (Å, º) top

O2—C8	1.360 (3)	C2—H2	0.95
O2—B1	1.471 (3)	C19—C18	1.372 (4)
C7—N1	1.497 (3)	C19—H19	0.95
C7—C6	1.504 (3)	C3—C4	1.382 (4)
C7—H7A	0.99	C3—H3	0.95
C7—H7B	0.99	C26—C25	1.389 (4)
O1—C1	1.372 (3)	C26—H26	0.95
O1—B1	1.446 (3)	C5—C4	1.387 (3)
N1—C14	1.501 (3)	C5—H5	0.95
N1—C21	1.517 (3)	C9—C10	1.370 (4)
N1—B1	1.674 (4)	C9—H9	0.95
N2—C23	1.343 (3)	C16—C17	1.381 (4)
N2—C22	1.348 (3)	C16—H16	0.95
C1—C6	1.378 (3)	C12—C11	1.381 (3)
C1—C2	1.396 (3)	C12—H12	0.95
C15—C20	1.396 (3)	C4—H4	0.95
C15—C16	1.396 (3)	C25—C24	1.374 (3)
C15—B1	1.602 (4)	C25—H25	0.95
C6—C5	1.395 (3)	C17—C18	1.383 (3)
C8—C13	1.391 (3)	C17—H17	0.95
C8—C9	1.391 (3)	C10—C11	1.391 (4)
C22—C26	1.383 (3)	C10—H10	0.95
C22—C21	1.513 (3)	C21—H21A	0.99
C20—C19	1.394 (4)	C21—H21B	0.99
C20—H20	0.95	C24—C23	1.371 (3)
C14—C13	1.501 (3)	C24—H24	0.95
C14—H14A	0.99	C11—H11	0.95
C14—H14B	0.99	C18—H18	0.95
C13—C12	1.391 (3)	C23—H23	0.95
C2—C3	1.380 (3)

C8—O2—B1	121.39 (18)	C22—C26—C25	119.4 (2)
N1—C7—C6	111.9 (2)	C22—C26—H26	120.3
N1—C7—H7A	109.2	C25—C26—H26	120.3
C6—C7—H7A	109.2	C4—C5—C6	120.8 (3)
N1—C7—H7B	109.2	C4—C5—H5	119.6
C6—C7—H7B	109.2	C6—C5—H5	119.6
H7A—C7—H7B	107.9	C10—C9—C8	120.3 (2)
C1—O1—B1	120.8 (2)	C10—C9—H9	119.9
C7—N1—C14	108.67 (19)	C8—C9—H9	119.9
C7—N1—C21	110.68 (18)	C17—C16—C15	122.9 (2)
C14—N1—C21	110.23 (16)	C17—C16—H16	118.6
C7—N1—B1	107.64 (16)	C15—C16—H16	118.6
C14—N1—B1	108.46 (18)	C11—C12—C13	121.2 (2)
C21—N1—B1	111.07 (19)	C11—C12—H12	119.4
C23—N2—C22	116.7 (2)	C13—C12—H12	119.4
O1—C1—C6	121.5 (2)	C3—C4—C5	119.5 (3)
O1—C1—C2	118.0 (2)	C3—C4—H4	120.3
C6—C1—C2	120.5 (2)	C5—C4—H4	120.3
C20—C15—C16	115.9 (2)	C24—C25—C26	118.6 (2)
C20—C15—B1	122.7 (2)	C24—C25—H25	120.7
C16—C15—B1	121.2 (2)	C26—C25—H25	120.7
C1—C6—C5	119.0 (2)	C16—C17—C18	119.5 (3)
C1—C6—C7	121.8 (2)	C16—C17—H17	120.3
C5—C6—C7	119.1 (2)	C18—C17—H17	120.3
O2—C8—C13	121.4 (2)	C9—C10—C11	120.4 (2)
O2—C8—C9	118.4 (2)	C9—C10—H10	119.8
C13—C8—C9	120.3 (2)	C11—C10—H10	119.8
N2—C22—C26	122.3 (2)	C22—C21—N1	113.5 (2)
N2—C22—C21	116.5 (2)	C22—C21—H21A	108.9
C26—C22—C21	121.2 (2)	N1—C21—H21A	108.9
C19—C20—C15	121.9 (3)	C22—C21—H21B	108.9
C19—C20—H20	119	N1—C21—H21B	108.9
C15—C20—H20	119	H21A—C21—H21B	107.7
C13—C14—N1	112.13 (17)	C23—C24—C25	118.5 (3)
C13—C14—H14A	109.2	C23—C24—H24	120.8
N1—C14—H14A	109.2	C25—C24—H24	120.8
C13—C14—H14B	109.2	C12—C11—C10	119.2 (3)
N1—C14—H14B	109.2	C12—C11—H11	120.4
H14A—C14—H14B	107.9	C10—C11—H11	120.4
C8—C13—C12	118.6 (2)	C19—C18—C17	119.7 (3)
C8—C13—C14	121.8 (2)	C19—C18—H18	120.1
C12—C13—C14	119.6 (2)	C17—C18—H18	120.1
C3—C2—C1	119.9 (3)	N2—C23—C24	124.5 (3)
C3—C2—H2	120.1	N2—C23—H23	117.8
C1—C2—H2	120.1	C24—C23—H23	117.8
C18—C19—C20	120.1 (3)	O1—B1—O2	108.95 (17)
C18—C19—H19	120	O1—B1—C15	109.5 (2)
C20—C19—H19	120	O2—B1—C15	113.0 (2)
C2—C3—C4	120.3 (2)	O1—B1—N1	107.1 (2)
C2—C3—H3	119.8	O2—B1—N1	104.5 (2)
C4—C3—H3	119.8	C15—B1—N1	113.46 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O1ⁱ	0.95	2.57	3.503 (3)	168
C24—H24···O2ⁱⁱ	0.95	2.50	3.185 (3)	129

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

Structural data and calculated tetrahedral character THC_DA (Å, °) for compounds I–III top

	Compound I	II (MAWDET)^a	III (EROJIF)^b
Bond lengths
B—N	1.674 (4) (B1—N1)	1.674 (5) (B1—N1)	1.641 (2) (B1—N2)
B—O	1.471 (3) (B1—O2)	1.443 (4) (B1—O2)	1.443 (2) (B1—O3)
B—O	1.446 (3) (B1—O1)	1.454 (4) (B1—O1)	1.463 (2) (B1—O5)
B—C	1.602 (4) (B1—C15)	1.608 (5) (B1—C15)	1.425 (2) (B1—O4)
Angles
θ₁	113.0 (2) (C15—B1—O2)	110.3 (3) (C15—B—O2)	113.34 (15) (O4—B1—O3)
θ₂	109.5 (2) (C15—B1—O1)	115.5 (3) (C15—B—O1)	114.47 (16) (O4—B1—O5)
θ₃	109.0 (2) (O2—B1—O1)	109.5 (3) (O2—B—O1)	108.60 (15) (O3—B1—O5)
θ₄	113.5 (2) (N1—B1—C15)	110.0 (3) (N1—B—C15)	105.64 (14) (N2—B1—O4)
θ₅	104.5 (2) (N1—B1—O2)	106.7 (3) (N1—B—O2)	108.45 (14) (N2—B1—O3)
θ₆	107.1 (2) (N1—B1—O1)	104.4 (3) (N1—B—O1)	105.89 (13) (N2—B1—O5)
THC_DA^c	82.8	83.1	79.7

(a) Woodgate et al. (1999); (b) Geng et al. (2011); (c) Höpfl et al. (1999).

Funding information

This work was supported by the National University of Rosario, CONICET and CAPES/CNPQ, Brazil.

References

Barnes, M. J. (1998). Technical Report: Decomposition of Sodium Tetraphenylborate. https://digital. library. unt. edu/ark:/67531/metadc684438/.
Brandenburg, K. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Gawdzik, B., Iwanek, W., Hoser, A. & Woźniak, K. (2009). Z. Kristallogr. 224, 515–518. CSD CrossRef CAS
Geng, Y. & Wu, W. (2011). Acta Cryst. E67, o1380. CSD CrossRef IUCr Journals
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CSD CrossRef IUCr Journals
Höpfl, H. (1999). J. Organomet. Chem. 581, 129–149.
Ledesma, G. N., Anxolabéhère-Mallart, E., Rivière, E., Mallet-Ladeira, S., Hureau, C. & Signorella, S. R. (2014). Inorg. Chem. 53, 2545–2553. CSD CrossRef CAS PubMed
Ledesma, G. N., Eury, H., Anxolabéhère-Mallart, E., Hureau, C. & Signorella, S. R. (2015). J. Inorg. Biochem. 146, 69–76. CrossRef CAS PubMed
Sarina, E. A., Olmstead, M. M., Kanichar, D. & Groziak, M. P. (2015). Acta Cryst. C71, 1085–1088. CSD CrossRef IUCr Journals
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals
Thadani, A. N., Batey, R. A. & Lough, A. J. (2001). Acta Cryst. E57, o762–o763. Web of Science CSD CrossRef IUCr Journals
Woodgate, P., Horner, G., Maynard, N. & Rickard, C. (1999). J. Organomet. Chem. 592, 180–193. CSD CrossRef CAS
Woodgate, P., Horner, G., Maynard, N. & Rickard, C. (2000). J. Organomet. Chem. 595, 215–223. CSD CrossRef CAS
Zhu, L., Shabbir, S., Gray, M., Lynch, V., Sorey, S. & Anslyn, E. (2006). J. Am. Chem. Soc. 128, 1222–1232. CSD CrossRef PubMed CAS

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