organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

2-[4-(Di­methyl­amino)­phen­yl]-3,3-di­fluoro-3H-naphtho­[1,2-e][1,3,2]oxaza­borinin-2-ium-3-uide

aFaculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland, and bFaculty of Chemical Technology and Engineering, UniVersity of Technology and Life Sciences, Seminaryjna 3, 85-326 Bydgoszcz, Poland
*Correspondence e-mail: bzarychta@uni.opole.pl

Edited by I. Brito, University of Antofagasta, Chile (Received 26 July 2017; accepted 2 August 2017; online 8 August 2017)

In the title compound, C19H17BF2N2O, a twist about the N—C single bond is observed, making the cross conjugation not as efficient as in the case of a planar structure. The borone complex has tetra­hedral geometry. In the crystal, mol­ecules are conected by weak C—H⋯F hydrogen bonds.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

The organic fluoro­phores commonly known as BODIPY dyes are a class of compounds that are characterized by intense fluorescence, high stability and relatively small Stokes shifts. On the other hand, the difluoroborates that are hy­droxy Schiff base derivatives are also important flurophores. It is known that benzannulation and the presence of a strong electron-donating group shift the maxima of absorption and emission towards the red part of the spectrum (Fabian & Hartmann, 1980[Fabian, J. & Hartmann, H. (1980). Light Absorption of Organic Colorants - Theoretical Treatment and Empirical Rules. Berlin, Heidelberg, New York: Springer-Verlag.]). On the other hand, elongation of the mol­ecule by a π-conjugated spacer also gives similar effect. In such a case, the presence of single bonds gives an the opportunity for rotation while the presence of the –CH=CH– moiety introduces the possibility of photoisomerization. The last two features cause the fluorescence to be less intensive than in rigid compounds. The rigidification of the mol­ecular skeleton may be realized by benzannulation, which is seen in the vibrationally resolved absorption spectra (Grabarz et al., 2016[Grabarz, A. M., Laurent, A. D., Jędrzejewska, B., Zakrzewska, A., Jacquemin, D. & Ośmiałowski, B. (2016). J. Org. Chem. 81, 2280-2292.]; Ośmiałowski et al., 2015[Ośmiałowski, B., Zakrzewska, A., Jędrzejewska, B., Grabarz, A., Zaleśny, R., Bartkowiak, W. & Kolehmainen, E. (2015). J. Org. Chem. 80, 2072-2080.]). In any case, the geometry of mol­ecules in their ground state is the most fundamental property that should be considered.

There is one independent mol­ecule in the asymmetric unit of the title compound. Its mol­ecular structure is shown in Fig. 1[link]. In the crystal, there is only one classical inter­molecular hydrogen bond (Table 1[link]), which connects mol­ecules into zigzag chains along the [101] direction (see Fig. 2[link]). The chains are connected to each other by weak van der Waals inter­actions.

Table 1
Hydrogen-bond geometry (Å, °) [The intramolecular H bond does not appear to be mentioned in the text]

D—H⋯A D—H H⋯A DA D—H⋯A
C2—H2⋯F1i 0.93 2.61 3.3138 (13) 133
C17—H17⋯F2 0.93 2.56 3.1938 (13) 125
Symmetry code: (i) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}].
[Figure 1]
Figure 1
The mol­ecular structure of the title compound, with displacement ellipsoids drawn at the 50% probability level.
[Figure 2]
Figure 2
The crystal packing of the title compound, viewed along the c axis.

The geometry of the 4-(di­methyl­amino)­phenyl and naphthalene groups is typical (Allen, 2002[Allen, F. H. (2002). Acta Cryst. B58, 380-388.]). The groups are not co-planar, the dihedral angle between them being 55.12 (3)°. A twist about the N1—C12 single bond is observed, making the cross conjugation not as efficient as in the case of a planar structure. The geometry around B1 atom is tetra­hedral and exhibits normal bond distances and angles (Lugo & Richards, 2010[Lugo née Gushwa, A. F. & Richards, A. F. (2010). Eur. J. Inorg. Chem. pp. 2025-2035.]). The B—N distance [1.589 (2) Å] is notably longer than a normal B1—N1 single bond (ca 1.52 Å; Singh et al., 1986[Singh, Y. P., Rupani, P., Singh, A., Rai, A. K., Mehrotra, R. C., Rogers, R. D. & Atwood, J. L. (1986). Inorg. Chem. 25, 3076-3081.]; Lugo & Richards, 2010[Lugo née Gushwa, A. F. & Richards, A. F. (2010). Eur. J. Inorg. Chem. pp. 2025-2035.]), indicating weak bonding, and the B1—O1 bond is slightly shorter [1.460 (2) versus 1.48 Å]. This pattern of bond lengths is contrary to the model of Itoh and co-workers where the B—O bond is shorter and B—N bond is markedly longer (Itoh et al., 1998[Itoh, K., Fujimoto, M. & Hashimoto, M. (1998). Acta Cryst. C54, 1324-1327.]), indicating that the complex adopts a structure close to an enol tautomer.

Synthesis and crystallization

The synthesis of 2-[4-(di­methyl­amino)­phen­yl]-3,3-di­fluoro-3H-naphtho­[1,2-e][1,3,2]oxaza­borinin-2-ium-3-uide was performed by the condensation of 2-hy­droxy-1-naphtaldehyde (1 g) with N,N-dimethyl-p-phenyl­enedi­amine (0.79 g) in anhydrous methanol (10 ml) as a solvent by heating the mixture at boiling point for 12 h. The resulting precipitate was re-crystallized from methanol (m.p. 168.9–171.2°C). The resulting Schiff base (0.67 g, 85%) was treated with BF3 etherate (1 ml) in chloro­form (10 ml) and DIEA (1 ml). The reaction mixture was heated at boiling point for 5 h and 5 ml of Na2CO3 (saturated) was added to decompose the excess of BF3 and neutralize HF. The organic layer was separated and the remaining water layer was extracted with three portions of chloro­form. The combined chloro­form fractions were evaporated to dryness and next under vacuum to remove DIEA. The remaining solid was purified by flash chromatography on SiO2 with chloro­form as eluent. NMR spectra were recorded using CDCl3 as a solvent. Crystals of good quality (m.p. 208–209.3°C) were obtained by slow evaporation of a CDCl3 solution in the NMR tube.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C19H17BF2N2O
Mr 338.15
Crystal system, space group Monoclinic, P21/n
Temperature (K) 100
a, b, c (Å) 9.6529 (4), 17.7072 (5), 10.4833 (4)
β (°) 114.106 (4)
V3) 1635.60 (11)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.10
Crystal size (mm) 0.25 × 0.23 × 0.15
 
Data collection
Diffractometer Oxford Diffraction Xcalibur
Absorption correction
No. of measured, independent and observed [I > 2σ(I)] reflections 10886, 3196, 2485
Rint 0.022
(sin θ/λ)max−1) 0.617
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.080, 0.98
No. of reflections 3196
No. of parameters 228
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.18, −0.20
Computer programs: CrysAlis CCD and CrysAlis RED (Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2014 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]) and SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]).

Structural data


Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015b).

(I) top
Crystal data top
C19H17BF2N2OF(000) = 704
Mr = 338.15Dx = 1.373 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 9.6529 (4) ÅCell parameters from 10886 reflections
b = 17.7072 (5) Åθ = 3.3–26.0°
c = 10.4833 (4) ŵ = 0.10 mm1
β = 114.106 (4)°T = 100 K
V = 1635.60 (11) Å3Irregular, colourless
Z = 40.25 × 0.23 × 0.15 mm
Data collection top
Oxford Diffraction Xcalibur
diffractometer
2485 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.022
Detector resolution: 1024 x 1024 with blocks 2 x 2 pixels mm-1θmax = 26.0°, θmin = 3.3°
ω scanh = 1111
10886 measured reflectionsk = 2117
3196 independent reflectionsl = 1212
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.031H-atom parameters constrained
wR(F2) = 0.080 w = 1/[σ2(Fo2) + (0.0519P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.98(Δ/σ)max = 0.001
3196 reflectionsΔρmax = 0.18 e Å3
228 parametersΔρmin = 0.20 e Å3
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. All H atoms were found in a difference map but set to idealized positions and treated as riding with CAr—H = 0.93 Å and Uiso(H) = 1.2Ueq(C) for C—H and with C—H3 = 0.96 Å and Uiso(H) = 1.5Ueq(C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.67086 (9)0.34092 (4)0.45068 (8)0.0198 (2)
F10.87188 (8)0.37674 (4)0.65386 (7)0.0293 (2)
F20.63047 (8)0.39784 (4)0.63418 (7)0.0302 (2)
B10.72560 (16)0.39555 (7)0.56491 (14)0.0196 (3)
N10.72551 (10)0.47697 (5)0.50108 (9)0.0161 (2)
N21.08863 (11)0.71216 (5)0.83259 (10)0.0235 (2)
C10.56665 (13)0.35922 (6)0.32362 (12)0.0175 (3)
C20.48595 (13)0.30025 (6)0.23360 (13)0.0210 (3)
H20.50400.25040.26350.025*
C30.38129 (13)0.31661 (7)0.10243 (12)0.0208 (3)
H30.32840.27730.04410.025*
C40.35069 (13)0.39207 (6)0.05228 (12)0.0180 (3)
C50.23941 (13)0.40864 (7)0.08298 (12)0.0212 (3)
H50.18610.36940.14130.025*
C60.20910 (13)0.48159 (7)0.12919 (12)0.0216 (3)
H60.13620.49170.21840.026*
C70.28848 (13)0.54113 (7)0.04138 (12)0.0199 (3)
H70.26820.59060.07320.024*
C80.39571 (12)0.52711 (6)0.09082 (12)0.0177 (3)
H80.44610.56730.14800.021*
C90.43083 (12)0.45235 (6)0.14152 (12)0.0160 (2)
C100.54181 (12)0.43441 (6)0.27937 (11)0.0157 (2)
C110.63361 (12)0.49104 (6)0.37190 (12)0.0164 (3)
H110.62780.54020.33880.020*
C120.82088 (12)0.53630 (6)0.58513 (11)0.0164 (3)
C130.89989 (12)0.58379 (6)0.53311 (11)0.0178 (3)
H130.89430.57610.44340.021*
C140.98708 (13)0.64254 (6)0.61356 (12)0.0193 (3)
H141.03910.67390.57690.023*
C150.99802 (13)0.65550 (6)0.75010 (12)0.0180 (3)
C160.91852 (13)0.60575 (7)0.80092 (12)0.0202 (3)
H160.92380.61260.89070.024*
C170.83328 (13)0.54721 (6)0.72075 (12)0.0187 (3)
H170.78350.51460.75760.022*
C181.14248 (15)0.77096 (7)0.76815 (13)0.0293 (3)
H18A1.20520.74900.72670.044*
H18B1.20050.80710.83780.044*
H18C1.05740.79580.69720.044*
C191.08519 (15)0.72867 (7)0.96778 (13)0.0299 (3)
H19A0.98410.74290.95420.045*
H19B1.15370.76941.01190.045*
H19C1.11540.68461.02610.045*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0213 (4)0.0160 (4)0.0181 (4)0.0008 (3)0.0041 (4)0.0012 (3)
F10.0289 (4)0.0209 (4)0.0242 (4)0.0021 (3)0.0032 (3)0.0030 (3)
F20.0444 (5)0.0246 (4)0.0299 (4)0.0075 (3)0.0235 (4)0.0028 (3)
B10.0229 (7)0.0162 (7)0.0172 (7)0.0006 (5)0.0056 (6)0.0008 (5)
N10.0144 (5)0.0162 (5)0.0161 (5)0.0000 (4)0.0046 (4)0.0010 (4)
N20.0272 (6)0.0206 (5)0.0202 (6)0.0052 (4)0.0069 (5)0.0050 (4)
C10.0160 (6)0.0193 (6)0.0177 (6)0.0008 (5)0.0074 (5)0.0012 (5)
C20.0237 (7)0.0148 (6)0.0244 (7)0.0006 (5)0.0098 (5)0.0009 (5)
C30.0202 (6)0.0193 (6)0.0223 (6)0.0044 (5)0.0080 (5)0.0066 (5)
C40.0142 (6)0.0215 (6)0.0191 (6)0.0017 (5)0.0074 (5)0.0037 (5)
C50.0165 (6)0.0252 (6)0.0201 (6)0.0021 (5)0.0057 (5)0.0068 (5)
C60.0163 (6)0.0300 (7)0.0158 (6)0.0036 (5)0.0038 (5)0.0013 (5)
C70.0194 (6)0.0219 (6)0.0191 (6)0.0037 (5)0.0085 (5)0.0016 (5)
C80.0153 (6)0.0185 (6)0.0180 (6)0.0012 (5)0.0055 (5)0.0026 (5)
C90.0131 (6)0.0195 (6)0.0169 (6)0.0007 (5)0.0074 (5)0.0021 (5)
C100.0145 (6)0.0166 (6)0.0163 (6)0.0004 (5)0.0067 (5)0.0007 (5)
C110.0150 (6)0.0156 (6)0.0178 (6)0.0019 (4)0.0059 (5)0.0015 (5)
C120.0129 (6)0.0157 (6)0.0173 (6)0.0019 (4)0.0029 (5)0.0001 (5)
C130.0180 (6)0.0192 (6)0.0130 (6)0.0028 (5)0.0030 (5)0.0010 (5)
C140.0190 (6)0.0173 (6)0.0200 (6)0.0004 (5)0.0063 (5)0.0023 (5)
C150.0148 (6)0.0162 (6)0.0189 (6)0.0027 (4)0.0026 (5)0.0011 (5)
C160.0175 (6)0.0259 (7)0.0170 (6)0.0022 (5)0.0068 (5)0.0023 (5)
C170.0159 (6)0.0206 (6)0.0199 (6)0.0003 (5)0.0077 (5)0.0005 (5)
C180.0327 (8)0.0199 (7)0.0294 (7)0.0066 (6)0.0067 (6)0.0041 (5)
C190.0323 (8)0.0283 (7)0.0269 (7)0.0050 (6)0.0100 (6)0.0124 (6)
Geometric parameters (Å, º) top
O1—C11.3404 (14)C7—H70.9300
O1—B11.4602 (15)C8—C91.4152 (16)
F1—B11.3779 (15)C8—H80.9300
F2—B11.3846 (15)C9—C101.4396 (15)
B1—N11.5892 (16)C10—C111.4246 (15)
N1—C111.3045 (14)C11—H110.9300
N1—C121.4369 (14)C12—C131.3878 (16)
N2—C151.3789 (14)C12—C171.3907 (15)
N2—C181.4483 (15)C13—C141.3863 (16)
N2—C191.4607 (15)C13—H130.9300
C1—C101.3981 (15)C14—C151.4105 (16)
C1—C21.4096 (16)C14—H140.9300
C2—C31.3641 (17)C15—C161.4081 (16)
C2—H20.9300C16—C171.3759 (16)
C3—C41.4221 (16)C16—H160.9300
C3—H30.9300C17—H170.9300
C4—C51.4165 (16)C18—H18A0.9600
C4—C91.4218 (16)C18—H18B0.9600
C5—C61.3685 (17)C18—H18C0.9600
C5—H50.9300C19—H19A0.9600
C6—C71.4036 (16)C19—H19B0.9600
C6—H60.9300C19—H19C0.9600
C7—C81.3718 (16)
C1—O1—B1121.89 (9)C8—C9—C10123.32 (10)
F1—B1—F2111.59 (10)C4—C9—C10118.47 (10)
F1—B1—O1108.81 (10)C1—C10—C11118.02 (10)
F2—B1—O1110.74 (10)C1—C10—C9119.98 (10)
F1—B1—N1109.17 (10)C11—C10—C9121.95 (10)
F2—B1—N1107.93 (9)N1—C11—C10122.86 (10)
O1—B1—N1108.53 (9)N1—C11—H11118.6
C11—N1—C12119.38 (9)C10—C11—H11118.6
C11—N1—B1119.58 (9)C13—C12—C17119.07 (10)
C12—N1—B1121.00 (9)C13—C12—N1121.29 (10)
C15—N2—C18119.15 (10)C17—C12—N1119.64 (10)
C15—N2—C19119.61 (10)C14—C13—C12120.68 (10)
C18—N2—C19117.60 (9)C14—C13—H13119.7
O1—C1—C10121.15 (10)C12—C13—H13119.7
O1—C1—C2118.13 (10)C13—C14—C15120.98 (11)
C10—C1—C2120.69 (11)C13—C14—H14119.5
C3—C2—C1119.80 (11)C15—C14—H14119.5
C3—C2—H2120.1N2—C15—C16121.47 (11)
C1—C2—H2120.1N2—C15—C14121.35 (10)
C2—C3—C4121.91 (11)C16—C15—C14117.11 (10)
C2—C3—H3119.0C17—C16—C15121.51 (11)
C4—C3—H3119.0C17—C16—H16119.2
C5—C4—C9119.31 (11)C15—C16—H16119.2
C5—C4—C3121.52 (10)C16—C17—C12120.63 (11)
C9—C4—C3119.15 (11)C16—C17—H17119.7
C6—C5—C4120.99 (11)C12—C17—H17119.7
C6—C5—H5119.5N2—C18—H18A109.5
C4—C5—H5119.5N2—C18—H18B109.5
C5—C6—C7119.76 (11)H18A—C18—H18B109.5
C5—C6—H6120.1N2—C18—H18C109.5
C7—C6—H6120.1H18A—C18—H18C109.5
C8—C7—C6120.74 (11)H18B—C18—H18C109.5
C8—C7—H7119.6N2—C19—H19A109.5
C6—C7—H7119.6N2—C19—H19B109.5
C7—C8—C9120.99 (10)H19A—C19—H19B109.5
C7—C8—H8119.5N2—C19—H19C109.5
C9—C8—H8119.5H19A—C19—H19C109.5
C8—C9—C4118.20 (10)H19B—C19—H19C109.5
C1—O1—B1—F1151.50 (10)O1—C1—C10—C9179.02 (10)
C1—O1—B1—F285.50 (13)C2—C1—C10—C91.17 (16)
C1—O1—B1—N132.81 (14)C8—C9—C10—C1177.88 (10)
F1—B1—N1—C11143.57 (10)C4—C9—C10—C11.18 (16)
F2—B1—N1—C1194.96 (12)C8—C9—C10—C114.96 (16)
O1—B1—N1—C1125.11 (14)C4—C9—C10—C11175.99 (10)
F1—B1—N1—C1238.90 (14)C12—N1—C11—C10176.32 (10)
F2—B1—N1—C1282.57 (12)B1—N1—C11—C106.11 (16)
O1—B1—N1—C12157.36 (9)C1—C10—C11—N18.74 (16)
B1—O1—C1—C1021.42 (16)C9—C10—C11—N1174.03 (10)
B1—O1—C1—C2160.67 (11)C11—N1—C12—C1344.76 (15)
O1—C1—C2—C3178.63 (10)B1—N1—C12—C13137.71 (11)
C10—C1—C2—C30.71 (17)C11—N1—C12—C17134.44 (11)
C1—C2—C3—C40.29 (18)B1—N1—C12—C1743.09 (15)
C2—C3—C4—C5178.58 (11)C17—C12—C13—C141.59 (16)
C2—C3—C4—C90.32 (17)N1—C12—C13—C14177.62 (10)
C9—C4—C5—C60.60 (17)C12—C13—C14—C150.10 (17)
C3—C4—C5—C6178.85 (11)C18—N2—C15—C16167.37 (11)
C4—C5—C6—C70.39 (17)C19—N2—C15—C169.36 (17)
C5—C6—C7—C80.38 (17)C18—N2—C15—C1415.88 (16)
C6—C7—C8—C90.94 (17)C19—N2—C15—C14173.89 (11)
C7—C8—C9—C40.71 (16)C13—C14—C15—N2177.72 (10)
C7—C8—C9—C10179.77 (11)C13—C14—C15—C160.83 (16)
C5—C4—C9—C80.05 (15)N2—C15—C16—C17177.17 (11)
C3—C4—C9—C8178.35 (10)C14—C15—C16—C170.28 (17)
C5—C4—C9—C10179.05 (10)C15—C16—C17—C121.21 (17)
C3—C4—C9—C100.76 (15)C13—C12—C17—C162.14 (17)
O1—C1—C10—C111.74 (16)N1—C12—C17—C16177.08 (10)
C2—C1—C10—C11176.11 (10)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···F1i0.932.613.3138 (13)133
C17—H17···F20.932.563.1938 (13)125
Symmetry code: (i) x1/2, y+1/2, z1/2.
 

References

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