Crystallographic characterization of rare-earth cyanotriphenylborate complexes and the cyanoborates [NCBPh3]1−, [NCBPh2Me]1−, and [NCBPh2(μ-O)BPh2]1−

The investigation of the coordination chemistry of rare-earth metal complexes with cyanide ligands led to the isolation and crystallographic characterization of the Ln III cyanotriphenylborate complexes, LnCl2(THF)4(NCBPh3) (Ln = Dy, Y) as well as the cyanoborates [NEt4][B3(μ-O)3(C6H5)4], [NEt4][NCBPh2(μ-O)BPh2], [K(crypt)]2[B3(μ-O)3(C6H5)4][NCBPh2Me]. The [NCBPh2(μ-O)BPh2]1− and (NCBPh2Me)1− anions have not been structurally characterized previously.

Efforts to independently synthesize the tetraethylammonium salt of the (NCBPh 3 ) 1À ligand generated a borate anion and two new cyanophenylborate anions that, to our knowledge, have not been structurally characterized. Specifically, the reaction of BPh 3 and [NEt 4 ] [CN] in THF led to crystals of the cyclic borate, [NEt 4 (-O) 3 Ph 4 ][NCBPh 2 Me], 4. The cyanoborate anions in 3 and 4 have not been previously characterized by X-ray crystallography. The ChemDraw representations of 1-Ln (Ln = Dy, Y), 2, 3, and 4 are depicted in the scheme below.

Synthesis and crystallization
DyCl 2 (THF) 4 (NCBPh 3 ), 1-Dy. In an argon-filled glovebox, KCN (42 mg, 0.642 mmol) was added to a stirred slurry of DyCl 3 (75 mg, 0.279 mmol) in THF (10 mL). NaBPh 4 (96 mg, 0.279 mmol) was added to the stirred slurry. The cloudy white solution was stirred overnight. The volatiles were removed under vacuum. The product was extracted into THF (10 mL) and centrifuged to remove white solids. The clear colorless solution had its volatiles removed under vacuum. The product was isolated as a colorless powder. Colorless crystals of DyCl 2 (THF) 4 (NCBPh 3 ), 1-Dy, suitable for X-ray diffraction, were isolated from a vapor diffusion of hexane into a concentrated THF solution at room temperature after 6 d.
YCl 2 (THF) 4 (NCBPh 3 ), 1-Y. In an argon-filled glovebox, KCN (34 mg, 0.522 mmol) was stirred in THF (10 mL) to form a cloudy white slurry. After 4 h, YCl 3 (51 mg, 0.260 mmol) was tapped into the stirred white slurry. After 5 min, a solution of NaBPh 4 (89 mg, 0.260 mmol) in THF (8 mL) was added to the stirred slurry. The cloudy white slurry was stirred overnight. The white slurry was centrifuged. The clear, colorless supernatant was collected, and the centrifuge pellet was washed with THF (5 mL), and the wash was combined with the supernatant. The colorless solution had its volatiles removed under vacuum. The product was isolated as a colorless solid (107 mg). X-ray quality crystals were isolated from a vapor diffusion of hexane into a concentrated THF solution at room temperature after 10 d.
[NEt 4 ][NCBPh 2 (l-O)BPh 2 ], 3. In an argon-filled glovebox, BPh 3 and NEt 4 CN were added to a BMT-20-S tube drive along with 40 steel balls (6 mm). The reaction mixture was ball milled together for 40 minutes using an Ultra-Turrax Tube Drive at the maximum speed setting. After this time, the colorless solids were extracted into toluene and THF. The volatiles were removed under vacuum. X-ray quality colorless crystals of [NEt 4 ][NCBPh 2 (-O)BPh 2 ], 3, were grown from a slow evaporation of a concentrated THF solution at 258 K after a few days. [

Refinement
General Structure Solution and Refinement. The analytical scattering factors (Wilson, 1992) for neutral atoms were used throughout the analysis. Hydrogen atoms were included using a riding model. DyCl 2 (THF) 4 (NCBPh 3 ), 1-Dy: Data were collected using a 15 sec/frame scan time. There were no systematic absences nor any diffraction symmetry other than the Friedel condition. Atom C5 was disordered and included using multiple components with partial site-occupancy factors. YCl 2 (THF) 4 (NCBPh 3 ), 1-Y: Data were collected using a 30 sec/frame scan time. There were no systematic absences nor any diffraction symmetry other than the Friedel condition. Disordered atoms were included using multiple components with partial site-occupancy-factors. The structure was refined as a two-component twin with occupancy factors 0.513 (1) and 0.487 (1). [NEt 4 ][B 3 (l-O) 3 (C 6 H 5 ) 4 ], 2: Data were collected using a 20 sec/frame scan time. The tetraethylammonium ion was fully disordered. The disordered atoms were included using multiple components with partial site-occupancy factors.

Dichlorido(cyanotriphenylborato-κN)tetrakis(tetrahydrofuran-κO)dysprosium(III) (1-Dy)
Crystal data 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. A colorless crystal of approximate dimensions 0.255 x 0.332 x 0.391 mm was mounted in a cryoloop and transferred to a Bruker SMART APEX II diffractometer. The APEX2 program package was used to determine the unitcell parameters and for data collection (15 sec/frame scan time for a sphere of diffraction data). The raw frame data was processed using SAINT and SADABS to yield the reflection data file. Subsequent calculations were carried out using the SHELXTL program. There were no systematic absences nor any diffraction symmetry other than the Friedel condition. The centrosymmetric triclinic space group P-1 was assigned and later determined to be correct. The structure was solved by dual space methods and refined on F2 by full-matrix least-squares techniques. The analytical scattering factors for neutral atoms were used throughout the analysis. Hydrogen atoms were included using a riding model. Atom C(5) was disordered and included using multiple components with partial site-occupancy-factors. Least-squares analysis yielded wR2 = 0.0609 and Goof = 1.042 for 406 variables refined against 8460 data (0.74Å), R1 = 0.0239 for those 7562 data with I > 2.0sigma(I).

Dichlorido(cyanotriphenylborato-κN)tetrakis(tetrahydrofuran-κO)ytterbium(III) (1-Y)
Crystal data  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.64 e Å −3 Δρ min = −0.80 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. A colorless crystal of approximate dimensions 0.126 x 0.198 x 0.324 mm was mounted on a glass fiber and transferred to a Bruker SMART APEX II diffractometer system. The APEX2 program package and the CELL_NOW were used to determine the unit-cell parameters. Data was collected using a 30 sec/frame scan time. The raw frame data was processed using SAINT3 and TWINABS to yield the reflection data file (HKLF5 format). Subsequent calculations were carried out using the SHELXTL program package. There were no systematic absences nor any diffraction symmetry other than the Friedel condition The centrosymmetric triclinic space group P-1 was assigned and later determined to be correct. The structure was solved by direct methods and refined on F2 by full-matrix least-squares techniques. The analytical scattering factors for neutral atoms were used throughout the analysis. Hydrogen atoms were included using a riding model. Disordered atoms were included using multiple components with partial site-occupancy-factors. Least-squares analysis yielded wR2 = 0.1023 and Goof = 1.037 for 425 variables refined against 7988 data (0.77 ), R1 = 0.0470 for those 6188 with I > 2.0sigma(I). The structure was refined as a two-component twin, BASF = 0.4868.

sup-8
Acta Cryst. (2021). E77, 799-803 Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 ) 0.23233 (7) 0.07981 (7) 0.55775 (7) 0.0330 (2)  Cl2 0.25375 (7) 0.40279 (7) 0.41725 (7) (6) C16B-C17-O4 106.2 (7) N1-Y1-Cl1 100.28 (7) O4-C17-C16 103.9 (4) Cl2-Y1-Cl1 119.6 (4) C20-C21- 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. A colorless crystal of approximate dimensions 0.228 x 0.331 x 0.367 mm was mounted on a glass fiber and transferred to a Bruker SMART APEX II diffractometer. The APEX2 program package was used to determine the unitcell parameters and for data collection (20 sec/frame scan time for a sphere of diffraction data). The raw frame data was processed using SAINT and SADABS to yield the reflection data file. Subsequent calculations were carried out using the SHELXTL program. The diffraction symmetry was 2/m and the systematic absences were consistent with the monoclinic space group P21/n that was later determined to be correct. The structure was solved by dual space methods and refined on F2 by full-matrix least-squares techniques. The analytical scattering factors for neutral atoms were used throughout the analysis. Hydrogen atoms were included using a riding model. The tetraethylammonium ion was fully disordered. The disordered atoms were included using multiple components with partial site-occupancy-factors. Least-squares analysis yielded wR2 = 0.1785 and Goof = 1.017 for 442 variables refined against 5959 data (0.80 Å), R1 = 0.0639 for those 5030 data with I > 2.0sigma(I).  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.41 e Å −3 Δρ min = −0.24 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. A colorless crystal of approximate dimensions 0.216 x 0.265 x 0.280 mm was mounted in a cryoloop and transferred to a Bruker SMART APEX II diffractometer. The APEX2 program package was used to determine the unitcell parameters and for data collection (30 sec/frame scan time for a sphere of diffraction data). The raw frame data was processed using SAINT and SADABS to yield the reflection data file. Subsequent calculations were carried out using the SHELXTL program. The diffraction symmetry was 2/m and the systematic absences were consistent with the monoclinic space group P21/n that was later determined to be correct. The structure was solved by dual space methods and refined on F2 by full-matrix least-squares techniques. The analytical scattering factors for neutral atoms were used throughout the analysis. Hydrogen atoms were included using a riding model. Least-squares analysis yielded wR2 = 0.1188 and Goof = 1.038 for 347 variables refined against 7242 data (0.73 Å), R1 = 0.0476 for those 5500 data with I > 2.0sigma(I).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq O1 0.54584 (8) 0.23892 (7)  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. A colorless crystal of approximate dimensions 0.280 x 0.325 x 0.454 mm was mounted in a cryoloop and transferred to a Bruker SMART APEX II diffractometer. The APEX2 program package was used to determine the unitcell parameters and for data collection (60 sec/frame scan time for a sphere of diffraction data). The raw frame data was processed using SAINT and SADABS to yield the reflection data file. Subsequent calculations were carried out using the SHELXTL program. The diffraction symmetry was mmm and the systematic absences were consistent with the orthorhombic space groups Pbcm and Pca21. It was later determined that space group Pca21 was correct. The structure was solved by dual space methods and refined on F2 by full-matrix least-squares techniques. The analytical scattering factors for neutral atoms were used throughout the analysis. Hydrogen atoms were included using a riding model. There were two molecules of tetrahydrofuran solvent present. One solvent molecule was disordered and included using multiple components with partial site-occupancy-factors. Least-squares analysis yielded wR2 = 0.2089 and Goof = 1.064 for 988 variables refined against 15958 data (0.82 Å), R1 = 0.0742 for those 14236 data with I > 2.0sigma(I). The structure was refined as a two component inversion twin.