Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104007693/hj1003sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270104007693/hj1003Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270104007693/hj1003IIsup3.hkl |
CCDC references: 243591; 243592
Compound (I) was prepared by reduction of the iminomethyl precursor under the action of 2.5 equivalents of LiAlH4 in ether as solvent. The formation of the product at room temperature was followed via thin-layer chromatography analysis, and took about 8–12 h. The reaction was quenched by the addition of ice to the reaction mixture. Ether was removed in vacuo, followed by extraction with dichloromethane and water, and the product was isolated with flash silica chromatography in a yield of 80%. Compound (II) was synthesized by treatment of (I) in dry tetrahydrofuran with 1.1 mole equivalents of n-butyllithium at 195 K, followed by the addition of 1.1 equivalents of methyl iodide. After 2 h, the reaction was quenched using water, and the tetrahydrofuran was removed in vacuo. Dichloromethane and water were used to extract the product, which was purified via flash silica chromatography and obtained in a yield of 65%. For both compounds, crystals were obtained from solutions in hexane.
The aromatic, methylene and methyl H atoms were placed in geometrically idealized positions (C—H = 0.97–0.98 Å) and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C). The positions of the imine H atoms were determined from a difference Fourier map.
For both compounds, data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus and XPREP (Bruker, 1999). Program(s) used to solve structure: SIR2002 (Burla et al., 2003) for (I); SIR2002 (Altomare et al., 2003) for (II). For both compounds, program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg & Berndt, 2001); software used to prepare material for publication: WinGX (Farrugia, 1999).
C25H22NP | F(000) = 1552 |
Mr = 367.41 | Dx = 1.226 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C2yc | Cell parameters from 789 reflections |
a = 22.174 (4) Å | θ = 2.7–21.5° |
b = 7.9968 (16) Å | µ = 0.15 mm−1 |
c = 22.519 (5) Å | T = 293 K |
β = 94.50 (3)° | Plates, colourless |
V = 3980.7 (14) Å3 | 0.38 × 0.24 × 0.04 mm |
Z = 8 |
Bruker SMART 1K CCD area-detector diffractometer | 2201 reflections with I > 2σ(I) |
Radiation source: rotating anode | Rint = 0.075 |
ω scans | θmax = 28.4°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | h = −29→29 |
Tmin = 0.95, Tmax = 0.97 | k = −10→10 |
16110 measured reflections | l = −30→24 |
4943 independent reflections |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.046 | w = 1/[σ2(Fo2) + (0.0411P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.103 | (Δ/σ)max = 0.001 |
S = 0.86 | Δρmax = 0.15 e Å−3 |
4943 reflections | Δρmin = −0.19 e Å−3 |
248 parameters |
C25H22NP | V = 3980.7 (14) Å3 |
Mr = 367.41 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 22.174 (4) Å | µ = 0.15 mm−1 |
b = 7.9968 (16) Å | T = 293 K |
c = 22.519 (5) Å | 0.38 × 0.24 × 0.04 mm |
β = 94.50 (3)° |
Bruker SMART 1K CCD area-detector diffractometer | 4943 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 2201 reflections with I > 2σ(I) |
Tmin = 0.95, Tmax = 0.97 | Rint = 0.075 |
16110 measured reflections |
R[F2 > 2σ(F2)] = 0.046 | 0 restraints |
wR(F2) = 0.103 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.86 | Δρmax = 0.15 e Å−3 |
4943 reflections | Δρmin = −0.19 e Å−3 |
248 parameters |
Experimental. The intensity data for I were collected on a Siemens SMART CCD 1 K diffractometer using an exposure time of 20 s/frame. A total of 2150 frames were collected with a frame width of 0.2° covering up to θ = 28.36° with 99.4% completeness accomplished. The first 50 frames were recollected at the end of each data collection to check for decay; none was found. |
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. |
x | y | z | Uiso*/Ueq | ||
P | 0.08620 (2) | 0.22436 (7) | 0.10666 (2) | 0.04918 (17) | |
N | 0.02530 (9) | 0.3652 (2) | −0.08252 (7) | 0.0615 (5) | |
C13 | 0.09251 (8) | 0.0868 (2) | 0.04207 (8) | 0.0431 (5) | |
C01 | 0.11279 (10) | 0.0904 (2) | 0.16913 (8) | 0.0502 (5) | |
C18 | 0.06864 (8) | 0.1419 (2) | −0.01423 (8) | 0.0434 (5) | |
C07 | 0.15072 (8) | 0.3650 (2) | 0.10155 (7) | 0.0448 (5) | |
C08 | 0.15236 (10) | 0.5100 (2) | 0.13583 (8) | 0.0542 (6) | |
H08 | 0.1209 | 0.5326 | 0.1596 | 0.065* | |
C20 | 0.06838 (10) | 0.4361 (2) | −0.11593 (8) | 0.0488 (5) | |
C16 | 0.09611 (10) | −0.1229 (3) | −0.05682 (10) | 0.0613 (6) | |
H16 | 0.0971 | −0.1924 | −0.0898 | 0.074* | |
C09 | 0.20008 (11) | 0.6209 (3) | 0.13514 (9) | 0.0629 (6) | |
H09 | 0.2006 | 0.7165 | 0.1587 | 0.075* | |
C19 | 0.04011 (9) | 0.3135 (3) | −0.02142 (8) | 0.0559 (6) | |
H19A | 0.0034 | 0.3148 | −0.0007 | 0.067* | |
H19B | 0.0676 | 0.3949 | −0.0023 | 0.067* | |
C06 | 0.17079 (10) | 0.0911 (2) | 0.19630 (9) | 0.0574 (6) | |
H06 | 0.2 | 0.1596 | 0.1814 | 0.069* | |
C12 | 0.19853 (9) | 0.3374 (3) | 0.06684 (9) | 0.0593 (6) | |
H12 | 0.1987 | 0.2413 | 0.0436 | 0.071* | |
C21 | 0.12973 (9) | 0.4280 (2) | −0.09905 (9) | 0.0538 (5) | |
H21 | 0.143 | 0.3732 | −0.064 | 0.065* | |
C17 | 0.07146 (9) | 0.0358 (3) | −0.06269 (8) | 0.0547 (5) | |
H17 | 0.0564 | 0.0724 | −0.1002 | 0.066* | |
C14 | 0.11712 (9) | −0.0722 (2) | 0.04693 (9) | 0.0553 (5) | |
H14 | 0.1327 | −0.1098 | 0.0841 | 0.066* | |
C10 | 0.24634 (11) | 0.5913 (3) | 0.10028 (10) | 0.0690 (6) | |
H10 | 0.2782 | 0.6669 | 0.0996 | 0.083* | |
C15 | 0.11921 (9) | −0.1765 (3) | −0.00157 (10) | 0.0628 (6) | |
H15 | 0.1361 | −0.2826 | 0.003 | 0.075* | |
C25 | 0.04999 (11) | 0.5184 (3) | −0.16886 (9) | 0.0620 (6) | |
H25 | 0.0091 | 0.5247 | −0.1814 | 0.074* | |
C11 | 0.24577 (10) | 0.4487 (3) | 0.06592 (10) | 0.0740 (7) | |
H11 | 0.2773 | 0.4277 | 0.0421 | 0.089* | |
C05 | 0.18624 (12) | −0.0091 (3) | 0.24556 (10) | 0.0759 (7) | |
H05 | 0.2255 | −0.0069 | 0.2634 | 0.091* | |
C23 | 0.15288 (14) | 0.5818 (3) | −0.18525 (11) | 0.0779 (7) | |
H23 | 0.1811 | 0.6307 | −0.2083 | 0.093* | |
C24 | 0.09213 (14) | 0.5902 (3) | −0.20248 (10) | 0.0757 (7) | |
H24 | 0.0793 | 0.6454 | −0.2376 | 0.091* | |
C22 | 0.17122 (11) | 0.4998 (3) | −0.13332 (11) | 0.0687 (6) | |
H22 | 0.2122 | 0.4928 | −0.1213 | 0.082* | |
C02 | 0.07125 (12) | −0.0126 (3) | 0.19318 (10) | 0.0816 (8) | |
H02 | 0.0316 | −0.0142 | 0.1763 | 0.098* | |
C04 | 0.14409 (16) | −0.1106 (3) | 0.26785 (11) | 0.0905 (9) | |
H04 | 0.1545 | −0.1775 | 0.3008 | 0.109* | |
C03 | 0.08701 (14) | −0.1132 (4) | 0.24164 (12) | 0.0991 (9) | |
H03 | 0.0583 | −0.1834 | 0.2564 | 0.119* | |
H1 | −0.0112 (10) | 0.402 (3) | −0.0913 (9) | 0.074 (8)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
P | 0.0519 (3) | 0.0544 (4) | 0.0414 (3) | 0.0045 (3) | 0.0047 (2) | −0.0038 (2) |
N | 0.0484 (12) | 0.0870 (14) | 0.0487 (11) | 0.0118 (11) | 0.0019 (9) | 0.0168 (9) |
C13 | 0.0439 (11) | 0.0440 (12) | 0.0417 (11) | −0.0025 (10) | 0.0048 (9) | −0.0026 (9) |
C01 | 0.0586 (14) | 0.0560 (13) | 0.0360 (11) | −0.0005 (11) | 0.0045 (10) | −0.0055 (9) |
C18 | 0.0370 (11) | 0.0523 (12) | 0.0414 (12) | −0.0072 (10) | 0.0054 (9) | −0.0007 (10) |
C07 | 0.0543 (13) | 0.0414 (12) | 0.0379 (11) | 0.0054 (10) | −0.0014 (9) | −0.0024 (9) |
C08 | 0.0677 (15) | 0.0507 (13) | 0.0440 (12) | 0.0109 (12) | 0.0040 (10) | −0.0044 (10) |
C20 | 0.0586 (14) | 0.0468 (12) | 0.0413 (12) | 0.0086 (11) | 0.0044 (10) | −0.0018 (9) |
C16 | 0.0726 (16) | 0.0586 (15) | 0.0538 (14) | −0.0172 (12) | 0.0118 (11) | −0.0191 (11) |
C09 | 0.0816 (17) | 0.0421 (13) | 0.0629 (14) | 0.0045 (13) | −0.0072 (13) | −0.0115 (10) |
C19 | 0.0524 (13) | 0.0702 (15) | 0.0460 (13) | 0.0102 (11) | 0.0102 (10) | 0.0073 (10) |
C06 | 0.0703 (16) | 0.0542 (13) | 0.0472 (13) | 0.0021 (12) | 0.0017 (11) | −0.0043 (10) |
C12 | 0.0635 (14) | 0.0556 (13) | 0.0598 (14) | −0.0088 (12) | 0.0120 (11) | −0.0206 (11) |
C21 | 0.0556 (14) | 0.0485 (12) | 0.0570 (13) | 0.0019 (11) | 0.0035 (11) | 0.0021 (10) |
C17 | 0.0562 (14) | 0.0657 (15) | 0.0415 (12) | −0.0107 (12) | −0.0004 (10) | −0.0032 (10) |
C14 | 0.0668 (14) | 0.0495 (13) | 0.0489 (12) | 0.0003 (11) | 0.0010 (10) | −0.0028 (10) |
C10 | 0.0710 (16) | 0.0594 (15) | 0.0756 (16) | −0.0146 (13) | −0.0001 (13) | −0.0084 (12) |
C15 | 0.0799 (16) | 0.0440 (13) | 0.0652 (16) | −0.0016 (11) | 0.0100 (12) | −0.0072 (11) |
C25 | 0.0738 (16) | 0.0669 (15) | 0.0450 (13) | 0.0119 (12) | 0.0022 (12) | 0.0003 (11) |
C11 | 0.0676 (16) | 0.0796 (18) | 0.0773 (17) | −0.0176 (14) | 0.0215 (13) | −0.0225 (13) |
C05 | 0.0956 (19) | 0.0776 (17) | 0.0516 (15) | 0.0176 (15) | −0.0130 (13) | −0.0047 (13) |
C23 | 0.104 (2) | 0.0628 (16) | 0.0711 (18) | −0.0159 (16) | 0.0310 (16) | 0.0013 (13) |
C24 | 0.115 (2) | 0.0651 (16) | 0.0469 (14) | 0.0034 (16) | 0.0094 (15) | 0.0031 (11) |
C22 | 0.0689 (16) | 0.0568 (15) | 0.0813 (18) | −0.0066 (12) | 0.0123 (13) | −0.0017 (13) |
C02 | 0.0753 (18) | 0.102 (2) | 0.0663 (17) | −0.0172 (15) | 0.0003 (13) | 0.0206 (15) |
C04 | 0.139 (3) | 0.081 (2) | 0.0523 (16) | 0.018 (2) | 0.0120 (17) | 0.0174 (14) |
C03 | 0.111 (2) | 0.106 (2) | 0.082 (2) | −0.0147 (19) | 0.0172 (18) | 0.0330 (17) |
P—C01 | 1.829 (2) | C06—H06 | 0.93 |
P—C07 | 1.830 (2) | C12—C11 | 1.376 (3) |
P—C13 | 1.8378 (19) | C12—H12 | 0.93 |
N—C20 | 1.383 (2) | C21—C22 | 1.372 (3) |
N—C19 | 1.450 (2) | C21—H21 | 0.93 |
N—H1 | 0.87 (2) | C17—H17 | 0.93 |
C13—C14 | 1.385 (3) | C14—C15 | 1.378 (3) |
C13—C18 | 1.406 (2) | C14—H14 | 0.93 |
C01—C02 | 1.378 (3) | C10—C11 | 1.377 (3) |
C01—C06 | 1.380 (3) | C10—H10 | 0.93 |
C18—C17 | 1.387 (2) | C15—H15 | 0.93 |
C18—C19 | 1.514 (3) | C25—C24 | 1.374 (3) |
C07—C12 | 1.383 (3) | C25—H25 | 0.93 |
C07—C08 | 1.392 (2) | C11—H11 | 0.93 |
C08—C09 | 1.382 (3) | C05—C04 | 1.363 (3) |
C08—H08 | 0.93 | C05—H05 | 0.93 |
C20—C21 | 1.385 (3) | C23—C24 | 1.374 (3) |
C20—C25 | 1.394 (3) | C23—C22 | 1.374 (3) |
C16—C15 | 1.376 (3) | C23—H23 | 0.93 |
C16—C17 | 1.384 (3) | C24—H24 | 0.93 |
C16—H16 | 0.93 | C22—H22 | 0.93 |
C09—C10 | 1.361 (3) | C02—C03 | 1.379 (3) |
C09—H09 | 0.93 | C02—H02 | 0.93 |
C19—H19A | 0.97 | C04—C03 | 1.354 (4) |
C19—H19B | 0.97 | C04—H04 | 0.93 |
C06—C05 | 1.389 (3) | C03—H03 | 0.93 |
C01—P—C07 | 101.66 (9) | C22—C21—C20 | 120.9 (2) |
C01—P—C13 | 102.61 (9) | C22—C21—H21 | 119.5 |
C07—P—C13 | 102.09 (8) | C20—C21—H21 | 119.5 |
C20—N—C19 | 121.23 (18) | C16—C17—C18 | 121.81 (18) |
C20—N—H1 | 114.1 (14) | C16—C17—H17 | 119.1 |
C19—N—H1 | 116.8 (14) | C18—C17—H17 | 119.1 |
C14—C13—C18 | 118.50 (17) | C15—C14—C13 | 122.05 (19) |
C14—C13—P | 122.75 (14) | C15—C14—H14 | 119 |
C18—C13—P | 118.67 (14) | C13—C14—H14 | 119 |
C02—C01—C06 | 117.17 (19) | C09—C10—C11 | 119.6 (2) |
C02—C01—P | 117.87 (17) | C09—C10—H10 | 120.2 |
C06—C01—P | 124.85 (16) | C11—C10—H10 | 120.2 |
C17—C18—C13 | 118.75 (18) | C16—C15—C14 | 119.6 (2) |
C17—C18—C19 | 120.93 (17) | C16—C15—H15 | 120.2 |
C13—C18—C19 | 120.32 (16) | C14—C15—H15 | 120.2 |
C12—C07—C08 | 117.28 (18) | C24—C25—C20 | 120.2 (2) |
C12—C07—P | 125.10 (15) | C24—C25—H25 | 119.9 |
C08—C07—P | 117.61 (15) | C20—C25—H25 | 119.9 |
C09—C08—C07 | 121.01 (19) | C12—C11—C10 | 120.0 (2) |
C09—C08—H08 | 119.5 | C12—C11—H11 | 120 |
C07—C08—H08 | 119.5 | C10—C11—H11 | 120 |
N—C20—C21 | 122.49 (18) | C04—C05—C06 | 120.3 (2) |
N—C20—C25 | 119.36 (19) | C04—C05—H05 | 119.9 |
C21—C20—C25 | 118.15 (19) | C06—C05—H05 | 119.9 |
C15—C16—C17 | 119.23 (18) | C24—C23—C22 | 118.8 (2) |
C15—C16—H16 | 120.4 | C24—C23—H23 | 120.6 |
C17—C16—H16 | 120.4 | C22—C23—H23 | 120.6 |
C10—C09—C08 | 120.5 (2) | C25—C24—C23 | 121.2 (2) |
C10—C09—H09 | 119.7 | C25—C24—H24 | 119.4 |
C08—C09—H09 | 119.7 | C23—C24—H24 | 119.4 |
N—C19—C18 | 114.94 (16) | C21—C22—C23 | 120.8 (2) |
N—C19—H19A | 108.5 | C21—C22—H22 | 119.6 |
C18—C19—H19A | 108.5 | C23—C22—H22 | 119.6 |
N—C19—H19B | 108.5 | C01—C02—C03 | 121.6 (2) |
C18—C19—H19B | 108.5 | C01—C02—H02 | 119.2 |
H19A—C19—H19B | 107.5 | C03—C02—H02 | 119.2 |
C01—C06—C05 | 121.0 (2) | C03—C04—C05 | 119.6 (2) |
C01—C06—H06 | 119.5 | C03—C04—H04 | 120.2 |
C05—C06—H06 | 119.5 | C05—C04—H04 | 120.2 |
C11—C12—C07 | 121.56 (19) | C04—C03—C02 | 120.4 (3) |
C11—C12—H12 | 119.2 | C04—C03—H03 | 119.8 |
C07—C12—H12 | 119.2 | C02—C03—H03 | 119.8 |
C01—P—C13—C14 | −4.49 (18) | C08—C07—C12—C11 | −0.2 (3) |
C07—P—C13—C14 | 100.56 (17) | P—C07—C12—C11 | −179.30 (16) |
C01—P—C13—C18 | 172.24 (15) | N—C20—C21—C22 | 179.95 (19) |
C07—P—C13—C18 | −82.71 (15) | C25—C20—C21—C22 | 0.3 (3) |
C07—P—C01—C02 | 168.20 (17) | C15—C16—C17—C18 | −0.9 (3) |
C13—P—C01—C02 | −86.41 (18) | C13—C18—C17—C16 | 1.1 (3) |
C07—P—C01—C06 | −8.05 (19) | C19—C18—C17—C16 | −178.52 (18) |
C13—P—C01—C06 | 97.34 (18) | C18—C13—C14—C15 | 0.5 (3) |
C14—C13—C18—C17 | −0.9 (3) | P—C13—C14—C15 | 177.21 (15) |
P—C13—C18—C17 | −177.77 (14) | C08—C09—C10—C11 | −0.7 (3) |
C14—C13—C18—C19 | 178.73 (17) | C17—C16—C15—C14 | 0.4 (3) |
P—C13—C18—C19 | 1.9 (2) | C13—C14—C15—C16 | −0.2 (3) |
C01—P—C07—C12 | 90.71 (17) | N—C20—C25—C24 | 179.75 (19) |
C13—P—C07—C12 | −15.08 (18) | C21—C20—C25—C24 | −0.6 (3) |
C01—P—C07—C08 | −88.35 (15) | C07—C12—C11—C10 | 0.3 (3) |
C13—P—C07—C08 | 165.86 (14) | C09—C10—C11—C12 | 0.2 (3) |
C12—C07—C08—C09 | −0.2 (3) | C01—C06—C05—C04 | 0.2 (3) |
P—C07—C08—C09 | 178.89 (15) | C20—C25—C24—C23 | 0.5 (3) |
C19—N—C20—C21 | 15.0 (3) | C22—C23—C24—C25 | 0.0 (4) |
C19—N—C20—C25 | −165.43 (18) | C20—C21—C22—C23 | 0.1 (3) |
C07—C08—C09—C10 | 0.7 (3) | C24—C23—C22—C21 | −0.3 (3) |
C20—N—C19—C18 | −83.4 (2) | C06—C01—C02—C03 | −1.2 (3) |
C17—C18—C19—N | −9.0 (3) | P—C01—C02—C03 | −177.7 (2) |
C13—C18—C19—N | 171.35 (17) | C06—C05—C04—C03 | 0.0 (4) |
C02—C01—C06—C05 | 0.4 (3) | C05—C04—C03—C02 | −0.8 (4) |
P—C01—C06—C05 | 176.66 (15) | C01—C02—C03—C04 | 1.4 (4) |
C26H24NP | F(000) = 1616 |
Mr = 381.43 | Dx = 1.19 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C2yc | Cell parameters from 920 reflections |
a = 23.518 (5) Å | θ = 2.7–21.3° |
b = 8.2811 (17) Å | µ = 0.14 mm−1 |
c = 21.892 (4) Å | T = 293 K |
β = 93.04 (3)° | Cuboid, colourless |
V = 4257.6 (15) Å3 | 0.34 × 0.24 × 0.12 mm |
Z = 8 |
Bruker SMART 1K CCD area-detector diffractometer | 2474 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.051 |
ω scans | θmax = 28.3°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | h = −28→31 |
Tmin = 0.94, Tmax = 0.97 | k = −10→10 |
14295 measured reflections | l = −29→26 |
5216 independent reflections |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.046 | w = 1/[σ2(Fo2) + (0.0494P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.114 | (Δ/σ)max < 0.001 |
S = 0.91 | Δρmax = 0.18 e Å−3 |
5216 reflections | Δρmin = −0.16 e Å−3 |
253 parameters |
C26H24NP | V = 4257.6 (15) Å3 |
Mr = 381.43 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 23.518 (5) Å | µ = 0.14 mm−1 |
b = 8.2811 (17) Å | T = 293 K |
c = 21.892 (4) Å | 0.34 × 0.24 × 0.12 mm |
β = 93.04 (3)° |
Bruker SMART 1K CCD area-detector diffractometer | 5216 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 2474 reflections with I > 2σ(I) |
Tmin = 0.94, Tmax = 0.97 | Rint = 0.051 |
14295 measured reflections |
R[F2 > 2σ(F2)] = 0.046 | 0 restraints |
wR(F2) = 0.114 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.91 | Δρmax = 0.18 e Å−3 |
5216 reflections | Δρmin = −0.16 e Å−3 |
253 parameters |
Experimental. The intensity data for II were collected on a Siemens SMART CCD 1 K diffractometer using an exposure time of 15 s/frame. A total of 1350 frames were collected with a frame width of 0.2° covering up to θ = 28.29° with 98.6% completeness accomplished. The first 50 frames were recollected at the end of each data collection to check for decay; none was found. |
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. |
x | y | z | Uiso*/Ueq | ||
P | 0.09810 (2) | 0.21681 (6) | 0.11595 (2) | 0.05015 (17) | |
N | 0.03980 (7) | 0.3683 (2) | −0.07439 (7) | 0.0652 (5) | |
C13 | 0.10333 (8) | 0.0879 (2) | 0.04803 (8) | 0.0462 (5) | |
C01 | 0.12048 (9) | 0.0810 (2) | 0.17833 (8) | 0.0518 (5) | |
C18 | 0.08039 (8) | 0.1442 (2) | −0.00838 (8) | 0.0503 (5) | |
C07 | 0.15945 (8) | 0.3510 (2) | 0.10992 (8) | 0.0460 (5) | |
C08 | 0.15974 (9) | 0.4958 (2) | 0.14176 (8) | 0.0533 (5) | |
H08 | 0.1297 | 0.5194 | 0.1663 | 0.064* | |
C20 | 0.07878 (9) | 0.4437 (2) | −0.10932 (9) | 0.0528 (5) | |
C16 | 0.10364 (9) | −0.1089 (3) | −0.05497 (10) | 0.0677 (6) | |
H16 | 0.103 | −0.175 | −0.0893 | 0.081* | |
C09 | 0.20329 (10) | 0.6054 (3) | 0.13800 (10) | 0.0673 (6) | |
H09 | 0.2027 | 0.7014 | 0.16 | 0.081* | |
C19 | 0.05499 (9) | 0.3129 (2) | −0.01321 (9) | 0.0643 (6) | |
H19A | 0.0212 | 0.3156 | 0.0103 | 0.077* | |
H19B | 0.0821 | 0.3884 | 0.0056 | 0.077* | |
C06 | 0.17545 (10) | 0.0628 (2) | 0.20217 (9) | 0.0630 (6) | |
H06 | 0.2047 | 0.1212 | 0.1857 | 0.076* | |
C12 | 0.20506 (9) | 0.3209 (3) | 0.07388 (9) | 0.0650 (6) | |
H12 | 0.2062 | 0.2249 | 0.0519 | 0.078* | |
C21 | 0.13646 (10) | 0.4449 (2) | −0.09216 (10) | 0.0643 (6) | |
H21 | 0.1492 | 0.393 | −0.0563 | 0.077* | |
C17 | 0.08115 (9) | 0.0444 (3) | −0.05906 (9) | 0.0626 (6) | |
H17 | 0.0662 | 0.0817 | −0.0966 | 0.075* | |
C14 | 0.12681 (9) | −0.0661 (2) | 0.05078 (9) | 0.0574 (5) | |
H14 | 0.1427 | −0.104 | 0.0878 | 0.069* | |
C10 | 0.24773 (10) | 0.5729 (3) | 0.10169 (10) | 0.0724 (6) | |
H10 | 0.277 | 0.6474 | 0.0986 | 0.087* | |
C15 | 0.12704 (9) | −0.1641 (2) | −0.00008 (10) | 0.0658 (6) | |
H15 | 0.1429 | −0.2668 | 0.0027 | 0.079* | |
C25 | 0.06209 (11) | 0.5213 (2) | −0.16366 (9) | 0.0701 (6) | |
H25 | 0.0239 | 0.5222 | −0.177 | 0.084* | |
C11 | 0.24871 (10) | 0.4306 (3) | 0.07012 (10) | 0.0767 (7) | |
H11 | 0.2791 | 0.4077 | 0.046 | 0.092* | |
C05 | 0.18763 (12) | −0.0429 (3) | 0.25105 (10) | 0.0790 (7) | |
H05 | 0.2248 | −0.0542 | 0.2673 | 0.095* | |
C23 | 0.15791 (16) | 0.5973 (3) | −0.18021 (15) | 0.1027 (10) | |
H23 | 0.1842 | 0.6487 | −0.2039 | 0.123* | |
C24 | 0.10185 (15) | 0.5969 (3) | −0.19793 (11) | 0.0930 (9) | |
H24 | 0.0899 | 0.6488 | −0.234 | 0.112* | |
C22 | 0.17524 (11) | 0.5215 (3) | −0.12733 (14) | 0.0852 (8) | |
H22 | 0.2136 | 0.5214 | −0.1148 | 0.102* | |
C02 | 0.07793 (10) | −0.0073 (3) | 0.20446 (9) | 0.0725 (6) | |
H02 | 0.0404 | 0.0051 | 0.1895 | 0.087* | |
C04 | 0.14409 (15) | −0.1301 (3) | 0.27490 (11) | 0.0919 (9) | |
H04 | 0.152 | −0.2014 | 0.307 | 0.11* | |
C03 | 0.08997 (14) | −0.1128 (3) | 0.25192 (11) | 0.0938 (9) | |
H03 | 0.0608 | −0.1722 | 0.2682 | 0.113* | |
C26 | −0.01834 (10) | 0.3486 (3) | −0.09676 (11) | 0.0848 (7) | |
H26A | −0.0393 | 0.294 | −0.0665 | 0.127* | |
H26B | −0.0195 | 0.286 | −0.1337 | 0.127* | |
H26C | −0.035 | 0.4527 | −0.105 | 0.127* |
U11 | U22 | U33 | U12 | U13 | U23 | |
P | 0.0587 (3) | 0.0464 (3) | 0.0461 (3) | −0.0004 (3) | 0.0094 (2) | −0.0015 (2) |
N | 0.0539 (12) | 0.0811 (13) | 0.0601 (11) | −0.0028 (10) | −0.0023 (9) | 0.0221 (10) |
C13 | 0.0513 (12) | 0.0425 (11) | 0.0452 (11) | −0.0089 (9) | 0.0065 (9) | −0.0007 (9) |
C01 | 0.0681 (14) | 0.0453 (11) | 0.0426 (11) | −0.0039 (11) | 0.0081 (11) | −0.0047 (9) |
C18 | 0.0558 (13) | 0.0498 (12) | 0.0460 (12) | −0.0087 (10) | 0.0086 (9) | 0.0004 (10) |
C07 | 0.0586 (13) | 0.0374 (10) | 0.0422 (10) | 0.0033 (9) | 0.0042 (9) | −0.0007 (9) |
C08 | 0.0598 (14) | 0.0484 (13) | 0.0515 (12) | 0.0067 (10) | 0.0006 (10) | −0.0040 (10) |
C20 | 0.0647 (15) | 0.0436 (11) | 0.0504 (12) | 0.0006 (10) | 0.0038 (11) | −0.0004 (9) |
C16 | 0.0845 (17) | 0.0612 (16) | 0.0581 (14) | −0.0158 (13) | 0.0105 (12) | −0.0191 (11) |
C09 | 0.0762 (16) | 0.0485 (13) | 0.0757 (16) | −0.0024 (12) | −0.0092 (13) | −0.0129 (11) |
C19 | 0.0701 (15) | 0.0670 (15) | 0.0566 (13) | 0.0095 (12) | 0.0111 (11) | 0.0100 (11) |
C06 | 0.0800 (17) | 0.0580 (14) | 0.0514 (12) | −0.0016 (12) | 0.0064 (12) | −0.0024 (10) |
C12 | 0.0719 (15) | 0.0578 (14) | 0.0667 (14) | −0.0110 (12) | 0.0177 (12) | −0.0204 (11) |
C21 | 0.0689 (16) | 0.0515 (13) | 0.0727 (15) | −0.0024 (12) | 0.0061 (13) | −0.0033 (11) |
C17 | 0.0746 (15) | 0.0659 (15) | 0.0471 (12) | −0.0074 (12) | 0.0015 (11) | −0.0025 (11) |
C14 | 0.0736 (15) | 0.0478 (12) | 0.0512 (12) | −0.0041 (11) | 0.0058 (10) | 0.0002 (10) |
C10 | 0.0765 (17) | 0.0631 (15) | 0.0770 (16) | −0.0227 (13) | −0.0008 (13) | −0.0031 (12) |
C15 | 0.0895 (17) | 0.0422 (12) | 0.0670 (15) | −0.0050 (11) | 0.0167 (12) | −0.0067 (11) |
C25 | 0.0979 (18) | 0.0603 (14) | 0.0520 (13) | 0.0022 (13) | 0.0027 (13) | 0.0025 (11) |
C11 | 0.0764 (17) | 0.0832 (17) | 0.0727 (15) | −0.0238 (14) | 0.0253 (13) | −0.0205 (13) |
C05 | 0.101 (2) | 0.0779 (17) | 0.0570 (14) | 0.0130 (15) | −0.0099 (14) | −0.0058 (13) |
C23 | 0.139 (3) | 0.0707 (19) | 0.104 (2) | −0.019 (2) | 0.059 (2) | −0.0058 (17) |
C24 | 0.152 (3) | 0.0720 (18) | 0.0573 (16) | −0.003 (2) | 0.0266 (19) | 0.0070 (12) |
C22 | 0.0779 (18) | 0.0636 (16) | 0.117 (2) | −0.0139 (14) | 0.0294 (17) | −0.0180 (16) |
C02 | 0.0831 (17) | 0.0751 (16) | 0.0597 (14) | −0.0140 (13) | 0.0076 (13) | 0.0076 (12) |
C04 | 0.148 (3) | 0.0734 (18) | 0.0551 (15) | 0.0068 (19) | 0.0095 (18) | 0.0149 (13) |
C03 | 0.123 (3) | 0.089 (2) | 0.0710 (17) | −0.0214 (18) | 0.0143 (17) | 0.0227 (15) |
C26 | 0.0682 (17) | 0.0958 (18) | 0.0897 (17) | −0.0094 (14) | −0.0019 (13) | 0.0020 (15) |
P—C01 | 1.825 (2) | C12—H12 | 0.93 |
P—C07 | 1.832 (2) | C21—C22 | 1.379 (3) |
P—C13 | 1.8400 (18) | C21—H21 | 0.93 |
N—C20 | 1.375 (2) | C17—H17 | 0.93 |
N—C26 | 1.437 (3) | C14—C15 | 1.378 (3) |
N—C19 | 1.443 (2) | C14—H14 | 0.93 |
C13—C14 | 1.390 (3) | C10—C11 | 1.367 (3) |
C13—C18 | 1.401 (2) | C10—H10 | 0.93 |
C01—C06 | 1.377 (3) | C15—H15 | 0.93 |
C01—C02 | 1.387 (3) | C25—C24 | 1.380 (3) |
C18—C17 | 1.384 (2) | C25—H25 | 0.93 |
C18—C19 | 1.521 (3) | C11—H11 | 0.93 |
C07—C08 | 1.387 (2) | C05—C04 | 1.378 (3) |
C07—C12 | 1.387 (3) | C05—H05 | 0.93 |
C08—C09 | 1.374 (3) | C23—C24 | 1.354 (4) |
C08—H08 | 0.93 | C23—C22 | 1.360 (4) |
C20—C21 | 1.388 (3) | C23—H23 | 0.93 |
C20—C25 | 1.390 (3) | C24—H24 | 0.93 |
C16—C15 | 1.373 (3) | C22—H22 | 0.93 |
C16—C17 | 1.376 (3) | C02—C03 | 1.375 (3) |
C16—H16 | 0.93 | C02—H02 | 0.93 |
C09—C10 | 1.373 (3) | C04—C03 | 1.351 (3) |
C09—H09 | 0.93 | C04—H04 | 0.93 |
C19—H19A | 0.97 | C03—H03 | 0.93 |
C19—H19B | 0.97 | C26—H26A | 0.96 |
C06—C05 | 1.401 (3) | C26—H26B | 0.96 |
C06—H06 | 0.93 | C26—H26C | 0.96 |
C12—C11 | 1.377 (3) | ||
C01—P—C07 | 103.35 (9) | C16—C17—C18 | 121.32 (19) |
C01—P—C13 | 102.60 (9) | C16—C17—H17 | 119.3 |
C07—P—C13 | 101.96 (8) | C18—C17—H17 | 119.3 |
C20—N—C26 | 120.83 (17) | C15—C14—C13 | 121.58 (19) |
C20—N—C19 | 121.42 (17) | C15—C14—H14 | 119.2 |
C26—N—C19 | 117.69 (18) | C13—C14—H14 | 119.2 |
C14—C13—C18 | 118.51 (17) | C11—C10—C09 | 119.7 (2) |
C14—C13—P | 122.74 (14) | C11—C10—H10 | 120.2 |
C18—C13—P | 118.68 (14) | C09—C10—H10 | 120.2 |
C06—C01—C02 | 118.00 (19) | C16—C15—C14 | 119.5 (2) |
C06—C01—P | 125.37 (16) | C16—C15—H15 | 120.2 |
C02—C01—P | 116.60 (17) | C14—C15—H15 | 120.2 |
C17—C18—C13 | 119.14 (18) | C24—C25—C20 | 120.4 (2) |
C17—C18—C19 | 120.95 (18) | C24—C25—H25 | 119.8 |
C13—C18—C19 | 119.91 (16) | C20—C25—H25 | 119.8 |
C08—C07—C12 | 117.26 (18) | C10—C11—C12 | 120.4 (2) |
C08—C07—P | 118.12 (15) | C10—C11—H11 | 119.8 |
C12—C07—P | 124.58 (15) | C12—C11—H11 | 119.8 |
C09—C08—C07 | 121.65 (19) | C04—C05—C06 | 119.4 (2) |
C09—C08—H08 | 119.2 | C04—C05—H05 | 120.3 |
C07—C08—H08 | 119.2 | C06—C05—H05 | 120.3 |
N—C20—C21 | 121.56 (18) | C24—C23—C22 | 119.1 (3) |
N—C20—C25 | 121.3 (2) | C24—C23—H23 | 120.5 |
C21—C20—C25 | 117.1 (2) | C22—C23—H23 | 120.5 |
C15—C16—C17 | 119.91 (19) | C23—C24—C25 | 121.5 (3) |
C15—C16—H16 | 120 | C23—C24—H24 | 119.2 |
C17—C16—H16 | 120 | C25—C24—H24 | 119.2 |
C10—C09—C08 | 119.9 (2) | C23—C22—C21 | 120.7 (3) |
C10—C09—H09 | 120.1 | C23—C22—H22 | 119.7 |
C08—C09—H09 | 120.1 | C21—C22—H22 | 119.7 |
N—C19—C18 | 115.71 (17) | C03—C02—C01 | 121.5 (2) |
N—C19—H19A | 108.4 | C03—C02—H02 | 119.3 |
C18—C19—H19A | 108.4 | C01—C02—H02 | 119.3 |
N—C19—H19B | 108.4 | C03—C04—C05 | 120.5 (2) |
C18—C19—H19B | 108.4 | C03—C04—H04 | 119.8 |
H19A—C19—H19B | 107.4 | C05—C04—H04 | 119.8 |
C01—C06—C05 | 120.5 (2) | C04—C03—C02 | 120.1 (3) |
C01—C06—H06 | 119.7 | C04—C03—H03 | 120 |
C05—C06—H06 | 119.7 | C02—C03—H03 | 120 |
C11—C12—C07 | 121.12 (19) | N—C26—H26A | 109.5 |
C11—C12—H12 | 119.4 | N—C26—H26B | 109.5 |
C07—C12—H12 | 119.4 | H26A—C26—H26B | 109.5 |
C22—C21—C20 | 121.2 (2) | N—C26—H26C | 109.5 |
C22—C21—H21 | 119.4 | H26A—C26—H26C | 109.5 |
C20—C21—H21 | 119.4 | H26B—C26—H26C | 109.5 |
C01—P—C13—C14 | −7.36 (18) | P—C01—C06—C05 | 178.69 (15) |
C07—P—C13—C14 | 99.44 (16) | C08—C07—C12—C11 | 0.1 (3) |
C01—P—C13—C18 | 169.70 (15) | P—C07—C12—C11 | 177.69 (17) |
C07—P—C13—C18 | −83.50 (15) | N—C20—C21—C22 | −179.69 (19) |
C07—P—C01—C06 | −14.65 (19) | C25—C20—C21—C22 | 0.7 (3) |
C13—P—C01—C06 | 91.09 (18) | C15—C16—C17—C18 | −1.4 (3) |
C07—P—C01—C02 | 163.58 (15) | C13—C18—C17—C16 | 0.4 (3) |
C13—P—C01—C02 | −90.68 (16) | C19—C18—C17—C16 | −179.45 (19) |
C14—C13—C18—C17 | 0.9 (3) | C18—C13—C14—C15 | −1.1 (3) |
P—C13—C18—C17 | −176.29 (15) | P—C13—C14—C15 | 175.94 (15) |
C14—C13—C18—C19 | −179.28 (17) | C08—C09—C10—C11 | −0.9 (3) |
P—C13—C18—C19 | 3.5 (2) | C17—C16—C15—C14 | 1.2 (3) |
C01—P—C07—C08 | −93.64 (15) | C13—C14—C15—C16 | 0.1 (3) |
C13—P—C07—C08 | 160.13 (15) | N—C20—C25—C24 | 179.7 (2) |
C01—P—C07—C12 | 88.77 (18) | C21—C20—C25—C24 | −0.7 (3) |
C13—P—C07—C12 | −17.45 (19) | C09—C10—C11—C12 | 0.9 (4) |
C12—C07—C08—C09 | −0.1 (3) | C07—C12—C11—C10 | −0.5 (4) |
P—C07—C08—C09 | −177.82 (15) | C01—C06—C05—C04 | 0.5 (3) |
C26—N—C20—C21 | −171.3 (2) | C22—C23—C24—C25 | −0.1 (4) |
C19—N—C20—C21 | 11.6 (3) | C20—C25—C24—C23 | 0.4 (4) |
C26—N—C20—C25 | 8.3 (3) | C24—C23—C22—C21 | 0.2 (4) |
C19—N—C20—C25 | −168.86 (18) | C20—C21—C22—C23 | −0.5 (3) |
C07—C08—C09—C10 | 0.4 (3) | C06—C01—C02—C03 | −1.4 (3) |
C20—N—C19—C18 | −86.9 (2) | P—C01—C02—C03 | −179.73 (18) |
C26—N—C19—C18 | 95.8 (2) | C06—C05—C04—C03 | −0.7 (4) |
C17—C18—C19—N | −8.5 (3) | C05—C04—C03—C02 | −0.1 (4) |
C13—C18—C19—N | 171.65 (17) | C01—C02—C03—C04 | 1.2 (4) |
C02—C01—C06—C05 | 0.5 (3) |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | C25H22NP | C26H24NP |
Mr | 367.41 | 381.43 |
Crystal system, space group | Monoclinic, C2/c | Monoclinic, C2/c |
Temperature (K) | 293 | 293 |
a, b, c (Å) | 22.174 (4), 7.9968 (16), 22.519 (5) | 23.518 (5), 8.2811 (17), 21.892 (4) |
β (°) | 94.50 (3) | 93.04 (3) |
V (Å3) | 3980.7 (14) | 4257.6 (15) |
Z | 8 | 8 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.15 | 0.14 |
Crystal size (mm) | 0.38 × 0.24 × 0.04 | 0.34 × 0.24 × 0.12 |
Data collection | ||
Diffractometer | Bruker SMART 1K CCD area-detector diffractometer | Bruker SMART 1K CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1998) | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.95, 0.97 | 0.94, 0.97 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 16110, 4943, 2201 | 14295, 5216, 2474 |
Rint | 0.075 | 0.051 |
(sin θ/λ)max (Å−1) | 0.668 | 0.667 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.103, 0.86 | 0.046, 0.114, 0.91 |
No. of reflections | 4943 | 5216 |
No. of parameters | 248 | 253 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.15, −0.19 | 0.18, −0.16 |
Computer programs: SMART-NT (Bruker, 1998), SAINT-Plus (Bruker, 1999), SAINT-Plus and XPREP (Bruker, 1999), SIR2002 (Burla et al., 2003), SIR2002 (Altomare et al., 2003), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg & Berndt, 2001), WinGX (Farrugia, 1999).
P—C01 | 1.829 (2) | N—C20 | 1.383 (2) |
P—C07 | 1.830 (2) | N—C19 | 1.450 (2) |
P—C13 | 1.8378 (19) | ||
C01—P—C07 | 101.66 (9) | C07—P—C13 | 102.09 (8) |
C01—P—C13 | 102.61 (9) | C20—N—C19 | 121.23 (18) |
C20—N—C19—C18 | −83.4 (2) |
P—C01 | 1.825 (2) | N—C20 | 1.375 (2) |
P—C07 | 1.832 (2) | N—C26 | 1.437 (3) |
P—C13 | 1.8400 (18) | N—C19 | 1.443 (2) |
C20—N—C19—C18 | −86.9 (2) |
Part of our interest in exploring catalytic reactions led to the manipulation of multifunctional phosphorus-based ligands for evaluation in well known model systems. Aminophosphines, containing both soft (P) and hard (N) Lewis bases, have the ability to stabilize various oxidation states of metals, generating complexes which exhibit different spectroscopic properties, reactivities and applications. Various examples of palladium(II) aminophosphine complexes showing catalytic behaviour have been reported (Koprowski et al., 2002; Reddy et al., 2002), and have also been shown to have potential radiopharmaceutical applications (Chen et al., 2001). The title phosphines, (I) and (II), respectively, are bidentate, and possess a P—N motif which has the potential to bind soft metal centres strongly via the P atom and weakly via the N atom, allowing for the facile displacement of the chelating N-moiety. This situation is frequently desirable in catalysed reactions, and can lead to enhanced stability in the catalyst without sacrificing kinetic or selectivity parameters. By manipulating the substituents on the phosphine, it can be tailored for specific needs in various fields of catalysis as well as further development for radiopharmaceutical use. We report here the structures of (I) and (II) \sch
Compound (I) (Fig. 1) was synthesized previously by Reddy et al. (2002). Compound (II) (Fig. 2) is the methyl derivative of (I). The two compounds are isomorphous, with individual molecules in the centrosymmetric space group C2/c (Z = 8). The bonds and angles in the two compounds are typical compared with other phosphines. An r.m.s overlay (P coordination sphere, r.m.s error 0.01458 Å) of the two compounds shows remarkable similarities (Fig. 3), differing only at the periphery of the molecules. Further investigation into this is required to check whether different electronic and steric groups can be introduced on the N atom without creating additional effects on packing.
The most widely used method for determining ligand steric behaviour at a metal centre is calculation of the Tolman cone angle (Tolman, 1977), using an M—P bond distance of 2.28 Å, C—H bond distances of 0.97 Å, and a van der Waals radius of 1.2 Å for the H atoms. For (I) and (II), dummy atoms were created 2.28 Å from the P atoms and used for the determination of the theoretical Tolman angles, yielding values of 174° for (I) and 182° for (II). The determined value for (II) is slightly larger, due to the contribution from the methyl group on the N atom. However, this may not be an exact indication of the cone angle when bonded to a metal centre, since some degree of freedom for rotation exists on atom C19 and the N atom. The Tolman cone angle is important mainly for monodentate or mono-coordinated ligands, while in bidentate ligands or ligands bound to a metal in a bidentate mode the bite angle becomes more important. In the present instance, the Tolman cone angles calculated for (I) and (II) will be an important parameter in assessing differences (e.g. in reaction rates or selectivities) observed in catalysed reactions, which can be related to a monodentate mode of binding.
No hydrogen-bonding interaction is observed for the N—H group in (I), which is not uncommon (Cambridge Structural Database, Version 5.25, January 2004; Allen, 2002).