Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101013877/fr1341sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101013877/fr1341Isup2.hkl |
CCDC reference: 175106
For related literature, see: Antipin et al. (1985); Belaj (1996); Bell et al. (2000); Bullen & Tucker (1972); Craig et al. (1987); Moloy & Petersen (1995).
Potassium pyrrolide (0.518 g, 4.93 mmol) was slowly added to a vigorously stirred solution of Cl3P═NAr (0.405 g, 1.643 mmol) in hexanes (45 ml) at 195 K. The mixture was stirred for 30 min at 195 K and was then warmed to room temperature and stirred for an additional 14 h. Filtration yielded a colorless liquid that was reduced to 15 ml and cooled to 238 K. The precipitate was removed by filtration and the filtrate was again reduced in volume and cooled to yield colorless crystals (yield: 0.231 g, 41.5%). 1H NMR (300 MHz, d8-toluene, p.p.m.): δ 6.79 (m, 4H, aryl), 6.67 (m, 6H, pyrrolyl), 6.08 (m, 6H, pyrrolyl); 31P NMR (121 MHz, d8-toluene, p.p.m.): δ -32.4.
H atoms were calculated in idealized isotropic positions [C—H = 0.94 Å and Uiso(H) = 1.2Uiso(C)].
Data collection: P3 Diffractometer Control Program (Siemens, 1990); cell refinement: P3 Diffractometer Control Program; data reduction: P3 Diffractometer Control Program; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997).
Fig. 1. The structure of the title compound with 50% probability displacement ellipsoids and the atom-numbering scheme. |
C18H16FN4P | F(000) = 352 |
Mr = 338.32 | Dx = 1.328 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.6950 (15) Å | Cell parameters from 24 reflections |
b = 14.828 (3) Å | θ = 9–13° |
c = 8.0060 (16) Å | µ = 0.18 mm−1 |
β = 112.11 (3)° | T = 206 K |
V = 846.3 (3) Å3 | Plate, colorless |
Z = 2 | 0.40 × 0.30 × 0.05 mm |
Siemens P3 diffractometer | 1343 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.046 |
Graphite monochromator | θmax = 25.0°, θmin = 2.7° |
ω scans | h = −3→9 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→17 |
Tmin = 0.932, Tmax = 0.991 | l = −9→9 |
2400 measured reflections | 3 standard reflections every 197 reflections |
1572 independent reflections | intensity decay: 1% |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.038 | w = 1/[σ2(Fo2) + (0.0413P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.089 | (Δ/σ)max = 0.001 |
S = 1.10 | Δρmax = 0.24 e Å−3 |
1572 reflections | Δρmin = −0.23 e Å−3 |
218 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.011 (3) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983) |
Secondary atom site location: difference Fourier map | Absolute structure parameter: −0.12 (16) |
C18H16FN4P | V = 846.3 (3) Å3 |
Mr = 338.32 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 7.6950 (15) Å | µ = 0.18 mm−1 |
b = 14.828 (3) Å | T = 206 K |
c = 8.0060 (16) Å | 0.40 × 0.30 × 0.05 mm |
β = 112.11 (3)° |
Siemens P3 diffractometer | 1343 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.046 |
Tmin = 0.932, Tmax = 0.991 | 3 standard reflections every 197 reflections |
2400 measured reflections | intensity decay: 1% |
1572 independent reflections |
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.089 | Δρmax = 0.24 e Å−3 |
S = 1.10 | Δρmin = −0.23 e Å−3 |
1572 reflections | Absolute structure: Flack (1983) |
218 parameters | Absolute structure parameter: −0.12 (16) |
1 restraint |
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. |
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. |
x | y | z | Uiso*/Ueq | ||
P1 | 0.80813 (13) | 0.52138 (7) | 0.32311 (11) | 0.0272 (2) | |
F1 | 1.1997 (3) | 0.5907 (2) | 0.5610 (3) | 0.0585 (8) | |
N1 | 0.8647 (5) | 0.6090 (2) | 0.2598 (5) | 0.0375 (9) | |
C1 | 1.0309 (6) | 0.6524 (3) | 0.2756 (5) | 0.0301 (9) | |
N2 | 0.6143 (5) | 0.4788 (2) | 0.1634 (4) | 0.0352 (8) | |
C2 | 1.1985 (6) | 0.6450 (3) | 0.4234 (6) | 0.0387 (10) | |
N3 | 0.9599 (5) | 0.4351 (2) | 0.3703 (4) | 0.0295 (7) | |
C3 | 1.3597 (6) | 0.6884 (3) | 0.4380 (7) | 0.0466 (11) | |
H3A | 1.4706 | 0.6790 | 0.5393 | 0.056* | |
N4 | 0.7442 (4) | 0.5276 (3) | 0.5005 (3) | 0.0307 (7) | |
C4 | 1.3581 (7) | 0.7459 (3) | 0.3025 (7) | 0.0543 (12) | |
H4A | 1.4675 | 0.7770 | 0.3107 | 0.065* | |
C5 | 1.1928 (7) | 0.7574 (3) | 0.1537 (6) | 0.0488 (12) | |
H5A | 1.1904 | 0.7968 | 0.0608 | 0.059* | |
C6 | 1.0324 (7) | 0.7119 (3) | 0.1406 (6) | 0.0399 (10) | |
H6A | 0.9217 | 0.7209 | 0.0390 | 0.048* | |
C7 | 0.5741 (7) | 0.3886 (3) | 0.1217 (6) | 0.0428 (11) | |
H7A | 0.6570 | 0.3401 | 0.1687 | 0.051* | |
C8 | 0.3947 (7) | 0.3820 (4) | 0.0014 (6) | 0.0557 (14) | |
H8A | 0.3319 | 0.3286 | −0.0512 | 0.067* | |
C9 | 0.3202 (6) | 0.4697 (4) | −0.0300 (6) | 0.0562 (14) | |
H9A | 0.1976 | 0.4850 | −0.1072 | 0.067* | |
C10 | 0.4526 (5) | 0.5281 (4) | 0.0682 (5) | 0.0458 (11) | |
H10A | 0.4388 | 0.5910 | 0.0722 | 0.055* | |
C11 | 0.9916 (6) | 0.3684 (3) | 0.5000 (6) | 0.0355 (9) | |
H11A | 0.9353 | 0.3647 | 0.5856 | 0.043* | |
C12 | 1.1172 (6) | 0.3097 (3) | 0.4816 (6) | 0.0414 (10) | |
H12A | 1.1641 | 0.2580 | 0.5523 | 0.050* | |
C13 | 1.1657 (6) | 0.3396 (3) | 0.3375 (6) | 0.0403 (10) | |
H13A | 1.2501 | 0.3110 | 0.2949 | 0.048* | |
C14 | 1.0706 (6) | 0.4157 (3) | 0.2716 (6) | 0.0362 (10) | |
H14A | 1.0775 | 0.4500 | 0.1755 | 0.043* | |
C15 | 0.8419 (6) | 0.5732 (3) | 0.6622 (5) | 0.0384 (10) | |
H15A | 0.9449 | 0.6119 | 0.6841 | 0.046* | |
C16 | 0.7627 (7) | 0.5519 (3) | 0.7800 (6) | 0.0464 (12) | |
H16A | 0.8006 | 0.5735 | 0.8988 | 0.056* | |
C17 | 0.6130 (7) | 0.4917 (3) | 0.6963 (6) | 0.0442 (11) | |
H17A | 0.5345 | 0.4659 | 0.7492 | 0.053* | |
C18 | 0.6034 (6) | 0.4783 (3) | 0.5283 (5) | 0.0366 (9) | |
H18A | 0.5153 | 0.4414 | 0.4421 | 0.044* |
U11 | U22 | U33 | U12 | U13 | U23 | |
P1 | 0.0224 (5) | 0.0319 (5) | 0.0272 (4) | −0.0011 (5) | 0.0093 (4) | 0.0009 (5) |
F1 | 0.0392 (15) | 0.075 (2) | 0.0531 (15) | −0.0035 (15) | 0.0085 (12) | 0.0259 (15) |
N1 | 0.0308 (19) | 0.038 (2) | 0.0446 (19) | −0.0005 (17) | 0.0156 (16) | 0.0107 (16) |
C1 | 0.028 (2) | 0.028 (2) | 0.036 (2) | 0.0041 (18) | 0.0139 (18) | 0.0031 (16) |
N2 | 0.0286 (17) | 0.046 (2) | 0.0295 (16) | −0.0033 (17) | 0.0095 (14) | −0.0029 (15) |
C2 | 0.036 (2) | 0.037 (2) | 0.043 (2) | 0.000 (2) | 0.015 (2) | 0.0051 (18) |
N3 | 0.0287 (17) | 0.0318 (18) | 0.0315 (16) | 0.0001 (16) | 0.0154 (15) | 0.0033 (15) |
C3 | 0.031 (2) | 0.038 (2) | 0.061 (3) | −0.005 (2) | 0.007 (2) | 0.001 (2) |
N4 | 0.0316 (16) | 0.0325 (17) | 0.0294 (14) | −0.0002 (19) | 0.0132 (12) | −0.0038 (17) |
C4 | 0.041 (3) | 0.044 (3) | 0.084 (3) | −0.007 (2) | 0.030 (3) | 0.003 (3) |
C5 | 0.052 (3) | 0.040 (3) | 0.064 (3) | 0.001 (2) | 0.032 (3) | 0.016 (2) |
C6 | 0.044 (2) | 0.033 (2) | 0.049 (2) | 0.006 (2) | 0.024 (2) | 0.0068 (19) |
C7 | 0.044 (3) | 0.048 (3) | 0.042 (2) | −0.017 (2) | 0.021 (2) | −0.009 (2) |
C8 | 0.049 (3) | 0.077 (4) | 0.043 (3) | −0.031 (3) | 0.020 (2) | −0.021 (3) |
C9 | 0.023 (2) | 0.100 (4) | 0.040 (2) | −0.007 (3) | 0.0056 (19) | −0.006 (3) |
C10 | 0.031 (2) | 0.066 (3) | 0.039 (2) | 0.008 (3) | 0.0103 (17) | −0.002 (3) |
C11 | 0.036 (2) | 0.037 (2) | 0.0367 (19) | 0.002 (2) | 0.0167 (17) | 0.0072 (18) |
C12 | 0.036 (2) | 0.032 (2) | 0.054 (3) | 0.004 (2) | 0.015 (2) | 0.007 (2) |
C13 | 0.032 (2) | 0.037 (2) | 0.056 (3) | 0.000 (2) | 0.021 (2) | −0.009 (2) |
C14 | 0.035 (2) | 0.041 (3) | 0.041 (2) | 0.001 (2) | 0.023 (2) | 0.0016 (19) |
C15 | 0.042 (2) | 0.037 (2) | 0.031 (2) | −0.003 (2) | 0.0084 (18) | −0.0023 (18) |
C16 | 0.057 (3) | 0.054 (3) | 0.031 (2) | 0.006 (2) | 0.020 (2) | −0.0025 (18) |
C17 | 0.054 (3) | 0.042 (2) | 0.049 (2) | 0.004 (2) | 0.034 (2) | 0.003 (2) |
C18 | 0.035 (2) | 0.037 (2) | 0.043 (2) | −0.007 (2) | 0.0212 (19) | −0.0022 (19) |
P1—N1 | 1.517 (3) | C7—C8 | 1.357 (6) |
P1—N4 | 1.671 (3) | C7—H7A | 0.9400 |
P1—N3 | 1.676 (3) | C8—C9 | 1.406 (8) |
P1—N2 | 1.680 (3) | C8—H8A | 0.9400 |
F1—C2 | 1.361 (5) | C9—C10 | 1.343 (7) |
N1—C1 | 1.394 (5) | C9—H9A | 0.9400 |
C1—C2 | 1.388 (6) | C10—H10A | 0.9400 |
C1—C6 | 1.398 (5) | C11—C12 | 1.350 (6) |
N2—C7 | 1.386 (6) | C11—H11A | 0.9400 |
N2—C10 | 1.397 (6) | C12—C13 | 1.411 (6) |
C2—C3 | 1.362 (6) | C12—H12A | 0.9400 |
N3—C11 | 1.388 (5) | C13—C14 | 1.341 (6) |
N3—C14 | 1.393 (5) | C13—H13A | 0.9400 |
C3—C4 | 1.377 (7) | C14—H14A | 0.9400 |
C3—H3A | 0.9400 | C15—C16 | 1.339 (6) |
N4—C18 | 1.392 (5) | C15—H15A | 0.9400 |
N4—C15 | 1.402 (5) | C16—C17 | 1.411 (6) |
C4—C5 | 1.388 (7) | C16—H16A | 0.9400 |
C4—H4A | 0.9400 | C17—C18 | 1.334 (5) |
C5—C6 | 1.376 (6) | C17—H17A | 0.9400 |
C5—H5A | 0.9400 | C18—H18A | 0.9400 |
C6—H6A | 0.9400 | ||
N1—P1—N4 | 116.7 (2) | C8—C7—H7A | 125.8 |
N1—P1—N3 | 117.74 (17) | N2—C7—H7A | 125.8 |
N4—P1—N3 | 104.68 (16) | C7—C8—C9 | 107.3 (5) |
N1—P1—N2 | 110.59 (19) | C7—C8—H8A | 126.3 |
N4—P1—N2 | 101.93 (16) | C9—C8—H8A | 126.3 |
N3—P1—N2 | 103.22 (18) | C10—C9—C8 | 108.9 (4) |
C1—N1—P1 | 137.2 (3) | C10—C9—H9A | 125.6 |
C2—C1—N1 | 124.5 (4) | C8—C9—H9A | 125.6 |
C2—C1—C6 | 115.7 (4) | C9—C10—N2 | 107.8 (5) |
N1—C1—C6 | 119.7 (4) | C9—C10—H10A | 126.1 |
C7—N2—C10 | 107.6 (4) | N2—C10—H10A | 126.1 |
C7—N2—P1 | 126.9 (3) | C12—C11—N3 | 108.0 (4) |
C10—N2—P1 | 124.9 (3) | C12—C11—H11A | 126.0 |
F1—C2—C3 | 118.7 (4) | N3—C11—H11A | 126.0 |
F1—C2—C1 | 117.2 (4) | C11—C12—C13 | 107.9 (4) |
C3—C2—C1 | 124.1 (4) | C11—C12—H12A | 126.1 |
C11—N3—C14 | 107.7 (3) | C13—C12—H12A | 126.1 |
C11—N3—P1 | 128.6 (3) | C14—C13—C12 | 108.3 (4) |
C14—N3—P1 | 123.6 (3) | C14—C13—H13A | 125.9 |
C2—C3—C4 | 119.1 (4) | C12—C13—H13A | 125.9 |
C2—C3—H3A | 120.4 | C13—C14—N3 | 108.1 (4) |
C4—C3—H3A | 120.4 | C13—C14—H14A | 126.0 |
C18—N4—C15 | 106.5 (3) | N3—C14—H14A | 126.0 |
C18—N4—P1 | 127.0 (3) | C16—C15—N4 | 108.0 (4) |
C15—N4—P1 | 125.8 (3) | C16—C15—H15A | 126.0 |
C3—C4—C5 | 119.1 (4) | N4—C15—H15A | 126.0 |
C3—C4—H4A | 120.5 | C15—C16—C17 | 108.8 (4) |
C5—C4—H4A | 120.5 | C15—C16—H16A | 125.6 |
C6—C5—C4 | 120.8 (4) | C17—C16—H16A | 125.6 |
C6—C5—H5A | 119.6 | C18—C17—C16 | 107.4 (4) |
C4—C5—H5A | 119.6 | C18—C17—H17A | 126.3 |
C5—C6—C1 | 121.3 (4) | C16—C17—H17A | 126.3 |
C5—C6—H6A | 119.4 | C17—C18—N4 | 109.4 (4) |
C1—C6—H6A | 119.4 | C17—C18—H18A | 125.3 |
C8—C7—N2 | 108.4 (5) | N4—C18—H18A | 125.3 |
Experimental details
Crystal data | |
Chemical formula | C18H16FN4P |
Mr | 338.32 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 206 |
a, b, c (Å) | 7.6950 (15), 14.828 (3), 8.0060 (16) |
β (°) | 112.11 (3) |
V (Å3) | 846.3 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.18 |
Crystal size (mm) | 0.40 × 0.30 × 0.05 |
Data collection | |
Diffractometer | Siemens P3 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.932, 0.991 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2400, 1572, 1343 |
Rint | 0.046 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.089, 1.10 |
No. of reflections | 1572 |
No. of parameters | 218 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.24, −0.23 |
Absolute structure | Flack (1983) |
Absolute structure parameter | −0.12 (16) |
Computer programs: P3 Diffractometer Control Program (Siemens, 1990), P3 Diffractometer Control Program, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997).
P1—N1 | 1.517 (3) | P1—N2 | 1.680 (3) |
P1—N4 | 1.671 (3) | F1—C2 | 1.361 (5) |
P1—N3 | 1.676 (3) | N1—C1 | 1.394 (5) |
N1—P1—N4 | 116.7 (2) | N4—P1—N2 | 101.93 (16) |
N1—P1—N3 | 117.74 (17) | N3—P1—N2 | 103.22 (18) |
N4—P1—N3 | 104.68 (16) | C1—N1—P1 | 137.2 (3) |
N1—P1—N2 | 110.59 (19) |
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We have recently reported that iminophosphoranes of the type Cl3P═NAr (Ar is 2-fluorophenyl) are important main-group examples of well defined carbodiimide metathesis catalysts (Bell et al., 2000). It is believed that these catalysts follow an addition–elimination pathway for double-bond metathesis. We produced pyrrolyl derivatives of the iminophosphoranes in an effort to rule out the possibility of HCl-mediated metathesis pathways that might arise from the decomposition of trichloroiminophosphoranes. Selection of the pyrrolyl moiety as a chloride replacement was prompted by Petersen's discussion of tripyrrolylphosphorus ligands (Moloy & Petersen, 1995). In particular, pyrrolyl is π-acidic, which allows replacement of chlorine without loss of electrophilicity at the phosphorus center, believed to be an important factor in the carbodiimide metatheses.
The structure determination of the title compound, (I), was undertaken to study the effect of substitution on significant features of the phosphorus center. We report herein the first example of a tripyrrolyl derivative of an iminophosphorane. The only previous example of a pyrrolyl derivative is bispyrrolylcyclophosphazene (Craig et al., 1987). A notable aspect of the crystal structure reported here is the short P═N bond length [1.517 (3) Å], which is significantly shorter than in bispyrrolylcyclophosphazene [1.583 (6) Å]. It is important to note that the P═N bond length is similar to chlorine-derivatized hydrocarbyliminophosphoranes ranging from 1.505 (3) (Antipin et al., 1985) to 1.557 (2) Å (Belaj, 1996).
P—N bond length has been correlated with the orbital electronegativity of the phosphorus substituents (Bullen & Tucker, 1972). The comparable P═N bond length of the trichloro- and tripyrrolyliminophosphoranes indicates a similar electronegativity of the phosphorus substituents.
The P atom is slightly distorted from tetrahedral geometry, with the bond angles around it varying from 101.93 (16) to 117.74 (17)°, the average value being 109.1 (2)°. The pyrrolyl groups make interplanar angles of 45.9 (3), 55.0 (3) and 63.4 (2)° with the 2-fluorophenyl ring. The P atom has chirality due to the propeller-like arrangement of the pyrrolyl rings, although no conclusion can be made about the absolute configuration as the Friedel pairs were not collected for this structure.