2,4-Dioxo-1,3-diazetidine-1,3-bis(methyl-m-phenylene) diisocyanate (dimerized toluene-2,4-diisocyanate, TDI) is one of the most widely used aromatic diisocyanates in the polymer industry, and it crystallizes in at least two polymorphic forms (form A and form B) depending on reaction conditions. The crystal structures of the two forms were determined from high-resolution laboratory X-ray powder diffraction data using simulated annealing and Rietveld refinement. In spite of a marked structural similarity between them, significant discrepancies in the physical properties of the two forms prompted analysis of their partitioned energy terms in an effort to better our understanding of the driving force behind such differences in behaviour.
Supporting information
CCDC references: 879425; 879426
(TDIC01) toluene-2,4-diisocyanate
top
Crystal data top
C18H12N4O4 | β = 81.6029 (15)° |
Mr = 348 | γ = 81.2337 (13)° |
Triclinic, P1 | V = 391.75 (1) Å3 |
a = 4.53125 (8) Å | Z = 1 |
b = 5.99235 (8) Å | Cu Kα radiation, λ = 1.54059 Å |
c = 14.7567 (3) Å | T = 298 K |
α = 88.2562 (12)° | ?, ? × ? × ? mm |
Data collection top
Bruker D8 ADVANCE diffractometer | Scan method: step |
Specimen mounting: Capillary | 2θmin = 5.0°, 2θmax = 68.3°, 2θstep = 0.009° |
Data collection mode: transmission | |
Refinement top
Refinement on F2 | Profile function: Calculated from fundamental parameters |
Rp = 0.036 | 63 parameters |
Rwp = 0.050 | 47 restraints |
Rexp = 0.015 | |
χ2 = NOT FOUND | Background function: Chebychev polynomial |
7362 data points | |
Crystal data top
C18H12N4O4 | β = 81.6029 (15)° |
Mr = 348 | γ = 81.2337 (13)° |
Triclinic, P1 | V = 391.75 (1) Å3 |
a = 4.53125 (8) Å | Z = 1 |
b = 5.99235 (8) Å | Cu Kα radiation, λ = 1.54059 Å |
c = 14.7567 (3) Å | T = 298 K |
α = 88.2562 (12)° | ?, ? × ? × ? mm |
Data collection top
Bruker D8 ADVANCE diffractometer | Scan method: step |
Specimen mounting: Capillary | 2θmin = 5.0°, 2θmax = 68.3°, 2θstep = 0.009° |
Data collection mode: transmission | |
Refinement top
Rp = 0.036 | 7362 data points |
Rwp = 0.050 | 63 parameters |
Rexp = 0.015 | 47 restraints |
χ2 = NOT FOUND | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.3493 (11) | 0.1024 (10) | 1.0115 (4) | 0.04245 | |
N2 | 0.5466 (4) | 0.0707 (5) | 0.9318 (2) | 0.04245 | |
O3 | 0.1186 (8) | 0.2393 (6) | 1.0302 (3) | 0.04245 | |
C5 | 0.6337 (3) | 0.2109 (3) | 0.8649 (1) | 0.04245 | |
C8 | 0.5141 (3) | 0.4354 (3) | 0.8508 (1) | 0.04245 | |
C9 | 0.8690 (3) | 0.1268 (4) | 0.8017 (1) | 0.04245 | |
C13 | 0.6320 (3) | 0.5599 (4) | 0.7764 (1) | 0.04245 | |
H14 | 0.3337 (16) | 0.5084 (12) | 0.8974 (5) | 0.05094 | |
C15 | 1.0001 (2) | 0.2467 (4) | 0.7238 (1) | 0.04245 | |
H16 | 0.9282 (17) | −0.0406 (10) | 0.8224 (5) | 0.05094 | |
C21 | 0.8758 (3) | 0.4810 (4) | 0.7085 (1) | 0.04245 | |
H22 | 0.5375 (17) | 0.7325 (11) | 0.7670 (4) | 0.05094 | |
N23 | 1.2526 (4) | 0.1486 (5) | 0.6586 (2) | 0.04245 | |
C27 | 0.9887 (5) | 0.6274 (5) | 0.6288 (2) | 0.04245 | |
C28 | 1.4796 (14) | 0.2074 (12) | 0.6035 (3) | 0.04245 | |
H31 | 1.1710 (14) | 0.7320 (15) | 0.6186 (2) | 0.05094 | |
H32 | 0.987 (5) | 0.530 (3) | 0.5644 (6) | 0.05094 | |
H33 | 0.773 (2) | 0.731 (2) | 0.6171 (18) | 0.05094 | |
O34 | 1.5660 (11) | 0.2222 (8) | 0.5312 (3) | 0.04245 | |
Geometric parameters (Å, º) top
O3—C1 | 1.229 (7) | C13—C21 | 1.412 (2) |
O34—C28 | 1.087 (6) | C21—C27 | 1.521 (3) |
N2—C5 | 1.332 (3) | C8—H14 | 1.038 (7) |
N23—C28 | 1.301 (6) | C13—H22 | 1.071 (7) |
C5—C8 | 1.393 (2) | C27—H32 | 1.132 (11) |
C5—C9 | 1.355 (2) | C27—H33 | 1.108 (11) |
C8—C13 | 1.396 (2) | | |
| | | |
N2—C5—C8 | 128.46 (17) | C5—C8—H14 | 118.1 (4) |
N2—C5—C9 | 116.62 (19) | C13—C8—H14 | 120.6 (4) |
C8—C5—C9 | 114.92 (16) | C8—C13—H22 | 120.2 (4) |
C5—C8—C13 | 121.35 (15) | C21—C13—H22 | 113.7 (4) |
C8—C13—C21 | 126.1 (2) | C21—C27—H32 | 106.2 (7) |
C13—C21—C27 | 122.9 (2) | C21—C27—H33 | 100.0 (11) |
O34—C28—N23 | 142.1 (6) | H32—C27—H33 | 89.3 (16) |
(TDIC02) toluene-2,4-diisocyanate
top
Crystal data top
C18H12N4O4 | β = 99.7115 (6)° |
Mr = 348 | γ = 114.0050 (6)° |
Triclinic, P1 | V = 770.56 (1) Å3 |
a = 9.09477 (8) Å | Z = 2 |
b = 7.45366 (5) Å | Cu Kα radiation, λ = 1.54059 Å |
c = 12.75989 (16) Å | T = 298 K |
α = 93.5753 (8)° | ?, ? × ? × ? mm |
Data collection top
Bruker D8 ADVANCE diffractometer | Scan method: step |
Specimen mounting: Capillary | 2θmin = 5.0°, 2θmax = 67.4°, 2θstep = 0.009° |
Data collection mode: transmission | |
Refinement top
Refinement on F2 | Profile function: Calculated from fundamental parameters |
Rp = 0.019 | 150 parameters |
Rwp = 0.025 | 104 restraints |
Rexp = 0.012 | |
χ2 = NOT FOUND | Background function: Chebychev polynomial |
7268 data points | |
Crystal data top
C18H12N4O4 | β = 99.7115 (6)° |
Mr = 348 | γ = 114.0050 (6)° |
Triclinic, P1 | V = 770.56 (1) Å3 |
a = 9.09477 (8) Å | Z = 2 |
b = 7.45366 (5) Å | Cu Kα radiation, λ = 1.54059 Å |
c = 12.75989 (16) Å | T = 298 K |
α = 93.5753 (8)° | ?, ? × ? × ? mm |
Data collection top
Bruker D8 ADVANCE diffractometer | Scan method: step |
Specimen mounting: Capillary | 2θmin = 5.0°, 2θmax = 67.4°, 2θstep = 0.009° |
Data collection mode: transmission | |
Refinement top
Rp = 0.019 | 7268 data points |
Rwp = 0.025 | 150 parameters |
Rexp = 0.012 | 104 restraints |
χ2 = NOT FOUND | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.0703 (4) | 0.7858 (7) | 0.3017 (3) | 0.04011 | |
N2 | 0.2307 (4) | 0.8069 (5) | 0.3074 (3) | 0.04011 | |
O3 | −0.0331 (4) | 0.7936 (5) | 0.2318 (3) | 0.04011 | |
N4 | 0.0699 (4) | 0.7589 (5) | 0.4111 (3) | 0.04011 | |
C5 | 0.3247 (4) | 0.8023 (3) | 0.2331 (3) | 0.04011 | |
C6 | 0.2320 (4) | 0.7805 (7) | 0.4170 (3) | 0.04011 | |
C7 | −0.0349 (4) | 0.7428 (4) | 0.4810 (3) | 0.04011 | |
C8 | 0.4932 (4) | 0.8636 (3) | 0.2670 (3) | 0.04011 | |
C9 | 0.2510 (4) | 0.7340 (3) | 0.1275 (3) | 0.04011 | |
O10 | 0.3391 (4) | 0.7768 (5) | 0.4910 (3) | 0.04011 | |
C11 | −0.1903 (4) | 0.7282 (4) | 0.4456 (3) | 0.04011 | |
C12 | 0.0211 (4) | 0.7419 (3) | 0.5860 (3) | 0.04011 | |
C13 | 0.5879 (4) | 0.8557 (3) | 0.1948 (3) | 0.04011 | |
H14 | 0.5511 (14) | 0.9174 (18) | 0.3498 (11) | 0.04813 | |
C15 | 0.3499 (4) | 0.7301 (4) | 0.0555 (3) | 0.04011 | |
H16 | 0.1171 (15) | 0.6822 (18) | 0.0999 (13) | 0.04813 | |
C17 | −0.2898 (4) | 0.7111 (3) | 0.5161 (3) | 0.04011 | |
H18 | −0.2344 (15) | 0.7314 (18) | 0.3619 (12) | 0.04813 | |
C19 | −0.0797 (4) | 0.7254 (4) | 0.6611 (3) | 0.04011 | |
H20 | 0.1474 (15) | 0.7576 (18) | 0.6119 (13) | 0.04813 | |
C21 | 0.5195 (4) | 0.7890 (3) | 0.0876 (3) | 0.04011 | |
H22 | 0.7204 (14) | 0.9077 (18) | 0.2248 (11) | 0.04813 | |
N23 | 0.2597 (4) | 0.6579 (5) | −0.0496 (3) | 0.04011 | |
C24 | −0.2407 (4) | 0.7089 (4) | 0.6270 (3) | 0.04011 | |
H25 | −0.4075 (17) | 0.6980 (18) | 0.4848 (14) | 0.04813 | |
N26 | −0.0092 (5) | 0.7234 (5) | 0.7693 (3) | 0.04011 | |
C27 | 0.6218 (4) | 0.7851 (4) | 0.0097 (3) | 0.04011 | |
C28 | 0.2965 (5) | 0.6435 (7) | −0.1378 (3) | 0.04011 | |
C29 | −0.3540 (4) | 0.6866 (4) | 0.7065 (3) | 0.04011 | |
C30 | −0.0409 (5) | 0.7544 (7) | 0.8574 (3) | 0.04011 | |
H31 | 0.5585 (17) | 0.6578 (17) | −0.0518 (13) | 0.04813 | |
H32 | 0.6552 (14) | 0.9230 (16) | −0.0237 (12) | 0.04813 | |
H33 | 0.7292 (14) | 0.7817 (19) | 0.0511 (14) | 0.04813 | |
O34 | 0.3068 (4) | 0.6249 (5) | −0.2279 (3) | 0.04011 | |
H35 | −0.3927 (16) | 0.5402 (18) | 0.7350 (11) | 0.04813 | |
H36 | −0.2883 (14) | 0.808 (2) | 0.7742 (11) | 0.04813 | |
H37 | −0.4597 (15) | 0.6999 (18) | 0.6664 (12) | 0.04813 | |
O38 | −0.0507 (5) | 0.7736 (5) | 0.9447 (3) | 0.04011 | |
Geometric parameters (Å, º) top
C1—N2 | 1.391 (5) | C13—C21 | 1.372 (5) |
C1—O3 | 1.205 (6) | C13—H22 | 1.093 (14) |
C1—N4 | 1.423 (5) | C15—C21 | 1.398 (5) |
N2—C5 | 1.387 (5) | C15—N23 | 1.393 (5) |
N2—C6 | 1.423 (5) | C17—C24 | 1.413 (5) |
N4—C6 | 1.405 (6) | C17—H25 | 1.040 (17) |
N4—C7 | 1.388 (5) | C19—C24 | 1.407 (5) |
C5—C8 | 1.388 (5) | C19—N26 | 1.425 (5) |
C5—C9 | 1.362 (5) | C21—C27 | 1.478 (5) |
C6—O10 | 1.247 (6) | N23—C28 | 1.238 (6) |
C7—C11 | 1.366 (5) | C24—C29 | 1.534 (5) |
C7—C12 | 1.352 (5) | N26—C30 | 1.238 (6) |
C8—C13 | 1.377 (5) | C27—H31 | 1.076 (15) |
C8—H14 | 1.069 (14) | C27—H32 | 1.084 (12) |
C9—C15 | 1.397 (5) | C27—H33 | 1.040 (16) |
C9—H16 | 1.101 (15) | C28—O34 | 1.173 (5) |
C11—C17 | 1.356 (5) | C29—H35 | 1.108 (13) |
C11—H18 | 1.081 (15) | C29—H36 | 1.100 (14) |
C12—C19 | 1.412 (5) | C29—H37 | 1.055 (15) |
C12—H20 | 1.096 (16) | C30—O38 | 1.137 (5) |
| | | |
C1—N2—C5 | 135.3 (4) | C11—C17—C24 | 123.2 (4) |
C1—N2—C6 | 85.6 (3) | N26—C19—C12 | 116.1 (3) |
C5—N2—C6 | 137.2 (3) | N26—C19—C24 | 123.8 (3) |
C1—N4—C6 | 85.1 (3) | C12—C19—C24 | 120.1 (3) |
C1—N4—C7 | 136.9 (4) | C13—C21—C15 | 116.9 (3) |
C6—N4—C7 | 137.7 (4) | C13—C21—C27 | 121.3 (3) |
C15—N23—C28 | 134.3 (4) | C15—C21—C27 | 121.8 (3) |
C19—N26—C30 | 134.2 (4) | C17—C24—C19 | 115.7 (3) |
O3—C1—N2 | 133.9 (4) | C17—C24—C29 | 123.2 (3) |
O3—C1—N4 | 131.0 (4) | C19—C24—C29 | 121.1 (3) |
N2—C1—N4 | 95.0 (3) | O34—C28—N23 | 169.6 (5) |
N2—C5—C8 | 119.8 (3) | O38—C30—N26 | 168.9 (5) |
N2—C5—C9 | 120.0 (3) | C5—C8—H14 | 120.2 (8) |
C8—C5—C9 | 120.2 (4) | C13—C8—H14 | 119.1 (8) |
O10—C6—N2 | 132.4 (4) | C5—C9—H16 | 120.9 (9) |
O10—C6—N4 | 133.2 (4) | C15—C9—H16 | 121.0 (9) |
N2—C6—N4 | 94.4 (3) | C7—C11—H18 | 120.6 (9) |
N4—C7—C11 | 121.4 (3) | C17—C11—H18 | 119.6 (9) |
N4—C7—C12 | 118.0 (4) | C7—C12—H20 | 118.6 (9) |
C11—C7—C12 | 120.5 (4) | C19—C12—H20 | 120.7 (9) |
C5—C8—C13 | 120.7 (3) | C8—C13—H22 | 118.2 (8) |
C5—C9—C15 | 118.1 (3) | C21—C13—H22 | 120.5 (8) |
C7—C11—C17 | 119.8 (3) | C11—C17—H25 | 116.7 (10) |
C7—C12—C19 | 120.8 (4) | C24—C17—H25 | 120.1 (10) |
C8—C13—C21 | 121.3 (3) | C21—C27—H31 | 111.8 (9) |
N23—C15—C9 | 112.4 (3) | C21—C27—H32 | 107.1 (8) |
N23—C15—C21 | 124.8 (4) | C21—C27—H33 | 108.4 (10) |
C9—C15—C21 | 122.9 (3) | H31—C27—H32 | 111.8 (11) |
H31—C27—H33 | 109.4 (12) | C24—C29—H37 | 107.8 (9) |
H32—C27—H33 | 108.2 (11) | H35—C29—H36 | 111.0 (10) |
C24—C29—H35 | 111.7 (8) | H35—C29—H37 | 108.8 (11) |
C24—C29—H36 | 108.3 (8) | H36—C29—H37 | 109.2 (11) |
Experimental details
| (TDIC01) | (TDIC02) |
Crystal data |
Chemical formula | C18H12N4O4 | C18H12N4O4 |
Mr | 348 | 348 |
Crystal system, space group | Triclinic, P1 | Triclinic, P1 |
Temperature (K) | 298 | 298 |
a, b, c (Å) | 4.53125 (8), 5.99235 (8), 14.7567 (3) | 9.09477 (8), 7.45366 (5), 12.75989 (16) |
α, β, γ (°) | 88.2562 (12), 81.6029 (15), 81.2337 (13) | 93.5753 (8), 99.7115 (6), 114.0050 (6) |
V (Å3) | 391.75 (1) | 770.56 (1) |
Z | 1 | 2 |
Radiation type | Cu Kα, λ = 1.54059 Å | Cu Kα, λ = 1.54059 Å |
µ (mm−1) | ? | ? |
Specimen shape, size (mm) | ?, ? × ? × ? | ?, ? × ? × ? |
|
Data collection |
Diffractometer | Bruker D8 ADVANCE diffractometer | Bruker D8 ADVANCE diffractometer |
Specimen mounting | Capillary | Capillary |
Data collection mode | Transmission | Transmission |
Scan method | Step | Step |
2θ values (°) | 2θmin = 5.0 2θmax = 68.3 2θstep = 0.009 | 2θmin = 5.0 2θmax = 67.4 2θstep = 0.009 |
|
Refinement |
R factors and goodness of fit | Rp = 0.036, Rwp = 0.050, Rexp = 0.015, χ2 = NOT FOUND | Rp = 0.019, Rwp = 0.025, Rexp = 0.012, χ2 = NOT FOUND |
No. of data points | 7362 | 7268 |
No. of parameters | 63 | 150 |
No. of restraints | 47 | 104 |