Supplementary Material For s6

Supplementary Material for:

Internal Rotation of 2-, 3- and 4-Pyridine Carboxaldehydes and their Chalcogen Analogues (S and Se) in the Gas and Solution Phases: A Theoretical Investigation

Hassan H. Abdallah1,2 · P. H. Yeoh2 · L. Rhyman3 · I. A. Alswaidan4 · H.-K. Fun4,5 · Yunusa Umar6 P. Ramasami3,7

1School of Chemistry Department, College of Education, Salahaddin University, Erbil, Iraq

2School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia

3Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius

4Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia

5X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia

6Department of Chemical and Process Engineering Technology, Jubail Industrial College, Saudi Arabia

7Professor Extraordinarius, Department of Chemistry, College of Science, Engineering and Technology, University of South Africa, P.O. Box 392, Pretoria 0003, South Africa

LUMO / HOMO / LUMO / HOMO
Anti 2-PCA / Syn 2-PCA
LUMO / HOMO / LUMO / HOMO
Anti 3-PCA / Syn 3-PCA
LUMO / HOMO
4-PCA

Fig. S1a HOMO and LUMO orbital of 2-, 3-, and 4-pyridine carboxaldehydes (PCA) in Cs symmetry in the gas phase computed using the B3LYP/6-311++G(d,p) method

LUMO / HOMO / LUMO / HOMO
Anti 2-PCS / Syn 2-PCS
LUMO / HOMO / LUMO / HOMO
Anti 3-PCS / Syn 3-PCS
LUMO / HOMO
4-PCS

Fig. S1b HOMO and LUMO orbital of 2-, 3-, and 4-pyridine carbothioaldehyde in Cs symmetry in the gas phase computed using the B3LYP/6-311++G(d,p) method

LUMO / HOMO / LUMO / HOMO
Anti 2-PCSe / Syn 2-PCSe
LUMO / HOMO / LUMO / HOMO
Anti 3-PCSe / Syn 3-PCSe
LUMO / HOMO
4-PCSe

Fig. S1c HOMO and LUMO orbital of 2-, 3-, and 4-pyridine carbothioaldehyde in Cs symmetry in the gas phase computed using the B3LYP/6-311++G(d,p) method

Table S1 Optimized structural parameters of 2-pyridine carboxaldehyde and its sulfur and selenium analogues in the gas phase obtained using the B3LYP/6-311++G(d,p) method

Syn / Transition state / Anti
Bond length (Å)
Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se
r(C1-C2) / 1.400 / 1.401 / 1.401 / 1.393 / 1.393 / 1.393 / 1.396 / 1.396 / 1.397
r(C2-N3) / 1.329 / 1.327 / 1.326 / 1.337 / 1.337 / 1.337 / 1.333 / 1.331 / 1.330
r(N3-C4) / 1.341 / 1.345 / 1.347 / 1.336 / 1.337 / 1.338 / 1.341 / 1.348 / 1.351
r(C4-C5) / 1.397 / 1.404 / 1.406 / 1.395 / 1.398 / 1.399 / 1.397 / 1.402 / 1.404
r(C4-C7) / 1.498 / 1.472 / 1.463 / 1.513 / 1.496 / 1.490 / 1.493 / 1.469 / 1.461
r(C5-C6) / 1.393 / 1.391 / 1.391 / 1.392 / 1.391 / 1.391 / 1.390 / 1.388 / 1.387
r(C6-C1) / 1.389 / 1.389 / 1.389 / 1.392 / 1.392 / 1.392 / 1.493 / 1.393 / 1.393
r(C7-Y8) / 1.204 / 1.627 / 1.772 / 1.203 / 1.619 / 1.761 / 1.209 / 1.632 / 1.777
r(C1-H9) / 1.084 / 1.084 / 1.084 / 1.083 / 1.083 / 1.083 / 1.084 / 1.084 / 1.084
r(C2-H10) / 1.087 / 1.087 / 1.087 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086
r(C5-H11) / 1.085 / 1.084 / 1.084 / 1.084 / 1.084 / 1.083 / 1.083 / 1.083 / 1.083
r(C6-H12) / 1.084 / 1.084 / 1.084 / 1.084 / 1.084 / 1.084 / 1.084 / 1.084 / 1.084
r(C7-H13) / 1.112 / 1.092 / 1.089 / 1.111 / 1.093 / 1.090 / 1.107 / 1.090 / 1.088
Angle (°)
Ð(C1C2N3) / 123.6 / 123.8 / 123.9 / 123.5 / 123.6 / 123.6 / 123.2 / 123.4 / 123.5
Ð (C2N3C4) / 117.5 / 118.0 / 118.1 / 117.4 / 117.6 / 117.7 / 117.6 / 118.0 / 118.1
Ð (N3C4C5) / 123.2 / 122.2 / 122.0 / 123.7 / 123.3 / 123.1 / 123.6 / 122.6 / 122.3
Ð (C4C5C6) / 118.8 / 119.2 / 119.3 / 118.2 / 118.4 / 118.4 / 118.3 / 118.7 / 118.9
Ð (C4C7Y8) / 125.6 / 127.9 / 128.3 / 123.3 / 124.7 / 124.7 / 124.1 / 127.7 / 128.3
Ð (C5C6C1) / 118.3 / 118.4 / 118.5 / 118.8 / 118.9 / 118.9 / 118.6 / 118.8 / 118.8
Ð (C6C1C2) / 118.6 / 118.4 / 118.3 / 118.5 / 118.3 / 118.2 / 118.8 / 118.5 / 118.4
Ð (C7C4N3) / 118.3 / 119.4 / 119.6 / 115.6 / 116.3 / 116.4 / 115.3 / 114.6 / 114.5
Ð (C7C4C5) / 118.6 / 118.4 / 118.5 / 120.7 / 120.5 / 120.5 / 121.1 / 122.9 / 123.3
Ð(Y8C7H13) / 120.9 / 118.9 / 117.8 / 120.9 / 120.0 / 119.2 / 122.3 / 120.1 / 119.0
Ð (C4C7H13) / 113.5 / 113.2 / 114.0 / 115.7 / 115.3 / 116.1 / 113.6 / 112.2 / 112.7
Ð (C1C2H10) / 120.2 / 120.1 / 120.1 / 120.6 / 120.6 / 120.6 / 120.5 / 120.4 / 120.4
Ð(N3C2H10) / 116.2 / 116.1 / 116.1 / 115.9 / 115.8 / 115.8 / 116.3 / 116.2 / 116.1
Ð (C4C5H11) / 120.1 / 120.0 / 120.0 / 120.7 / 120.5 / 120.4 / 119.3 / 119.4 / 119.3
Ð(C6C5H11) / 121.1 / 120.8 / 120.8 / 121.2 / 121.2 / 121.2 / 122.4 / 121.9 / 121.8
Ð (C5C6H12) / 120.8 / 120.7 / 120.6 / 120.5 / 120.4 / 120.3 / 120.7 / 120.5 / 120.5
Ð (C1C6H12) / 120.9 / 120.9 / 120.9 / 120.8 / 120.8 / 120.8 / 120.7 / 120.7 / 120.7
Ð (C6C1H9) / 121.3 / 121.4 / 121.5 / 121.3 / 121.4 / 121.4 / 121.2 / 121.3 / 121.3
Ð (C2C1H9) / 120.1 / 120.2 / 120.3 / 120.3 / 120.4 / 120.4 / 120.1 / 120.2 / 120.2
Rotational constant (GHz)
A / 5.0715 / 4.8473 / 4.7192 / 5.2386 / 4.5602 / 4.3088 / 5.0585 / 4.8236 / 4.6893
B / 1.5103 / 1.0424 / 0.6604 / 1.5289 / 1.0213 / 0.6519 / 1.5231 / 1.0560 / 0.6710
C / 1.1637 / 0.8579 / 0.5793 / 1.2469 / 0.8917 / 0.6011 / 1.1706 / 0.8663 / 0.5870
Dipole moment (Debye)
5.3960 / 4.8776 / 4.6959 / 4.4581 / 3.7204 / 3.4423 / 3.9438 / 3.8133 / 3.7087

Table S2 Optimized structural parameters of 3-pyridine carboxaldehyde and its sulfur and selenium analogues in the gas phase obtained using the B3LYP/6-311++G(d,p) method

Syn / Transition state / Anti
Bond length (Å)
Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se
r(C1-C2) / 1.394 / 1.394 / 1.394 / 1.394 / 1.393 / 1.393 / 1.399 / 1.399 / 1.399
r(C2-N3) / 1.340 / 1.341 / 1.341 / 1.336 / 1.336 / 1.336 / 1.336 / 1.337 / 1.337
r(N3-C4) / 1.331 / 1.329 / 1.328 / 1.335 / 1.333 / 1.333 / 1.335 / 1.332 / 1.331
r(C4-C5) / 1.403 / 1.409 / 1.411 / 1.399 / 1.402 / 1.404 / 1.398 / 1.406 / 1.409
r(C5-C6) / 1.396 / 1.403 / 1.406 / 1.395 / 1.397 / 1.398 / 1.400 / 1.404 / 1.406
r(C5-C7) / 1.481 / 1.459 / 1.452 / 1.503 / 1.484 / 1.479 / 1.480 / 1.458 / 1.450
r(C6-C1) / 1.390 / 1.388 / 1.388 / 1.391 / 1.391 / 1.390 / 1.386 / 1.384 / 1.384
r(C7-Y8) / 1.210 / 1.634 / 1.780 / 1.205 / 1.623 / 1.766 / 1.211 / 1.635 / 1.781
r(C1-H9) / 1.083 / 1.083 / 1.083 / 1.083 / 1.084 / 1.084 / 1.083 / 1.084 / 1.084
r(C2-H10) / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086
r(C4-H11) / 1.085 / 1.085 / 1.085 / 1.087 / 1.086 / 1.086 / 1.088 / 1.088 / 1.088
r(C6-H12) / 1.086 / 1.085 / 1.085 / 1.085 / 1.084 / 1.084 / 1.084 / 1.084 / 1.084
r(C7-H13) / 1.111 / 1.093 / 1.090 / 1.111 / 1.094 / 1.091 / 1.110 / 1.092 / 1.089
Angle (°)
Ð(C1C2N3) / 123.8 / 123.6 / 123.6 / 123.4 / 123.2 / 123.1 / 123.9 / 123.6 / 123.6
Ð (C2N3C4) / 117.4 / 117.7 / 117.7 / 117.7 / 117.9 / 117.9 / 117.0 / 117.2 / 117.2
Ð (N3C4C5) / 123.4 / 123.8 / 123.9 / 123.5 / 123.7 / 123.7 / 123.8 / 124.3 / 124.4
Ð (C4C5C6) / 118.2 / 117.3 / 117.1 / 118.2 / 117.7 / 117.5 / 118.3 / 117.4 / 117.1
Ð (C5C6C1) / 118.8 / 119.3 / 119.4 / 118.6 / 118.9 / 119.0 / 118.4 / 118.8 / 118.9
Ð (C5C7Y8) / 124.9 / 128.3 / 128.8 / 123.7 / 125.2 / 125.4 / 124.5 / 127.8 / 128.3
Ð (C6C1C2) / 118.2 / 118.3 / 118.3 / 118.6 / 118.7 / 118.8 / 118.6 / 118.8 / 118.8
Ð (C7C5C4) / 121.3 / 123.0 / 123.3 / 120.6 / 120.7 / 120.8 / 120.1 / 118.9 / 118.8
Ð (C7C5C6) / 120.5 / 119.7 / 119.6 / 121.2 / 121.6 / 121.7 / 121.6 / 123.7 / 124.0
Ð(Y8C7H13) / 120.6 / 118.2 / 117.1 / 120.4 / 119.3 / 118.4 / 120.7 / 118.4 / 117.3
Ð (C5C7H13) / 114.5 / 113.5 / 114.1 / 115.9 / 115.5 / 116.2 / 114.8 / 113.8 / 114.4
Ð (C1C2H10) / 120.3 / 120.4 / 120.5 / 120.5 / 120.6 / 120.7 / 120.2 / 120.4 / 120.4
Ð(N3C2H10) / 115.9 / 116.0 / 116.0 / 116.1 / 116.2 / 116.2 / 115.9 / 116.1 / 116.1
Ð(N3C4H11) / 117.2 / 116.9 / 116.9 / 116.1 / 116.3 / 116.4 / 116.2 / 116.2 / 116.2
Ð (C5C4H11) / 119.4 / 119.3 / 119.2 / 120.3 / 120.0 / 119.9 / 120.0 / 119.6 / 119.5
Ð (C5C6H12) / 120.2 / 119.9 / 119.8 / 120.6 / 120.3 / 120.2 / 119.4 / 119.4 / 119.3
Ð (C1C6H12) / 121.0 / 120.8 / 120.8 / 120.7 / 120.8 / 120.8 / 122.2 / 121.8 / 121.8
Ð (C6C1H9) / 121.5 / 121.3 / 121.3 / 121.0 / 120.9 / 120.8 / 121.3 / 121.2 / 121.1
Ð (C2C1H9) / 120.3 / 120.4 / 120.4 / 120.4 / 120.4 / 120.4 / 120.1 / 120.1 / 120.1
Rotational constant (GHz)
A / 5.0769 / 4.8302 / 4.6889 / 5.2396 / 4.5858 / 4.3311 / 5.1107 / 4.8850 / 4.7553
B / 1.5086 / 1.0479 / 0.6666 / 1.5314 / 1.0098 / 0.6448 / 1.4886 / 1.0270 / 0.6506
C / 1.1630 / 0.8611 / 0.5836 / 1.2484 / 0.8839 / 0.5955 / 1.1528 / 0.8486 / 0.5723
Dipole moment (Debye)
4.2002 / 3.8371 / 3.7003 / 3.1406 / 2.6924 / 2.5546 / 1.8240 / 1.8692 / 1.8296

Table S3 Optimized structural parameters of 4-pyridine carboxaldehyde and its sulfur and selenium analogues in the gas phase obtained using the B3LYP/6-311++G(d,p) method

Syn / Transition state / Anti
Bond length (Å)
Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se
r(C1-C2) / 1.390 / 1.389 / 1.388 / 1.394 / 1.393 / 1.393 / 1.390 / 1.389 / 1.388
r(C2-N3) / 1.340 / 1.341 / 1.341 / 1.336 / 1.336 / 1.336 / 1.340 / 1.341 / 1.341
r(N3-C4) / 1.335 / 1.335 / 1.335 / 1.336 / 1.336 / 1.336 / 1.335 / 1.335 / 1.335
r(C4-C5) / 1.394 / 1.393 / 1.392 / 1.394 / 1.393 / 1.393 / 1.394 / 1.393 / 1.392
r(C5-C6) / 1.395 / 1.402 / 1.404 / 1.395 / 1.397 / 1.398 / 1.395 / 1.402 / 1.404
r(C6-C1) / 1.397 / 1.402 / 1.404 / 1.395 / 1.397 / 1.398 / 1.397 / 1.402 / 1.404
r(C6-C7) / 1.488 / 1.466 / 1.458 / 1.504 / 1.486 / 1.480 / 1.488 / 1.466 / 1.458
r(C7-Y8) / 1.208 / 1.631 / 1.777 / 1.205 / 1.622 / 1.764 / 1.208 / 1.631 / 1.777
r(C1-H9) / 1.083 / 1.083 / 1.083 / 1.084 / 1.084 / 1.083 / 1.083 / 1.083 / 1.083
r(C2-H10) / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086
r(C4-H11) / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086 / 1.086
r(C5-H12) / 1.085 / 1.085 / 1.085 / 1.084 / 1.084 / 1.083 / 1.085 / 1.085 / 1.085
r(C7-H13) / 1.110 / 1.092 / 1.089 / 1.111 / 1.094 / 1.091 / 1.110 / 1.092 / 1.089
Angle (°)
Ð(C1C2N3) / 123.6 / 123.8 / 123.9 / 123.7 / 123.9 / 123.9 / 123.6 / 123.8 / 123.9
Ð (C2N3C4) / 117.7 / 117.4 / 117.3 / 117.3 / 117.0 / 117.0 / 117.7 / 117.4 / 117.3
Ð (N3C4C5) / 123.3 / 123.4 / 123.5 / 123.7 / 123.9 / 123.9 / 123.3 / 123.4 / 123.5
Ð (C4C5C6) / 118.6 / 119.1 / 119.3 / 118.4 / 118.7 / 118.8 / 118.6 / 119.1 / 119.3
Ð (C5C6C1) / 118.5 / 117.5 / 117.2 / 118.4 / 117.9 / 117.7 / 118.5 / 117.5 / 117.2
Ð (C6C7Y8) / 124.4 / 127.7 / 128.2 / 123.6 / 125.2 / 125.2 / 124.4 / 127.7 / 128.2
Ð (C6C1C2) / 118.3 / 118.8 / 118.9 / 118.4 / 118.7 / 118.8 / 118.3 / 118.8 / 118.9
Ð (C7C6C1) / 121.3 / 123.3 / 123.7 / 120.8 / 121.0 / 121.1 / 121.3 / 123.3 / 123.7
Ð (C7C6C5) / 120.2 / 119.3 / 119.2 / 120.8 / 121.1 / 121.2 / 120.2 / 119.3 / 119.2
Ð(Y8C7H13) / 120.9 / 118.6 / 117.5 / 120.7 / 119.6 / 118.8 / 120.9 / 118.6 / 117.5
Ð (C6C7H13) / 114.7 / 113.7 / 114.3 / 115.7 / 115.3 / 116.0 / 114.7 / 113.7 / 114.3
Ð (C1C2H10) / 120.4 / 120.2 / 120.2 / 120.1 / 120.0 / 119.9 / 120.4 / 120.2 / 120.2
Ð(N3C2H10) / 116.0 / 115.9 / 115.9 / 116.2 / 116.2 / 116.2 / 116.0 / 115.9 / 115.9
Ð(N3C4H11) / 116.2 / 116.3 / 116.2 / 116.2 / 116.2 / 116.2 / 116.2 / 116.3 / 116.2
Ð (C5C4H11) / 120.5 / 120.4 / 120.3 / 120.1 / 120.0 / 119.9 / 120.5 / 120.4 / 120.3
Ð (C4C5H12) / 120.5 / 120.2 / 120.2 / 120.3 / 120.4 / 120.4 / 120.5 / 120.2 / 120.2
Ð (C6C5H12) / 120.9 / 120.6 / 120.6 / 121.3 / 121.0 / 120.9 / 120.9 / 120.6 / 120.6
Ð (C6C1H9) / 120.1 / 120.1 / 120.1 / 121.3 / 121.0 / 120.9 / 120.1 / 120.1 / 120.1
Ð (C2C1H9) / 121.6 / 121.1 / 121.0 / 120.3 / 120.4 / 120.4 / 121.6 / 121.1 / 121.0
Rotational constant (GHz)
A / 5.0703 / 4.8264 / 4.6865 / 5.3243 / 4.5802 / 4.3267 / 5.0703 / 4.8264 / 4.6865
B / 1.4960 / 1.0379 / 0.6597 / 1.4874 / 1.0032 / 0.6405 / 1.4960 / 1.0379 / 0.6597
C / 1.1552 / 0.8542 / 0.5783 / 1.2166 / 0.8786 / 0.5918 / 1.1552 / 0.8542 / 0.5783
Dipole moment (Debye)
1.8135 / 1.3900 / 1.2694 / 1.9716 / 1.8975 / 1.8850 / 1.8135 / 1.3900 / 1.2694

Table S4 Optimized structural parameters of 2-pyridine carboxaldehyde and its sulfur and selenium analogues in the gas phase obtained using the MP2/cc-pVDZ method

Syn / Transition state / Anti
Bond length (Å)
Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se / Y = O / Y = S / Y = Se
r(C1-C2) / 1.409 / 1.409 / 1.409 / 1.405 / 1.404 / 1.404 / 1.406 / 1.406 / 1.406
r(C2-N3) / 1.345 / 1.343 / 1.343 / 1.349 / 1.350 / 1.350 / 1.348 / 1.347 / 1.347
r(N3-C4) / 1.354 / 1.356 / 1.357 / 1.351 / 1.352 / 1.353 / 1.353 / 1.359 / 1.361
r(C4-C5) / 1.407 / 1.413 / 1.414 / 1.406 / 1.408 / 1.409 / 1.407 / 1.411 / 1.413
r(C4-C7) / 1.501 / 1.481 / 1.475 / 1.513 / 1.497 / 1.494 / 1.497 / 1.479 / 1.474
r(C5-C6) / 1.403 / 1.402 / 1.402 / 1.403 / 1.402 / 1.402 / 1.400 / 1.399 / 1.399
r(C6-C1) / 1.402 / 1.402 / 1.402 / 1.403 / 1.403 / 1.403 / 1.405 / 1.405 / 1.405
r(C7-Y8) / 1.218 / 1.635 / 1.769 / 1.219 / 1.631 / 1.763 / 1.222 / 1.637 / 1.770
r(C1-H9) / 1.095 / 1.095 / 1.095 / 1.094 / 1.094 / 1.094 / 1.095 / 1.095 / 1.095
r(C2-H10) / 1.097 / 1.097 / 1.097 / 1.097 / 1.097 / 1.097 / 1.097 / 1.097 / 1.097
r(C5-H11) / 1.096 / 1.095 / 1.095 / 1.095 / 1.095 / 1.095 / 1.094 / 1.094 / 1.094
r(C6-H12) / 1.095 / 1.095 / 1.095 / 1.095 / 1.095 / 1.095 / 1.095 / 1.095 / 1.095
r(C7-H13) / 1.122 / 1.105 / 1.103 / 1.120 / 1.105 / 1.103 / 1.117 / 1.103 / 1.101
Angle (°)
Ð(C1C2N3) / 124.3 / 124.4 / 124.5 / 124.0 / 124.1 / 124.2 / 123.8 / 124.0 / 124.1
Ð (C2N3C4) / 116.3 / 116.8 / 116.9 / 116.5 / 116.6 / 116.7 / 116.4 / 116.8 / 116.9
Ð (N3C4C5) / 124.0 / 123.1 / 122.9 / 124.1 / 123.8 / 123.6 / 124.4 / 123.5 / 123.2
Ð (C4C5C6) / 118.8 / 119.2 / 119.3 / 118.5 / 118.7 / 118.7 / 118.3 / 118.6 / 118.7
Ð (C4C7Y8) / 124.8 / 126.6 / 126.9 / 122.8 / 123.2 / 123.2 / 123.7 / 126.7 / 127.4
Ð (C5C6C1) / 117.9 / 118.1 / 118.2 / 118.2 / 118.3 / 118.3 / 118.2 / 118.5 / 118.6
Ð (C6C1C2) / 118.7 / 118.4 / 118.3 / 118.7 / 118.5 / 118.5 / 118.9 / 118.5 / 118.4
Ð (C7C4N3) / 117.2 / 118.4 / 118.6 / 115.1 / 115.9 / 116.0 / 115.3 / 114.0 / 113.8
Ð (C7C4C5) / 118.8 / 118.5 / 118.5 / 120.8 / 120.4 / 120.4 / 120.3 / 122.6 / 123.0
Ð(Y8C7H13) / 121.6 / 119.9 / 119.0 / 121.5 / 120.6 / 120.0 / 122.9 / 121.2 / 120.2
Ð (C4C7H13) / 113.5 / 113.6 / 114.2 / 115.7 / 116.2 / 116.8 / 113.4 / 112.1 / 112.4
Ð (C1C2H10) / 120.0 / 119.9 / 119.9 / 120.3 / 120.3 / 120.3 / 120.2 / 120.2 / 120.2
Ð(N3C2H10) / 115.8 / 115.7 / 115.6 / 115.7 / 115.6 / 115.5 / 116.0 / 115.8 / 115.7
Ð (C4C5H11) / 120.0 / 119.9 / 119.8 / 120.4 / 120.2 / 120.1 / 119.0 / 119.3 / 119.4
Ð(C6C5H11) / 121.1 / 120.9 / 120.9 / 121.1 / 121.2 / 121.1 / 122.7 / 122.1 / 121.9
Ð (C5C6H12) / 121.0 / 120.9 / 120.8 / 120.8 / 120.7 / 120.6 / 121.0 / 120.7 / 120.6
Ð (C1C6H12) / 121.0 / 121.1 / 121.0 / 121.0 / 121.0 / 120.0 / 120.8 / 120.8 / 120.8
Ð (C6C1H9) / 121.2 / 121.3 / 121.4 / 121.2 / 121.3 / 121.3 / 121.1 / 121.3 / 121.3
Ð (C2C1H9) / 120.1 / 120.2 / 120.2 / 120.1 / 120.2 / 120.2 / 120.0 / 120.2 / 120.3
Rotational constant (GHz)
A / 5.3753 / 5.0887 / 4.8496 / 5.2826 / 4.7767 / 4.3648 / 5.3749 / 5.0879 / 4.8484
B / 1.5686 / 1.0646 / 0.6322 / 1.5819 / 1.0349 / 0.6180 / 1.5690 / 1.0651 / 0.6326
C / 1.2143 / 0.8804 / 0.5593 / 1.2759 / 0.9127 / 0.5788 / 1.2145 / 0.8807 / 0.5596
Dipole moment (Debye)
4.6068 / 4.1239 / 3.8680 / 3.8241 / 3.1866 / 2.8837 / 3.2892 / 3.1559 / 3.0089

Table S5 Optimized structural parameters of 3-pyridine carboxaldehyde and its sulfur and selenium analogues in the gas phase obtained using the MP2/cc-pVDZ method