1. © HCCCCCNHCCCCCN A rotating dipolar molecule generates radio waves that can be detected by microwave spectroscopy

2. H−C≡C−C≡C−C≡N - the original chart recording hp 8340

4. 38.0 37.537.036.5GHz H−C ≡ C−C ≡ C−C ≡ N a b c d e f 13 C and 15 N isotopic satellites f aeb cd J = 14←13 2 1 3 4 5 678 ν 11 0 H−C ≡ C−C ≡ C−C ≡ N

5. H − C ≡ C − C ≡ N 1.058 1.378 Å 1.0568 1.3621 1.3636 Å Literature HC 3 N HC 5 N (r s ) Å H-C 1.09 >1.058 >1.0568 C-C 1.54 >1.378 >1.3621 1.3636 C≡C 1.20 <1.205 <1.2087 1.2225 C≡N 1.16 <1.159 <1.1606 1.2087 1.2225 1.1606 Å 1.205 1.159 Å Delocalisation effects on bond lengths?

7. 40383634323028 46 50 54 J 44 42 48 525658 SiMe 3 C≡C−C≡C−C≡N GHz 60

8. F(J) = BJ(J+1) 5 J 4 3 2 1 0 30B 20B 12B 6B 2B 0

12. 38.0 37.537.036.5GHz H−C ≡ C−C ≡ C−C ≡ N a b c d e f 13 C and 15 N isotopic satellites f aeb cd J = 14←13 2 1 3 4 5 678 ν 11 0 H−C ≡ C−C ≡ C−C ≡ N

14. 40383634323028 46 50 54 J 44 42 48 525658 SiMe 3 C≡C−C≡C−C≡N GHz 60

15. H-C 1.09 H-N 1.00 H-O 0.96 C-C 1.54 C-N 1.47 C-O 1.43 C-Cl 1.76 C-Br 1.94 C-I 2.14 C=C 1.35 C=N 1.30 C=O 1.22 C≡C 1.20 C≡N 1.16

16. 9 11 J 101213 H−C≡C−C≡C−C≡N 14 40383634323028GHz

21. 2B ca 2.7 GHz

22. 2B ca 2.7 GHz so B is about 1.35 GHz