1 -RJ16- NON COVALENT INTERACTIONS AND INTERNAL DYNAMICS IN ADDUCTS OF FREONS 69 th Symposium, Urbana-Champaign, June 16-20, 2012 Dipartimento di Chimica ”G.Ciamician” - Universita’di Bologna Dep. Química Física y Química Inorganica - Universidad de Valladolid Departamento de Quimica Fisica, Universidad del Pais Vasco, Bilbao. Q. Gou, L. Evangelisti, G. Feng, L. Spada, M. Vallejo, A. Lesarri, E. Cocinero, W. Caminati.

2 1)Oligomers of freons containing hydrogen. Weak hydrogen bonds. After investigating the rotational spectra of several complexes of freons, we can classify them in some categories, and relate the nature of the non bonding interactions to the chemical composition of the involved freons: 2) Adducts of freons containing hydrogen with other small molecules. Weak hydrogen bonds. 3) Adducts of perhalogenated freons with other small molecules. Halogen bonds. 4) Adducts of unsaturated perhalogenated freons with other small molecules n →  * interactions.

(CH 2 F 2 ) n First pure rot. Spectrum of a tetramer of an asymmetric top

Adducts of Freons containing hydrogen with small molecules: Weak hydrogen bonding and dynamics W.Caminati, J.-U.Grabow J.C.López, J.L.Alonso, Angew.Chem.Int.Ed (2005). J. Am. Chem. Soc. 1999, 121, Angew. Chem. Int. Ed., 2006, 45, 2438.

V 2 lower then in CH 2 F 2 -H 2 O The 0 + and 0 ­ component lines of the 4 04 ­3 03 μ a transition of normal CH 2 F 2 – H 2 CO Relative intensity 1:3 5 Q.Gou, G.Feng, L.Evangelisti, M.Vallejo, A.Lesarri, E.J.Cocinero, W.Caminati, Phys. Chem. Chem. Phys., 15, 6714 (2013) Adducts of Freons containing hydrogen with small molecules: Weak hydrogen bonding and dynamics

6 C-H  Cl preferred to C- H  F Adducts of Freons containing hydrogen with small molecules: Weak hydrogen bonding and dynamics G.Feng, Q.Gou, L.Evangelisti, M.Vallejo, A.Lesarri, E.J.Cocinero, W.Caminati, Phys. Chem. Chem. Phys., (2014), just out

Perhalogenated freons: Halogen bond, much dynamics L.Evangelisti, G.Feng, P.Écija, E.J.Cocinero, F.Castaño, W.Caminati, Angew.Chem.Int.Ed., –7810 (2011) Free rotation of Water → Symmetric top Cl  O halogen bond “Real” Symmetric top Cl  N halogen bond G.Feng, L.Evangelisti, N.Gasparini, W.Caminati, Chem.Eur.J., (2012)

8 Perhalogenated freons: Halogen bond, much dynamics

9 Calculated and experimental rotational constants of CF 3 Cl-CH 3 F calcl.exptl. A/MHz (28) B/MHz (3) C/MHz (3) χ aa /MHz (1) (χ bb -χ cc )/MHz (3) Four isotopologues: CF 3 35 Cl-CH 3 F CF 3 37 Cl-CH 3 F CF 3 35 Cl-CD 3 F CF 3 37 Cl-CD 3 F Perhalogenated freons: Halogen bond, much dynamics

10 A 00 = A r + [W 00 (2) F  a 2 ] CF3 + [W 00 (2) F  a 2 ] CH3 B 00 = B r + [W 00 (2) F  b 2 ] CF3 + [W 00 (2) F  b 2 ] CH3 C 00 = C r + [W 00 (2) F  c 2 ] CF3 + [W 00 (2) F  c 2 ] CH3 V 3 ≈ 7 cal mol -1 Values of F  g 2 of the two internal rotation tops in the four isotopologues of the complex CF 3 35 Cl-CH 3 FCF 3 37 Cl-CH 3 FCF 3 35 Cl-CD 3 FCF 3 37 Cl-CD 3 F CF 3 F  a 2 /MHz F  b 2 /MHz CH 3 F  a 2 /MHz F  b 2 /MHz Assuming there’s no coupling between the two free internal motions: Perhalogenated freons: Halogen bond, much dynamics Q.Gou, L. Spada, E.J. Cocinero, W. Caminati, J. Phys. Chem. Lett., (2014)

Recorded 3 1,2  2 1,1 transition of the observed conformer showing the 35 Cl hyperfine structure. Each line exhibits the doppler doubling. EXP Unsaturated perhalogenated freons with other small molecules n→  * interactions. Q.Gou, G.Feng, L.Evangelisti, W.Caminati, Angew. Chem. Int. Ed., (2013).

ΔE/cm A/MHz B/MHz C/MHz χ aa (Cl)/MHz χ bb -χ cc (Cl)/MHz χ aa (N)/MHz χ bb -χ cc (N)/MHz Unsaturated perhalogenated freons with other small molecules n →  * interactions. This part concerns the investigation during the last few months of C 2 ClF 3 -Ammonia, and involves Q.Gou, L.Spada, Y.Gebose (Antwerpen), S. Melandri & myself.

3 1,3 ←2 1,2 F 1 ′+1/2, F′ ← F 1 ″ +1/2, F″ Unsaturated perhalogenated freons with other small molecules n →  * interactions.

35 Cl- 14 NH 3 37 Cl- 14 NH 3 35 Cl- 15 NH 3 35 Cl- 14 ND 3 A/MHz (2) (2) (6) (4) B/MHz (1) (1) (1) (7 ） C/MHz (1) (2) (7) (5) χ aa (Cl)/MHz (4)-18.71(1)-19.85(4)-14.33(2) χ bb -χ cc (Cl)/MHz (7)-38.63(1)-51.78(3)-51.82(2) χ ab (Cl)/MHz55.91(7)46(1)[55.91]57(1) χ bc (Cl)/MHz12(4)-[12] χ ac (Cl)/MHz10.3(5)6.8(7)[10.3]17.8(6) χ aa (N)/MHz-0.404(4)[-0.404]--0.94(1) χ bb -χ cc (N)/MHz-0.435(7)[-0.435]--1.09(2) χ ab (N)/MHz0.7(1)[0.7]-3.2(8) χ ac (N)/MHz1.8(6)[1.8]- D J /kHz2.518(1)2.416(2)2.547(8)2.654(6) D JK /kHz-6.71(2)-6.27(9)-7.4(2)-9.2(2) D K /kHz16.93(2)[16.93] d 1 /kHz-0.370(1)[-0.370]-0.414(9)-0.589(7) d 2 /kHz-0.115(2)[-0.115] σ/kHz N Unsaturated perhalogenated freons with other small molecules n →  * interactions.

CF 3 Cl C2H4C2H4 C2F4C2F4 CF 2 CFCl Sites of interaction