INFRARED SPECTRA OF g BUTYROLACTONE DIMERS AND TRIMERS

INFRARED SPECTRA OF g. BUTYROLACTONE DIMERS AND TRIMERS ISOLATED IN INERT GAS MATRICES. JONATHAN ROSLUND, C. A. BAUMANN Department of Chemistry University of Scranton

g-Butyrolactone

Carbonyl Region

Methodology n n n Matrix: N 2 , Ar Dilution: 1: 340 or 1: 1040 Deposition temperature: 20 K 32 scans at 1 cm-1 resolution DFT: b 3 lyp/6 -31++G(d, p)

ab ag Dimers bg gg

Stacked Trimers a, b/g, a b, b/g, g

agg bgg Ring Trimers aag

Covalent Trimer (1, 3, 5 trioxane 2, 4, 6 trispiro 2 oxolane) Bodor, N. ; Huang, M. J. Int. J. of Quantum Chem. 1992, 44, 81.

D(E+ZPE) (k. J/mol-1) Monomer (a, b) Dimer (a, g) Dimer (b, g) Dimer (g, g) Dimer m (D) Separation (pm) 4. 98 -19. 5 -21. 1 -22. 3 1. 94 1. 46 0. 79 0. 004 R(O-H’b) 263 R(Oring-H’g) 309 R(O’-Ha) 268 R(O’ring-Hb) 312 R(O-H’a) 249 R(O’ring-Hg) 326 R(O’-Hg) 268 R(Oring-H’b) 335 R(O’-Hb) 276 R(O-H’g) 271 R(Oring-H’a) 283 R(O-H’b) 272 R(O’-Ha) 274 R(O-H’g) 259 R(Oring-H’a) 302 R(O’-Hg) 259 R(O’ring-Ha) 302 R(O’-Ha) 303 R(O-H’a) 303

D(E+ZPE) (k. J/mol-1) Monomer (a, b/g, a) Trimer (b, b/g, g) Trimer m (D) Separation (pm) 4. 98 -36. 4 -37. 2 5. 36 4. 72 R(O-H’a) 253 R(Oring-H’a) 334 R(O’-H’’b) 265 R(O’ring-H’’g) 306 R(O’-Hg) 270 R(O’ring-Hg) 312 R(O’-Ha) 284 R(O’’ring-H’a) 309 R(O’’-H’a) 275 R(O’’ring-H’a) 338 R(O-H’b) 275 R(Oring-H’a) 346 R(O-H’a) 297 R(O’ring-Hg) 338 R(O’-H’’g) 253 R(O’ring-H’’a) 298 R(O’-Hb) 272 R(O’’ring-H’a) 305 R(O’-Ha) 298 R(O’’-H’g) 255

D(E+ZPE) (k. J/mol-1) Monomer (a, g, g) Ring Trimer (b, g, g) Ring Trimer (a, a, g) Ring Trimer m (D) Separation (pm) 4. 98 -50. 2 -47. 2 -48. 9 0. 76 1. 32 1. 94 R(O-H’g) 246 R(Oring-H’a) 281 R(O’-H’’g) 249 R(O’ring-H’’a) 302 R(O’’-Ha) 248 R(O’’ring-Ha) 283 R(O-H’a) 276 R(O’-H’’b) 260 R(O’’-Hg) 270 R(O’-H’’b) 246 R(Oring-H’a) 287 R(O-H’g) 249 R(O’ring-H’’g) 265 R(O’’-Hg) 252 R(O’’ring-Ha) 278 R(O-H’a) 267 R(O’’-Ha) 279 R(O-H’g) 251 R(Oring-H’a) 282 R(O’-H’’a) 244 R(O’’ring-Hg) 277 R(O’’-Ha) 250 R(O-H’a) 266 R(O’-H’’g) 259 R(O’’-Hg) 273

Carbonyl Region

Carbonyl Region-d 6

C-H Stretches

C-D Stretches

Conclusions n n Evidence for dimers and trimers Ring trimers Most of the C-H stretches are blue-shifted Solid and liquid: dimers, trimers, larger aggregates

Acknowledgements n Faculty Research Committee