TWO-DIMENSIONAL (2+n) REMPI SPECTROSCOPY: STATE INTERACTIONS, PHOTOFRAGMENTATIONS AND ENERGETICS OF THE HYDROGEN HALIDES JINGMING LONG, HUASHENG WANG, KRISTJÁN MATTHÍASSON, HELGI RAFN HRÓÐMARSSON, ÁGÚST KVARAN Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavík, Iceland. Oral presentation at “international Symposium on Molecular Spectroscopy; 66th Meeting” June 20-24, 2011, Ohio State University

Voltage devider HV - 2Kv HX nozzle Turbo Pump TOF lense MCP detector oscilloscope computer Excimer Laser In out Dye- Laser SHG Time delay  S laser control Pellin Broca prism SHG control In out

REMPI = Resonance Enhanced MultiPhoton Ionization Resonance Excitation to high energy states of neutral species, followed by photon ionization; For example: 1xh 2xh 2 E AB AB + + e AB**

Intensity Mw H+H+ 35 Cl + H 35 Cl + H 37 Cl + 12 C + Two photon resonance excitation= cm -1 Mass spectrum RCl = HCl

Mw / rel. 35 Cl + H 35 Cl + H 37 Cl + 2xhv Mw 35 Cl + 37 Cl + H 37 Cl + H 35 Cl + /cm -1

r(H-X) Energy HX H X ** H + --X - HX + H + X + e-e- e-e- + HX REMPI: IE limit v´ J´ v´ J´

270 cm -1

V 1  + (v´=m+10)

H 35 Cl + 35 Cl + Q J´=J´´ = HCl, F 1  2 2h  / cm -1 Intensity

r(H-X) Energy HX H X ** H + --X - HX + / HX + H + X + e-e- e-e- + HX REMPI: IE limit v´ J´ v´ J´

State Interactions ? (1) /  0 (2) /  0 12  c 1  0 1  a  c 2  0 2 = +  b =  c 1 ´  0  c 2 ´   c 1  c = 1 E

W 12 : Interaction strength (1) /  0 (2) /  0 12  c 1  0 1  a  c 2  0 2 = +  b =  c 1 ´  0  c 2 ´   c 1  c = 1 E

(1) /  0 (2) /  0 12  c 1  0 1  a  c 2  0 2 = +  b =  c 1 ´  0  c 2 ´   c 1  c = 1 E( ) E( J´ ) EE E

H 35 Cl + 35 Cl + Q J´=J´´ = HCl, F 1  2 2h  / cm -1 Intensity

x  E J´=8 = 11.3 cm -1 HCl: F 1  2 V 1   c 1 2  c 2 2 X ?

H 35 Cl + 35 Cl + Q J´=J´´ = HCl, F 1  2 2h  / cm -1 Com- press- ion E x p a n s i o n Intensity



x  E J´=8 = 11.3 cm -1 HCl: F 1  2 V 1   c 1 2  c 2 = X? 6 cm -1 from line shifts

r(H-X) Energy HX H X ** H + --X - HX + / HX + H + X + e-e- e-e- + HX REMPI: IE limit v´ J´ v´ J´ c1c1 2 c2c2 2 ? X +

r(H-X) Energy HX H X ** H + --X - HX + / HX + H + X + e-e- e-e- + HX REMPI: v´ J´ v´ J´ H + X X+X+

r(H-X) Energy HX H X ** H + --X - HX + / HX + H + X + e-e- e-e- + HX REMPI: v´ J´ v´ J´ HX*** H + X* X+X+

r(H-X) E HX H + --X - HX + / HX + H + X + e-e- HX REMPI: v´ J´ v´ J´ c1c1 2 c2c2 2 X+X+ X X* c1c1 c2c I (HX + ) = c1c1 c2c I (X + ) = Ry:I.P./V: c2c2 2 c2c2 2 == X+)/X+)X+)/X+)  =    X + ) /    X + )  = X+)/X+)X+)/X+)

r(H-X) E HX H + --X - HX + / HX + H + X + e-e- HX REMPI: v´ J´ v´ J´ c1c1 2 c2c2 2 X+X+ X X* c2c2 2 c2c2 2   = X+)/X+)X+)/X+)   = X+)/X+)X+)/X+)

Exp.Q i=35i=37 I( i Cl + )/I(H i Cl + ) Exp.Q Calc. V,v´ = 20 Calc. V,v´=20 j 3  - 1 ; ´=0 isotopomersH 35 ClH 37 Cl J´ closest resonances(J´ res )22 |  E(J´ res ) | / cm W 12 (J´ res ) / cm c 1 2 (c 2 2 ) (J´ res )0.89(0.11)0.81(0.19)   14 x x H i Cl j 3  - 1 > > <   K. Matthíasson et al. J. Chem. Physics, 134, , (2011)

r(H-X) Energy HX HX** H + --X - HX + / HX + H + X + e-e- HX REMPI: v´ J´ v´ J´ H + X X+X+ j 3  - 1 t 3  + 1 S/O

H 35 Cl f 3  2 f 3  1 I( 35 Cl + )/I(H 35 Cl + ) States f32f32 f31f31 J´ closest resonances(J´ res )56 |  E(J´ res ) | / cm W 12 max (J´ res )/ cm c 1 2 (J´ res )  00 1.0 x < > Exp.Q Calc. V,v´=9 Exp.S Calc. V,v´=8 <

H 35 Cl f 3  2 f 3  1 I( 35 Cl + )/I(H 35 Cl + ) Exp.Q Calc. V,v´=9 Exp.S Calc. V,v´=8  No dissociation No predissociation pathway Dissociation: Predissociation by S/O couplings via “Gateway Rydberg states ( 1 , 3  )” :

H 37 Cl j 3  - (0 + ) Exp. Q

J´=0 J´=6 J´=6 v´=21 J´=6 v´=20 J´=0 : : j 3  - (0 + ), v´=0 V 1  (0 + ) H 37 Cl Near resonance  S  ´=0 E/cm -1

Calc. V,v´=20 V,v´=21 H 37 Cl j 3  - (0 + ) Exp. Q V´ statesv´=20v´=21 J´ closest resonances(J´ res )6 |  E(J´ res ) | / cm W 12 (J´ res ) / cm c 1 2 (J´ res )0.82  4.0(52 x )

H 79 Br

J´=0 J´=6 J´=9 J´=6 v´=m+5 H 79 Br E 1  (0 + ), v´=0 J´=9 v´=m+4 J´=0 V 1  (0 + ) Off resonance S S  ´=0 J´=6 J´=0 E/cm -1

H 79 Br, E(v´=0) I( 79 Br + )/I(H 79 Br + ) Linewidth/ cm -1

: Victor Huasheng Wang Kristján Matthíasson Jingming Long Helgi Rafn Hróðmarsson Coworkers: *