HCl, negative ion detections 1hv ion-pair spectra (slides 3-4) Loock´s prediction about H+ + Cl- formation channels(slides 5-6) Energetics vs Dye for V(v´= ) (slides 8-10) Cl- via E(v´=0) excitation(?) (slides 11-12) First neg. Ion detections (slides 13-21) V(v´=12), Q(1), Mass spectra (slides 14-17) V(v´=12), Q(0-3), i=35,37; Mass spectra (slides 20-24) i=37 vs 35 time delay(?) (slides 25-28)

Loock´s papers: (HBr) (HCl) (HCl & HBr) Is dealing with E and V(v´=9,10,11) HCl: dealing with E(0) and V(9,11-13,15) & g(0) HBr: dealing with E(0) and V(m+3,m+5 to m+8) & H(0) “For selected intermediate states HCl was found to dissociate into the H++Cl− ion pair with over 20% relative yield.”

Our paper (´93): : nm

See: cm-1 H+ + Cl- threshold cm-1: thr. For (2+1)REMPI for V(v´=12) nm

NB!: Max contribution to H+ + Cl- formation For v´=12, but significant contribution Also from v´=11 and 13 H+ + Cl- #

NB!: If Loocks interpretation in # (see above slide 5) is correct, i.e. that Cl - formation occurs via bound to bound transition,V(v´=12 ) -> (A)nl  (Rydberg state), the Cl - formation should be greatly J´ dependent! NB!: they used Q(J´=0) and Q(J´=1) lines only. Idea: Could it be that the H + + Cl - formation is mainy J´ dependent (and less v´ dependent)?

Dye curve C480 (x4) V(v´=12) cm-1 EF

Dye curve C480 (X4) V(v´=12); cm-1 V(v´=11) cm-1 V(v´=13); cm-1 E F V v´=0

We should be able to scan V(v´=11,12 13) by use of Dye: 480

E(v´=0) mixes strongly with V(v´=11) Therefore, one might expect to see Cl - formation via excitation to E(v´=0) as well!

(Q(J´=J´´=1)) e-e- H-H- (2+n)REMPI, HiCl; i = 35,37 V(v´=12,J´) <-<- X(v´=0,J´´) Q lines ; Layout:2, Graph:7 2hv/cm -1 i=35 i=37

35 Cl + H 35 Cl + H-H+H-H+ 35 Cl - 37 Cl - C n H m +... e-e- (slide 15)(slide 16) Mw (slide 17) H i Cl; i = 35, cm -1 (Q(1)) ; Lay:1, Gr:6

C-C- CH - CH 2 - C2-C2- C2H-C2H- O - /CH 4 - (?) OH - (?) H i Cl; i = 35, cm -1 (Q(1)) ; Lay:1, Gr:6 (?) Mw

35 Cl + H 35 Cl + 35 Cl - 37 Cl - Mw H i Cl; i = 35, cm -1 (Q(1)) ; Lay:1, Gr:6

; Lay:1, Gr:6 H-H+H-H+ e-e- Mw H i Cl; i = 35, cm -1 (Q(1))

1D-REMPI spectra: ; Lay:3, Gr:8 e-e- 35 Cl - 35 Cl - smoothed Q(2) i = 35 Q(1) i = 35

Main 35 Cl - signals seem to appear for Q(1) and Q(2)

H i Cl; i = cm -1 (Q(0)) ; Lay:6, Gr:16 35 Cl - Mw

35 Cl + H 35 Cl + 35 Cl - 37 Cl - Mw H i Cl; i = cm -1 (Q(1)) ; Lay:1, Gr:6 35 Cl - 37 Cl -

35 Cl - (slide 21) H i Cl; i = cm -1 (Q(2)) ; Lay:4, Gr:10 Mw 35 Cl -

H i Cl; i = cm -1 (Q(3)) ; Lay:5, Gr:13 35 Cl - Mw

H i Cl; i = cm -1 (Q(1)) ; Lay:7, Gr:15 No 35 Cl - signal Possibly some 37 Cl - (?) 37 Cl - (?) Mw

H-H- e-e- i=35 i=37; Q(1) Mw ; Lay:8, Gr:17 Small but significant time delay for i= 37 relative to that for i = 35 (?) Q(0) Q(4) Q(1) Q(3) Q(2)

Small but significant time delay for i= 37 relative to that for i = 35 ; Lay:8, Gr:17 Mw i=35, Q(0-4) i=37; Q(1)

Small but significant time delay for i= 37 relative to that for i = 35 ; Lay:8, Gr:17 Mw i=35, Q(0-4) i=37; Q(1)

NO delay(??) for i= 37 relative to that for i = 35 Mw 35 Cl - 37 Cl - 37 Cl - (?) ; Lay:8, Gr:17 i=35, Q(0-4) i=37; Q(1)

Comments/suggestions: Although not quite clear it looks as if the Cl- signals are formed in a different way to that of other negative ions (CnHm+,...), most likely as 2hv + HCl -> [H + Cl - ]*(V(12,J´)) [H + Cl - ]*(V(12,J´))+hv ->..-> H+ + Cl- Let´s improve signals. Check HCl*(V(v´=11)), which ought to show H+ + Cl- ion formations also (see slide 5) Since E(v´=0) mixes strongly with V(v´=11), excitation via E(0) might also show Cl - ions (NB!: E(0) is reachable by C480; see slide no. 9) Since F(v´=0) is “pure” Rydberg state and does not mix with the V state it should show NO H+ + Cl - (NB!: F(0) is reachable by C480; see slide no. 9)