Dissociative recombination of CH 2 OH + and CD 2 OD + Mathias Hamberg Wolf Geppert, Richard Thomas Fabian Österdahl, Vitaly Zhaunerchyk, Jacek Semaniak, Magdalena Kaminska Magnus af Ugglas, Anders Källberg Mats Larsson

Ion-electron processes AB + (v=n) + e - AB + h Radiative recombination (slow) AB + (v≠n) + e - Elastic and superelastic scattering A + + B - Resonant ion pair formation A + B Dissociative Recombination (DR)

DR example + e-e- e-e-

Direct process AB**AB + Internuclear separation Potential energy A+B + A+B

Indirect process AB**AB + Internuclear separation Potential energy AB* A+B + A+B

Where can we find Dissociative recombination process ? Comas of comets The northern lights Dark clouds Tukamak plasma’s Lightning

Why CH 2 OH + and CD 2 OD + ? Alcohols are fun So are their products Previous investigations about methanol Significant pathways for production and destruction of: NH 4 +, NH 3, H 2 O, H 3 O + Pathways competes with DR-reaction

How and what JIMIS hollow cathode ion source Isomerization? Symmetries, energy barrier? Hydroxymethylion CH 2 OH + CH 2 OH + Methoxy ion CH 2 OH + CH 2 OH +

CRYRING Formation of the ions with JIMIS Mass selection with bending magnet RFQ Injection Acceleration via RF e - -cooler Cooling and interaction region Detection of neutrals with SBD

e - -cooler

Detection

Branching Ratios Spectrum for CH 2 OH + Spectrum for CD 2 OD + Difficult to resolve

Branching Ratios Reaction channels: CH 2 OH + CD 2 OD + CH x O CD x O α H 2 O + CH D 2 O + CD β H 2 O + CH D 2 O + CD β CH 2 + OH CD 2 + OD γ CH 2 + OH CD 2 + OD γ α: non C-O bondbreaking β, γ:C-O bondbreaking

TransmissionprobabilityT=0.297 Branching Ratios Probability matrix: P = [TT^2 T^2 0T(1-T) 0 0T(1-T) 0 00 (1-T) 00 (1-T) 0T(1-T) 0 ] 0T(1-T) 0 ] Ch.αβ γ (CH x O) (H 2 O + CH) (CH 2 + OH) (CH x O) (H 2 O + CH) (CH 2 + OH) Measured counts for CH 2 OH + α β γ α β γ

Branching Ratios CH 3 O + :CD 3 O + : CH x O + (98%)CD x O + ( 92%) α H 2 O + CH (0.7%)D 2 O + CD (2%) β CH 2 + OH (1.6%) CD 2 + OD (6%) γ Contrary to the CH 3 OH 2 + ion, the pathways preserving the bond between the heavy atoms dominate.

Reaction cross section Ramping the cathode voltage linearly according to the figure  The following spectrum was achieved  Cooling 1 eV

Reaction cross section Preliminary evaluation of the data yielded a reaction rate coeffecient of CH 2 OH + 6.8*10 -7 (T/300) cm 3 mol -1 s -1 CD 2 OD + 8.4*10 -7 (T/300) cm 3 mol -1 s -1 Error bars < 15%, biggest factor is the ion current measurement Results ?

Discussion Contrary to the CH 3 OH 2 + ion, the pathways preserving the bond between the heavy atoms dominate Contrary to the CH 3 OH 2 + ion, the pathways preserving the bond between the heavy atoms dominate Why? C-O bond has double bond character, although DR is known to often break strong bonds Why? C-O bond has double bond character, although DR is known to often break strong bonds Further investigations will take place in order to increase the resolution and resolve the different CD x O + channels Further investigations will take place in order to increase the resolution and resolve the different CD x O + channels Isomerization: Hydroxymethyl ion CH 2 OH + likely to be dominating during the measurements Isomerization: Hydroxymethyl ion CH 2 OH + likely to be dominating during the measurements Overall impact: Results might be used within astrochemical models Overall impact: Results might be used within astrochemical models

Credits Wolf Geppert Mats Larsson Fabian Österdahl Vitali Zhaunerchyk Richard Thomas, Magnus af Ugglas Anders Källberg Ansgar Simonsson,and the rest of the CRYRING-crew