INFARED SPECTROSCOPY OF Mn(CO 2 ) n − CLUSTER ANIONS Michael C Thompson, Jacob Ramsay and J. Mathias Weber June 24, th International Symposium on Molecular Spectroscopy

Transition Metal Complexes with CO 2 Previous work on Au(CO 2 ) n - and Ag(CO 2 ) n - Formate binding motif Knurr, B. J.; Weber, J. M.; J. Am. Chem. Soc. 2012, 134, Knurr, B. J.; Weber, J. M.; J. Phys. Chem. A 2013, 117, Previous work on Ni(CO 2 ) n - and Co(CO 2 ) n - Butterfly binding motif Knurr, B. J.; Weber, J. M.; J. Phys. Chem. A 2014, 118, Knurr, B. J.; Weber, J. M.; J. Phys. Chem. A 2014, 118, What will be the binding motifs of CO 2 with Mn??

cluster + h hot cluster fragments Experimental Method: IR Photodissociation Condition: BE ≤ E + hν

Vibrational Spectroscopy of Mass Selected Anions Detection by evaporation of CO 2 ligands: [Mn(CO 2 ) n ] – + h  [Mn(CO 2 ) n–1 ] – + CO 2 Power meter power meter IR-OPO/OPA 600 – 4500 cm mJ / 5 ns Mn

Expectations Co and Ni Studies on Co(CO 2 ) n - and Ni(CO 2 ) n - have shown a butterfly binding motif Charge distribution: Metal ≈+1; ligand CO 2 ≈-1 Mn Mn may have similar binding characteristics (1 st row transition metal) It is possible that Mn may show completely different binding (d 5 metal)

Mn + : [Ar] 4s 2 3d 4 Different spin state may affect bond angles and lengths Quintet structures are typically 1 eV lower than triplet structures Singlet structures are normally 1-3 eV higher in energy than the higher spin states Triplet Singlet Quintet Multiple Spin States! E

Data unpublished at time of archiving. They may be restored to this file after publication.

Future Work calculations beyond n=4 to confirm the solvent induced shifts (in progress) Mn(CO 2 ) n (H 2 O) m - (completed) Other 1 st row metals: Fe, Zn Bi(CO 2 ) n - (in progress) Other p-block metals: Sn, Pb

Dramatis Personae NSF AMO PFC

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