Electronic Spectroscopy of the 6p ← 6s Transition in Au–Ne Adrian M. Gardner, Richard J. Plowright, Carolyn D. Withers, Timothy G. Wright, Michael D. Morse and W.H. Breckenridge

Coinage Metal-Rare Gas Complexes Cu–Kr 1 Ag–Ar, 2,3 Ag–Kr, 2 Ag–Xe 2 Au–Ne, 4 Au–Ar, 5,6,7 Au–Kr, 5,8 Au–Xe 5,9 1.Brock and Duncan, Chem. Phys. Lett., 247, 18 (1995) a 2. Brock and Duncan, J. Chem. Phys., 103, 9200 (1995) 3.Jouvet et al., J. Chem. Phys., 94, 1759 (1991) a 4. Plowright et al., J. Phys. Chem. A., 114, 3103 (2010) 5.Hopkins et al., J. Chem. Phys., 132, (2010) a 6. Plowright et al., J. Chem Phys., 127, (2007) 7.Knight et al., Chem. Phys. Lett., 273, 265 (1997) aa 8. Plowright et al., J. Chem Phys., 129, (2008) 9. Plowright et al., Phys. Chem. Chem. Phys., 11, 1539 (2009)

Experimental The Au–Ne D 2  3/2,1/2  X 2  1/2 + complex transitions were investigated using (1+1) Resonance Enhanced Multiphoton Ionization, REMPI, Spectroscopy. The D 2  Ω states have electron density which is off the internuclear axis. This results in the dissociation energy of the D 2  Ω states being considerably greater than the X state. The E 2  1/2 +  X 2  1/2 + transition has not be observed for any CM–RG complex.

Experimental Apparatus

Results: Au–Ne D 2  3/2  X 2  1/2 + Transition A (1+1) REMPI spectrum of D 2  3/2  X 2  1/2 + transition was obtained. 4 The vibrational numbering was assigned based on isotopic shifts between Au– 20 Ne and Au– 22 Ne. 4. Plowright et al., J. Phys. Chem. A., 114, 3103 (2010)

Results: Au–Ne D 2  3/2  X 2  1/2 + Transition MorseLeRoy-Bernstein ee exeexe DeDe D0D D0D0 (a) Morse and (b) LeRoy-Beinstein plots to the observed transitions for Au– 20 Ne. Spectroscopic parameters determined for the D 2  3/2 state of Au–Ne Plowright et al., J. Phys. Chem. A., 114, 3103 (2010)

Results: Au–Ne D 2  1/2  X 2  1/2 + Transition The Au–Ne spectrum expected in the vicinity of the Au 2 P 1/2  2 S 1/2 transition was not observed. No Au–Ne D 2  1/2  X 2  1/2 + transition observed Au–Ar D 2  1/2  X 2  1/2 + transition observed Carrier gas changed to Ar Au–Ar D 2  3/2  X 2  1/2 + transition observed Laser dye changed Au–Ne D 2  3/2  X 2  1/2 + transition observed Carrier gas changed to Ne Laser dye changed

Results: Au–Ne D 2  1/2  X 2  1/2 + Transition CASSCF+MRCI+Q/aVQZ potential energy curves were calculated for the D 2  1/2, D 2  3/2 and E 2  1/2 + states. The D 2  1/2 and E 2  1/2 states interact resulting in the D 2  1/2 state having only a shallow minimum at ≈5 Å. The R e of the X 2  1/2 + state has been calculated at the RCCSD(T)/daCV  Z level as ≈3.8 Å.

Results: Au–RG X 2  1/2 + State Potential energy surfaces have been calculated at the RCCSD(T) level theory for the X 2 Σ 1/2 + state of the Au–RG complexes. 10 Basis sets of d-aug-cc-pVQZ and d-aug-cc-pV5Z were employed for He, Ne and Ar. The d-aVXZ-PP basis sets were utilized, along with the small core fully relativistic effective core potentials, ECP10MDF and ECP28MDF and for Kr, and Xe. For Au the ECP60MDF_d-awCVXZ-PP basis sets were employed. The interaction energies at each internuclear separation were extrapolated to the complete basis set limit. 10. Gardner et al., J. Chem. Phys., 132, (2010)

R e / ÅD 0 / cm -1 Au–He Au–Ne [31/40] 4 Au–Ar [149  13] 5 [130  15] 7 Au–Kr [282  30] 6 [240  19] 5 Au–Xe [607  5] 5 4. Plowright et al., J. Phys. Chem. A., 114, 3103 (2010) 5.Hopkins et al., J. Chem. Phys., 132, (2010) 6. Plowright et al., J. Chem Phys., 129, (2008) 7.Knight et al., Chem. Phys. Lett., 273, 265 (1997) 10. Gardner et al., J. Chem. Phys., 132, (2010) Results: Au–RG X 2  1/2 + State

R e / ÅD 0 / cm -1 Au–He Au–Ne [31/40] 4 Au–Ar [149  13] 5 [130  15] 7 Au–Kr [282  30] 6 [240  19] 5 Au–Xe {580} [607  5] 5 4. Plowright et al., J. Phys. Chem. A., 114, 3103 (2010) 5.Hopkins et al., J. Chem. Phys., 132, (2010) 6. Plowright et al., J. Chem Phys., 129, (2008) 7.Knight et al., Chem. Phys. Lett., 273, 265 (1997) 10. Gardner et al., J. Chem. Phys., 132, (2010) Results: Au–RG X 2  1/2 + State

10. Gardner et al., J. Chem. Phys., 132, (2010) Results: Au–RG X 2  1/2 + State

Conclusions A structured (1+1) REMPI spectrum has been recorded corresponding to the D 2  3/2  X 2  1/2 + transition in Au–Ne. The expected complex transition in the vicinity of the Au 2 P 1/2  2 S 1/2 atomic transition was not observed. This is rationalized owing to the D 2  1/2 state interacting with the repulsive portion of the E 2  1/2 + state. The D 0 of the X 2  1/2 + has been found to increase with increasing RG atomic number. The R e was found to decrease with increasing RG atomic number.

Electronic Spectroscopy of the 6p ← 6s Transition in Au–Ne Richard J. Plowright, Carolyn D. Withers, Timothy G. Wright, Michael D. Morse and W.H. Breckenridge