Pathway Towards Optical Cycling and Laser Cooling of Functionalized Arenes

Multivalent optical cycling centers in polyatomic molecules

“…Second, the highly polar metal-ligand bond polarizes the unpaired cycling electron away from the bond, decoupling it from the rest of the molecule. Indeed, it has been widely suggested in the cold molecule community that the existence of a highly polar bond between the OCC and ligand may be an important condition for diagonal FCFs and laser coolability [9,18,19,[22][23][24][27][28][29].…”

“…Synthesis of larger polyatomics could potentially involve using gas-phase methanethiol, (HSCH 3 ), ethanthiol (HSC 2 H 5 ), pentadienyl (C 5 H 5 ), or benzene (C 6 H 6 ) precursors, in a similar manner to the production of oxygen-containing polyatomics with capillary-introduced alcohol reactants (i.e. CH 3 OH, C 2 H 6 O) [28,29,143,150,[178][179][180][181][182]. Cryogenic yields can be further enhanced via state-selective excitation of reactants, as was demonstrated in the buffer-gas synthesis of YbOH molecules [183,184].…”

“…Preliminary results suggest that large, multivalent MSR-type molecules also exhibit structural features conducive to photon cycling, including OCClocalized frontier orbitals with visible-wavelength energy spacings. Combining multi-electron OCC structure with complex electronic ligand degrees of freedom, such as via hypermetallic functionalization [20,21], or tuning Franck-Condon factors via ligand substitution [22,[27][28][29]] offers yet more unexplored design space.…”

“…Figure 11. Proposed rotational repumping scheme based on optical transitions identified for (a) 27 AlSH, (b) 28 SiSH, and (c) 31 PSH in Fig. 5.…”

“…In the last five years, laser cooling and optical control have been extended to increasingly complex polyatomic molecules, paving the way towards the high phase space density [13,14] and coherent quantum control [15][16][17] necessary for realizing science applications with cold gases of optically active polyatomic molecules. Simultaneously, theoretical understanding of the features that make molecules amenable to optical cycling and laser cooling has significantly advanced [18][19][20][21][22][23][24][25][26][27][28][29], leading to the identification of several classes of polyatomics with favorable chemical and structural configurations.…”