  We report the production and spectroscopic characterization of strontium (I)
phenoxide ($\mathrm{SrOC}_6\mathrm{H}_5$, or SrOPh) and variants featuring
electron-withdrawing groups designed to suppress vibrational excitation during
spontaneous emission from the electronically excited state. Optical cycling
closure of these species, which is the decoupling of vibrational state changes
from spontaneous optical decay, is found by dispersed laser-induced
fluorescence spectroscopy to be high, in accordance with theoretical
predictions. A high-resolution, rotationally-resolved laser excitation spectrum
is recorded for SrOPh, allowing the estimation of spectroscopic constants and
identification of candidate optical cycling transitions for future work. The
results confirm the promise of strontium phenoxides for laser cooling and
quantum state detection at the single-molecule level.
