Where can I find (citable) FTIR spectra of CuCl and CuCl2?
If your institution holds a subscription to Elsevier's database Reaxys, than you may find, based on chemical name, molecular formula, or CAS number (the later for example from a catalogue of a supplier of chemicals) links to primary literature in the section of spectroscopic properties. Reaxys tries to cover both organic materials (formerly deposited in the Beilstein database) and inorganic / metalorganic materials (formerly deposited in the Gmelin database).  Otherwise, Scifinder from the ACS equally points towards primary literatures, too.

Beside the databases behind a paywall, freely accessible databases like the NIST webbook may be worth to consult; the entry about $\ce{CuCl2}$ here
mentions in the references already one with IR data of gaseous $\ce{CuCl2}$ (here).