Reference Request - bond lengths in PCl2F3
To complete your literature survey, include this publication cited at least 11 times so far: «Dichlorotrifluorophosphorane (PCl2F3): molecular structure by gas-phase electron diffraction and quadratic force field» by French et al. in Inorg. Chem. 1985, 24, 2774–2777, doi 10.1021/ic00212a014.  Despite the paywall, ACS's «In lieu of an abstract, this is the article's first page.» informs you about some key properties you search, values including ($2\sigma$ estimated) e.s.d.

How did I find this publication?  Because the English Wikipedia has an entry about it (don't overlook the Chinese including complementary information).
But how to know if Wikipedia indexed such a compound?  Way better than trial-and-error is to address this question to the Wikipedia Chemical Structure Explorer allowing to query there by structure or string, which may lead you to the corresponding article (in Wikipedia).  It is backed by a public database (GitHub repository) initiated by Ertl et al.
Source: Ertl, P.; Patiny, L.; Sander, T.; Rufener, C.; Zasso M J. Cheminf., 2015, 7, 10, doi 10.1186/s13321-015-0061-y, (open access).