carbene analogues

https://doi.org/10.1351/goldbook.C00807
The electrically neutral mononuclear hydrides of group 14 having two non-bonding electrons, the electrically neutral mononuclear hydrides of group 15 having four non-bonding electrons, and also the compound HB:. The names of a number of these are shown below.
 
RB: boranylidenes RAs: arsanylidenes
RN: nitrenes R2Sn: stannylidenes
R2Si: silylenes RSb: stibanylidenes
RP: phosphanylidenes R2Pb: plumbylidenes
R2Ge: germylidenes
Note that if R = H, these compounds are parent hydrides; derivatives formed by substitution are named accordingly. However, if the substituent's first atom, bearing the free valence, is of the same element as the atom of the carbene analogue, other parent compounds may be required (see carbenes ), e.g. HN: nitrene; CH3N: methylnitrene; H2NN: diazanylidene (synonym isodiazene, not aminonitrene).
Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1324 (https://doi.org/10.1351/pac199567081307)