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 @[email protected], is of the same element as the atom of the carbene analogue, other parent compounds may be required (see @[email protected] ), e.g. HN: nitrene; CH3N: methylnitrene; H2NN: @[email protected] (synonym @[email protected], not @[email protected]).
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1324 [Terms] [Paper]