▁contrast ▁to ▁car ben es , ▁which ▁often ▁have ▁a ▁triple t ▁ground ▁state ▁and ▁readily ▁dim er ize ▁to ▁form ▁al ken es . ▁ ▁In ▁dim eth yl le ad , ▁( CH 3 ) 2 P b , ▁the ▁P b – C ▁bond ▁length ▁is ▁ 2 . 2 6 7   Å ▁and ▁the ▁C – P b – C ▁bond ▁angle ▁is ▁ 9 3 . 0 2 ° ; ▁the ▁sing let – tri ple t ▁gap ▁is ▁ 3 6 . 9 9   k cal   m ol − 1 . ▁ ▁Di phen yl le ad , ▁( C 6 H 5 ) 2 P b ▁was ▁computed ▁with ▁G AME SS ▁at ▁the ▁B 3 P W 9 1 ▁level ▁of ▁theory ▁using ▁the ▁basis ▁sets ▁ 6 - 3 1 1 + G ( 2 df , p ) ▁for ▁C ▁and ▁H ▁and ▁def 2 - sv p ▁for ▁P b ▁with ▁the ▁E CP 6 0 M DF ▁pseud op ot ential , ▁in ▁an ▁adapted ▁procedure ▁( which ▁uses ▁the ▁cc - p V T Z ▁basis ▁set ▁for ▁P b ▁instead ). ▁The ▁mole cular ▁orbit als ▁( MO s ) ▁( visual ized ▁using ▁Ch im era ) ▁and ▁natural ▁bond ▁orbit als ▁( N BO s ) ▁( visual ized ▁using ▁multi w fn ) ▁generated ▁are ▁produced ▁below , ▁and ▁qual it atively ▁identical ▁to ▁the ▁literature . ▁As ▁expected , ▁the ▁H OM