摘要：

The He(I) photoelectron (P.e.)spectra of 30 derivatives of the isoelectronic 6 -electron five-membered ring compounds 1 - 7 containing boron with the nitrogen substituents R H, CH 3 . C(CH 3 ) 3 , Si(CH 3 ) 3 , Sn(CH 3 ) 3 , B[N(CH 3 ) 2 ] 2 P(CH 3 ) 2 , P[N(CH 3 ) 2 ] 2 . As(CH 3 ) 2 R CH 3 , and the boron substituents Z H. CH 3 CI, Br, SCH 3 , OCH 3 and N(CH 3 ) 2 show a cyclic -conjugation of the ring compounds, which decreases on successive exchange of ring nitrogen atoms for ring sulfur atoms. - 11 B chemical shifts follow a linear correlation with calculated -charge densities and *-orbital energy differences of the CNDO/S model as well as vertical ionization energies of the first p.e. bands.

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