New Free‐Radical Reactions with Phosphorins

Abstract

pounds ( I ) [2,31. The C-C bond lengths in the phosphorin ring 0) agree, within experimental error, both mutually and with the C-C bond lengths in benzene. The CsP ring deviates slightly but significantly from planarity (deviations from t h e C2PC4 plane: CI, -0.11; C3, 0.07; C5, --0.02 A).The three bonds to the phenyl rings project out a little from the C2PC4 plane ( 0 , -0.33; C14, 0.17; C20, -0.20 A). The C-P-C bond angle, like that in the phosphorins ( I ) f2.31, is relatively small, having a value of 107 O ; the symmetrical variation of the remaining inner angles of the central ring is worthy of note. The O'PO2 plane is perpendicular to the ClPCs plane; the OlPO* angle of 93 is surprisingly small. The P-OCH3 bond lengths (1.57 and 1.59 A) are comparable with the P--OR