Dibenzo[b,d]phosphorin

Investigations of a highly crowded phosphino‐substituted biphenyl: A precursor for a λ3, λ5‐diphosphaphenanthrene

“…'H NMR ( ,9.10. Found: C,77.41;H,3,6, An excess of dimethylamine (about 1 mL) was added to a solution of 13 (0.25 mmol) in diethyl ether (3.0 mL) at 0°C. After 30 min, the solvents were evaporated and n-pentane (10 mL) was added.…”

“…Since 1966, aromatic heterocycles with dicoordinated phosphorus have been known in the literature. Monocyclic [ 11, bicyclic 121, and tricyclic [3] derivatives have been synthesized in several ways. Though many examples of (stable) phosphaaromatic compounds are known to date, there are very few with more than one phosphorus atom in the aromatic system.…”

10‐Phenyldibenzo[b,e]phosphorin

“…These spectra include three intense bands between 1580 and 1690 cm-1, of which one, namely 8(NH2), disappears on H/D exchange with D20; of the other two (see Table), v3(C=N) is shifted by ca. 50 cm-1 towards the red in comparison with v~(C=N) of the iminopyrazolidines (2) as a result o f the decrease in the C ---N bond order. Angew.…”

“…for (3) is shifted to lower field from its position for (2) as a result of the lesser shielding by N+ (see Table). The same is true for ( 5 ) in comparison with (4).…”

“…The N M R spectra o f the azomethine imine salts (3) contain an AzX2 system for the protons at C-4 and C-5; the N M R spectra of the iminopyrazolidines (2) contain an AA'BB' system for these protons. for (3) is shifted to lower field from its position for (2) as a result of the lesser shielding by N+ (see Table).…”