Synthesis and properties of phenyl phosphines with meta-positioned methyl groups and the X-ray structure of tris(3,5-dimethyl-4-methoxyphenyl)phosphine
Jk. Romain et al., Synthesis and properties of phenyl phosphines with meta-positioned methyl groups and the X-ray structure of tris(3,5-dimethyl-4-methoxyphenyl)phosphine, ORGANOMETAL, 19(10), 2000, pp. 2047-2050
Nine phosphines, Ph-x(3,5-dimethyl-4-R-phenyl)-(3-x) where R = N, F or OCH3
, have been synthesized, and the donor properties of the P(III) centers hav
e been evaluated by measuring the A(1) nu(CO) frequencies of the Ni(CO)(3)L
complexes. These data indicate that, compared to hydrogen, the methyl grou
ps are electron donating, the fluoro groups are electron withdrawing, and t
he methoxy groups have little effect. The X-ray structure of tris(3,5-dimet
hyl-4-methoxyphenyl)phosphine has been obtained, and a prominent feature of
the structure is that the methoxy groups are perpendicular to the phenyl r
ing faces and folded toward the ring faces adjacent to the phosphorus lone
pair.