Phenyl ion

The phenyl ion [CgHs]"", m/z 77, also undergoes C2H2 loss, thereby generating the cyclobutadienyl ion, [ 4113], m/z 51 ... 

Benzyl Halides The molecular ion peak of benzyl halides is usually detectable. The benzyl (or tro-pylium) ion from loss of the halide (rule 8, Section 2.7) is favored even over /3-bond cleavage of an alkyl substituent. A substituted phenyl ion (a-bond cleavage) is prominent when the ring is polysubstituted. 

Alkaline hydrolysis of lignin increases the number of reactive benzylic hydroxyl groups and may also be important in further depolymerizing the lignin once the oxidative-cleavage reaction has occurred. The formation of a p-electron-withdrawing -CHO substituent on aryl lignin units should increase the rate of hydrolysis of the ether bonds (26). Hydrolysis also forms p-phenylate ions, which then protect the benzaldehyde from further reaction via the Cannizzaro reaction, as mentioned earlier. 

If an aromatic molecule cannot form a benzyl ion, then the phenyl ion CeHs, m/z 77, may be formed, but formation of the benzyl ion is favoured. 

The deviation from linearity of the plot 5C vs 5C for 3,5-bis(trifluoromethyl)-phenyl ion reveals that in the equilibrium between 7 7 a it is necessary to have a... 

Several mechanisms have been suggested for the thermal decomposition reaction, such as a bimolecular reaction, carboxylation-decarboxylation, and the formation of an intermediate phenyl ion. Of these, the most acceptable is the last (Ratusky and Sorm, 1959). 

Cb, Ci8 or phenyl- Ion-suppression mode methanol bonded phase with low (acetonitrile)-water containing percentage of free 0.01-0.1 mol 1 phosphate... 

Fragmentation Characteristic H loss to yield the corresponding benzoyl ion, [M-1]+, followed by decaibonylation to a phenyl ion, [M-1-28], of lower intensity. To a small extent also decarbonylation of the molecular ion, leading to [M-28]. Weak signal at m/z 29 (CHO" "). 

Fragmentation Dominant a-cleavage to give the benzoyl ion, followed by decarbonylation to a phenyl ion of lower intensity. a-Cleavage in acetophenone also produces the acetyl cation (m/z 43). Even-mass maxima due to alkene elimination via McLafferty rearrangement. CO elimination from diaryl ketones through skeletal rearrangements. 

Fragmentation Pronounced loss of OH, leading to [M-17] and followed by decarbonylation (Am 28) to a phenyl ion of lower intensity. Water elimination to [M-18] if a H-bearing orf/io-substituent is present. Some acids decarboxylate (Am 44). Loss of CO (Am 28) from M" ". 

There have been a few reports of simple lanthanide alkyl and aryl compounds (see table 25.19). The structure of the Lu(CgH9)4 anion (CgHf = 2,6-dimethyl-phenyl ion) was discussed earlier (section 3.3). Hart and his co-workers (Hart et al., 1970a) have described some trimethyl and triphenyl complexes as well as some more complicated compounds of formula LiR(C6Hj)4. There is reasonable chemical evidence for the formation of these compounds but more physical and spectroscopic data are needed. 

Crosslinked amine/Kel-F 800 silica (not commercially available), 4.6 X 250 mm Alltech Cjj HAE weak anion exchange column, 4.6 x 150 mm, or Alltech mixed-mode RP C4, RP Cg, or RP Phenyl ion exchange columns, 4,6 x 250 mm (RP Phenyl ion exchange preferred)... 

---