Structure

The compound triphenylmethanol has the following functional groups: an alcohol group and an aromatic carbon-carbon double bond. The stretching of carbon-carbon double bonds of benzene rings gives a set of characteristic sharp peaks in the region.

Triphenylmethanol features three phenyl (Ph) rings and an alcohol group bound to a central tetrahedral carbon atom. All three C–Ph bonds are typical of sp3-sp2 carbon-carbon bonds with lengths of approximately 1.47 ?, while the C–O bond length is approximately 1.42 ?.

C19H16O, Mr = 260.3, trigonal, R3, a = 19.307 (3), c = 26.735 (4) ?, V= 8631 (2) ?³, Z= 24, Dx = 1.20 g cm -3, λ(Mo Ka) = 0.71073A, μ= 0.7 cm -1, F(000) = 3312, T = 294 K, R = 0.083, wR = 0.068 for 1022 observed reflections. The structure contains hydrogen-bonded pyramidal tetramers (which have approximately 32 symmetry), with one molecule lying on a crystallographic threefold axis and another in a general position. The analysis was complicated by disorder in the crystal lattice where 71% of the tetramers occupy one orientation and 29% another; these moieties have phenyl rings in the same volume elements. The O...O separations in the hydrogen-bond systems are 2.884 (10) and 2.896 (11)? in the major tetramer and 2.80 (3) and 2.90 (3) A in the minor tetramer.

The IR, 1H NMR and 13C NMR spectra character of triphenylmethanol

On IR, peaks at 3455/cm, 2960/cm, and 2873/cm showed the presence of alcohol, aromatic C-H, and sp3 C-H bonds, respectively, all of which were in the structure of triphenylmethanol. However, there was a peak of 1734/ cm, which corresponded to the C=O bond. Therefore, there might be some unreacted benzophenone reagent remaining. On 1H NMR, the multiplets around 7.3 ppm indicated the aromatic ring, and the singlet at 3 ppm proved the presence of a hydroxyl group. Information from 13C NMR reached a similar conclusion: peaks around 124ppm stood for aromatic C, and those at 78ppm stood for alcohol C.

References

[1] G. Ferguson. “The Structure of Triphenylmethanol, Ph3COH.” Acta crystallographica. Section C, Crystal structure communications 6 1 (1992): 1272–1275.