Table 5.
The chemical shifts from the Q-species (hydrolyzed monomers and oligomers) of TEOS and TMOS. Here, the Q represents the quaternary functional silanes. Reprinted with permission from [4]. Copyright Elsevier, 1990.
| Q0 | Si(OR)x(OH)4−x | ||||
| x | |||||
| 4 | 3 | 2 | 1 | 0 | |
| TMOS | −78.5 | −77.0 | −75.5 | −74.2 | −73.1 |
| TEOS | −81.95 | −79.07 | −76.58 | −74.31 | - |
| Q0 | Q1 | Q2 | Q3 | ||
| TMOS | |||||
| –OCH3 substituted | |||||
| Monomer Q0 | −78.47 | - | |||
| Dimer (Q1)2 | - | −85.81 | |||
| Trimer Q1Q2Q1 | −85.99 | −93.69 | |||
| Cyclic trimer (Q2)3 | −83.3 (possibly hydrolyzed) | ||||
| Cyclic tetramer (Q2)4 | −92.9 | ||||
| Linear tetramer Q1Q2Q2Q1 | −85.98 | −93.9 | |||
| Branched tetramer Q1Q3Q1Q1 | −86.19 | −102.10 | |||
| TEOS | |||||
| –OC2H5 substituted | |||||
| Monomer Q0 | −81.95 | ||||
| Dimer (Q1)2 | −88.85 | ||||
| Trimer Q1Q2Q1 | −88.99 | −96.22 | |||