Table 2.
Measured (ellipsometry) and calculated (MM2, DFT) layer thickness of (oligo)phenothiazinyl thioacetates 2a, 2c–e, and 4 on Au{111}-coated silicon wafers.
| Compounda | Measured layer thickness dexpb (Å) | Calculated molecule length lmol | Calculated layer thickness dthd | Coverage θe | Monolayer | |||
| MM2 (Å) | DFTc (Å) | MM2 (Å) | DFTc (Å) | MM2 (%) | DFTc (%) | |||
| 2a | 9.0 ± 1.00 | 9.04 | 9.10 | 10.4 | 10.5 | 86.6 ± 9.56 | 86.1 ± 9.50 | Yes |
| 2c | 11.4 ± 0.99 | 17.5 | 15.3 | 18.2 | 16.2 | 62.6 ± 5.41 | 70.4 ± 6.09 | Poor |
| 2d | 18.0 ± 1.44 | 19.1 | 21.6 | 19.7 | 22.0 | 91.5 ± 7.32 | 81.9 ± 6.56 | Yes |
| 2e | 10.9 ± 1.61 | 25.5 | 22.4 | 25.6 | 22.7 | 42.6 ± 6.28 | 48.0 ± 7.07 | Poor |
| 4 | 12.9 ± 1.06 | 11.7 | 10.4 | 12.9 | 11.7 | 100.2 ± 8.22 | 110.5 ± 9.07 | Yes |
aThioacetate precursor.
bMeasured by ellipsometry. Errors given are the figures of merit of the least squares fitting routine as determined by the ellipsometer built-in software.
cDFT calculations (B3LYP/3-21G), the hexyl group was replaced by a methyl group [28]. ddth = lmol cos φ + lAu-S; lAu-S = 2.1 Å; φ anthracene-2-thiol = 23°. eθ = dexp/dth.