Table 2. Calculated and experimental structural parameters for the dimetallenes [E{CH(SiMe3)2}2]2 (E = Ge, Sn, or Pb), in which the E{CH(SiMe3)2} units have the syn, anti (E = Ge or Sn) or syn, syn (Pb) configuration.
| [Ge{CH(SiMe3)2}2]2 | ||||
| B3PW91 | B3PW91-D3 | B97-D3 | X-ray a | |
| E–E (Å) | 2.373 | 2.315 | 2.376 | 2.347(2) |
| E–C (Å) | 2.022 (avg.) | 2.001 | 2.042 (avg.) | 2.01(3) |
| C–E–C (°) | 109.9 | 111.8 | 111.0 | 112.5(3) |
| C–E–E (°) | 114.3 | 113.8 | 112.6 | 113.7(3) |
| 122.5 | 120.5 | 119.8 | 122.3(2) | |
| C–E–E–C (°) | –43.0 | –43.1 | –46.6 | –39.5(3) |
| 180.0 | 180.0 | 180.0 | 180.0(3) | |
| Trans-bending angle (°) | 34.3 | 35.7 | 38.8 | 32 |
| [Sn{CH(SiMe3)2}2]2 | ||||
| B3PW91 | B3PW91-D3 | B97-D3 | X-ray b | |
| E–E (Å) | 2.777 | 2.694 | 2.774 | 2.768(1) |
| E–C (Å) | 2.230 (avg.) | 2.198 | 2.255 (avg.) | 2.216 (avg.) |
| C–E–C (°) | 109.8 | 111.2 | 109.8 | 109.2(2) |
| C–E–E (°) | 113.5 | 113.4 | 112.2 | 112.0(1) |
| 120.8 | 118.2 | 117.6 | 119.4(1) | |
| C–E–E–C (°) | –46.4 | –47.2 | –51.2 | –50.5(1) |
| 180.0 | 180.0 | 180.0 | 180.0(1) | |
| Trans-bending angle (°) | 37.6 | 39.7 | 42.9 | 41 |
| [Pb{CH(SiMe3)2}2]2 | ||||
| B3PW91 | B3PW91-D3 | B97-D3 | X-ray c | |
| E–E (Å) | 6.673 | 3.241 | 3.256 | 4.129(1) |
| E–C (Å) | 2.368 (avg.) | 2.357 (avg.) | 2.383 (avg.) | 2.313(5) |
| 2.323(5) | ||||
| C–E–C (°) | 96.8 (avg.) | 91.3 (avg.) | 91.8 (avg.) | 93.4(2) |
| C–E–E (°) | 122.7 (avg.) | 116.9 (avg.) | 118.0 (avg.) | |
| C–E–E–C (°) | –54.6 (avg.) | –73.8 (avg.) | –71.5 (avg.) | –55.70 |
| 171.3 (avg.) | 179.2 (avg.) | 179.3 (avg.) | 180.0(1) | |
| Trans-bending angle (°) | 35.6 | 49.9 | 47.8 | 34 |