Analysis of the characteristic vibrations and their force constants (in parenthesis) as well as NMR and XRD data of [M(CO)5(NO)]+ (M: Cr, Mo, W) as [Al(ORF)4]− salts. DFT: BP86-D3BJ/def2-TZVPP C4v symmetry.
| [Cr(CO)5(NO)]+ | [Mo(CO)5(NO)]+ | [W(CO)5(NO)]+ | |
|---|---|---|---|
| IR ν(CO)a/cm−1 E | 2108 | 2099 | 2090 |
| DFT ν(CO)a/cm−1 (102 N m−1) E | 2085(34.16) | 2078(33.98) | 2070(33.71) |
| IR ν(NO)/cm−1 A1 | 1841 | 1820 | 1818 |
| DFT ν(NO)/cm−1 (102 N m−1) A1 | 1899(31.22) | 1877(30.42) | 1868(30.09) |
| DFT ν(M–N)/cm−1 (102 N m−1) A1 | 667(5.55) | 570(3.48) | 537(2.73) |
| 506(2.03) | 485(1.87) | 498(1.96) | |
| NMR (14N) δb/ppm | 17 | 3 | −15 |
| DFT (14N) δb/ppm | 35 | 43 | −30 |
| XRD d(M–C)c/pm | 195.6(4) | 208.4(3) | 207.0(6) |
| XRD d(C–O)c/pm | 112.6(5) | 112.5(3) | 113.0(8) |
| DFT d(M–C)c/pm | 193.0 | 208.3 | 207.5 |
| DFT d(C–O)c/pm | 113.9 | 114.1 | 114.2 |
a
Only the most intense CO vibration (E) is shown, force constants (in brackets) were calculated with Gaussian.
b
In oDFB solution, 298 K, CH3NO2 as reference.
c
Average of all M–C/N and C/N–O bonds due to the indistinguishable NO position in the experimental data.